■u. S. MR DEPT. TECHNICAL MANUAL 8-635 
BLOOD »««« OBIT TO @ 
mJ 
WAR DEPARTMENT TECHNICAL MANUAL 
BLOOD REFRIGERATION 
UNIT REFRIGERATOR 
(MEDICAL DEPARTMENT ITEM NUMBER 9960110) 
WAR DEPARTMENT 
APRIL 1945 WA R DEPARTMENT TECHNICAL MANUAL 
T M 8-633 
BLOOD REFRIGERATION 
UNIT REFRIGERATOR 
(MEDICAL DEPARTMENT ITEM NUMBER 9960110) 
WAR DEPARTMENT 
1 APRIL 1943 WAR DEPARTMENT 
Washington 25, D. C., 1 April 1945 
TM 8-635 Blood Refrigeration Unit Refrigerator (Medical Department 
Item No. 9960110), is published for the information and guidance of all 
concerned. 
[AG 300.7 (18 Apr 45)] 
order of the Secretary of War: 
Official: 
G. C. MARSHALL 
Chief of Staff 
J. A. ULIO 
Major General 
The Adjutant General 
Distribution: 
AAF (5); AGF (5); ASF (2); T of Opns (10); 
Dept (10); Base C (5); S Div ASF (1); SvC (5); 
PE (2); ASF Dep (Med Sec) (10); Dep 8 (Com) 
(25) except St. Louis Med Dep (75); GH (4); SH 
(2); Evac H (3); Conv H (2); Fid H Unit (2); 
Port Surg H (2); USMA (2); Lab 8 (Army) (1); 
Gen Lab 8 (1); A (2): CHQ (2); AF (5); T/O&E 
8-187 (2); 8-510 (2); 8-550 (4); 8-560 (2): 8-527S 
(2); 8-580 (3); 8-581 (3); 8-590 (2): 8-610 (1); 
8-611 (1); 8-667 (2) 
For explanation of symbols, see FM 21-6. TABLE OF CONTENTS 
PART ONE 
INTRODUCTION 
Paragraph 
Page 
SECTION I. GENERAL. 
Scope 1 1 
Records 2 2 
SECTION II. REFRIGERATION AND CONTROL CYCLE. 
Theory of Refrigeration 3 3 
Explanation of Refrigeration Cycle 4 3 
Explanation of High and Low Side of the System 5 6 
Electrical Wiring 6 6 
SECTION 111. DESCRIPTION AND DATA. 
General Description of Refrigerator 7 7 
Description of the Main Parts of the Refrigerator 8 7 
Data 9 13 
PART TWO 
OPERATING INSTRUCTIONS 
SECTION IV. GENERAL. 
Scope • 10 14 
SECTION V. SERVICE UPON RECEIPT OF EQUIPMENT. 
Uncrating Unit and Placing Accessories 11 14 
Preparation of the Refrigeration System 12 16 
SECTION VI. CONTROLS AND INSTRUMENTS. 
Temperature Controls 13 16 
Control Adjustments by Operating Personnel 14 17 
Thermostatic Expansion Valve 15 17 
Instruments 16 17 
SECTION VII. OPERATION UNDER USUAL CONDITIONS. 
Operation 17 18 
SECTION VIII. OPERATION UNDER UNUSUAL 
CONDITIONS. 
Dust and Sand 18 18 
Extreme Temperature Conditions 19 18 
PART THREE 
MAINTENANCE INSTRUCTIONS 
SECTION IX. GENERAL. 
Scope 20 19 SECTION X. LUBRICATION. 
General Instructions 21 19 
Motor Lubrication 22 19 
Compressor Lubrication 23 19 
SECTION XL PREVENTIVE MAINTENANCE. 
Organizational Maintenance (2nd Echelon) 24 19 
SECTION XII. TROUBLE SHOOTING. 
Valves and Gages 25 20 
Diagnosis of Refrigeration Trouble 26 22 
Refrigeration Trouble Chart 27 22 
SECTION XIII MAINTENANCE OPERATIONS. 
Paragraph Page 
Inspecting and Defrosting Evaporator 28 25 
Inspecting and Cleaning Condenser 29 26 
Resetting Refrigeration Thermostatic Control 30 26 
Replacing Motor Brushes 31 26 
Inspecting and Cleaning Motor Commutator 32 27 
Inspecting and Adjusting Belt 33 27 
Tightening Thermostatic Bulb Clamp 34 28 
PART FOUR 
AUXILIARY EQUIPMENT 
SECTION XIV. GENERAL. 
Blood Refrigeration Unit Generator 35 29 
PART FIVE 
REPAIR INSTRUCTIONS 
SECTION XV. GENERAL. 
Scope 36 30 
SECTION XVI. TROUBLE SHOOTING. 
Refrigeration Trouble Chart 37 30 
SECTION XVII. REPAIR OF REFRIGERATION SYSTEM. 
Installing the Gages 38 33 
Operating the Leak Detec tor 39 35 
Testing for Leaks 40 37 
Pumping Down the System 41 38 
Balancing the Pressure for Compressor Repairs 42 39 
Purging Air from the System 43 40 
Adding and Removing Refrigerant from the System 44 42 
Adding Oil to the Compressor 45 45 
Servicing the Dehydrator 46 46 
Servicing the Evaporator 47 47 
Controls 48 51 
IV Servicing the Heater Unit 49 59 
Servicing the Thermostatic Expansion Valve 50 62 
Servicing the Cylinder Head Suction Strainer 51 64 
Servicing the Cylinder Head Valve Plate Assembly 52 66 
Servicing the Compressor Service Valves 53 68 
Servicing the Liquid Receiver 54 71 
Servicing the Condenser 55 73 
Servicing the Compressor Belt 56 73 
Servicing the Compressor Assembly 57 75 
Servicing the Electric Motor 58 92 
SECTION Will. CABINET REPAIRS. 
Servicing the Cabinet 59 104 
APPENDIX 
SECTION I. PREPARATION FOR STORAGE 
OR SHIPMENT. 
Preparing the Refrigeration System GO 109 
Preparing the Refrigerator Storage Compartment 61 109 
SECTION II. REFERENCES. 
Field and Technical Manuals 62 109 
Abbreviations 63 110 
INDEX Ill PART ONE 
INTRODUCTION 
Section I 
General 
1. SCOPE 
o. Contents of Manual. These instructions are published for the 
information and guidance of the personnel to whom this equipment is 
assigned. They contain information on the operation and maintenance 
of the equipment as well as descriptions of the major units and their 
functions in relation to the other components of the equipment. They 
apply only to the Unit, Blood Refrigeration, Refrigerator: Medical 
Department Item No. 9960110. These instructions are arranged in five 
parts: Part One, Introduction; Part Two, Operating Instructions; Part 
Figure 1. Unit, blood, refrigeration, refrigerator. 
Med. Dept. No. 
/. 
2. 
3- 9R2JO38 
4. 9R2"JOIO 
Nomenclature 
Cabinet skids 
Tmv and lifting rings 
Thermometer, diaI 
Handles, lift, cabinet 
1 Three, Maintenance Instructions; Part Four, Auxiliary Equipment (does 
not apply) and Part Five, Repair Instructions. 
b. List of Publications. Publications applicable to the material cov- 
ered by this manual are listed in the Appendix. Those parts of illustra- 
tions keyed with Medical Department numbers and formal nomen- 
clature are regularly supplied as spare parts. All requisitions for spare 
parts should be submitted in accordance with latest A.S.F. Supply 
Catalog Med-7. 
c. Importance of Manual. Refrigeration servicing and repair wor k 
differ from most other mechanical servicing in that the system must be 
kept free of air, dirt and moisture. Considerable damage may result if 
operation, adjustment or repair of the refrigeration system is attempted 
without thorough study of specific directions for servicing. 
2. RECORDS 
No records are required to be kept on this item except as may be 
designated by the Medical Officer in charge. 
Figure 2. Storage compartment, 
Med. Dept. No. 
1. 9R27050 
2, 
Nomenclature 
Racks, bottle 
Thermometer bulb 
2 Section 11 
Refrigeration and Control Cycle 
3. THEORY OF REFRIGERATION 
a. The boiling or evaporation is a cooling process. When enough heat 
is applied to am liquid, the liquid absorbs the heat and becomes a gas. 
When ordinary water is placed over a flame the water absorbs heat and 
evaporates, thus becoming steam. All the water will finally boil away or 
evaporate if left on the flame for a period of time. If pure water is boiled 
at sea level, it will boil at a temperature of 212 degrees Fahrenheit. 
b. In refrigeration machines, the evaporation or boiling of a liquid is 
the cooling process. In substitution for water, liquids that boil at much 
lower temperatures than 212 degrees Fahrenheit are used. 
c. Gas, F-12, 25 gallon drum, 9R20008, or Freon 12, as it is called, is 
the refrigerant used in this piece of equipment and will boil at minus 21.7 
degrees Fahrenheit. If liquid Freon 12 were placed in an open container 
the liquid would boil producing a temperature of minus 21.7 degrees 
Fahrenheit. If this container of Freon 12 were placed in a temperature 
below 2 1.7 degrees Fahrenheit, the refrigerant would not boil for the heat 
in the air would not be sufficient. 
d. The heat leaking through the cabinet walls or the heat emitted 
from the stored products is sufficient to cause the refrigerant to boil. 
Refrigerant in this piece of equipment is contained in a set of cold plates 
called the “evaporator” and make up the walls of the container racks. 
e. Since it is not practical for refrigerants 10 be permitted to boil away 
or pass into the atmosphere, it is necessary to reclaim them and use them 
over. Obviously, the refrigerant in the gas form, laden with heat, must be 
condensed or changed back into a liquid to facilitate its re-use. This is 
done by pumping the gas to a set of coils known as the “condenser”, in 
which the gas is cooled and liquified and then is stored in a tank called 
the “liquid receiver” where it is held until needed in the evaporator. 
4. EXPLANATION OF REFRIGERATION CYCLE 
o. The cycle of refrigeration in this compression system is clearly 
shown in fig 3, and a description of the fundamentals is embodied in the 
following paragraphs: 
b. Begin with the evaporator unit marked “A”. Heat will not flow 
from one body of matter to a body of higher temperature. Wherever a 
difference in temperature exists the flow of heat will be from the warmer 
body to the cooler body. 
c. As the pressure on the surface of any liquid is reduced, the liquid 
will boil at a lower temperature and conversely, as the pressure increases 
the boiling temperature increases. By regulating the pressure in the 
3 evaporator the boiling of Freon 12 refrigerant can be controlled. Since 
temperature is directly dependent upon pressure, we can control the 
temperature in the refrigerator by the pressure maintained in the evap- 
orator. The evaporator is therefore kept at a lower temperature by the 
boiling refrigerant in the unit, and there is a continual flow of beat to it 
from the air in the cabinet. 
Figure 3. Refrigeration cycle. 
4 d. As the refrigerant changes from a liquid to a gas, the compressor 
“C” draws the gas through the suction line “B", and compresses it through 
the discharge line “D”. It then passes into the condenser “E” and is con- 
densed back to a liquid due to the increase of pressure from the com- 
pressor and the removal of the heat from the gas by the action of the fan 
“I” passing over the condenser. To condense gas simply by removal of 
heat is not practical, nor is it practical to condense the gas by increasing 
pressure. For these reasons the refrigerant is condensed by both methods 
combined. The pressure is increased by the compressor and the heat is 
removed from the gas to the atmosphere by passing air over the condenser 
with a fan. 
e. The liquid refrigerant then flows into the liquid receiver “F” where 
it is stored under pressure until more liquid is needed in the evaporator 
“A”. When the need for refrigerant in the evaporator arises, the expan- 
sion valve “H” allows the liquid to flow from the liquid line “G” into the 
evaporator “A” under low pressure, where it again boils and begins 
another cycle through the system. 
Figure 4. Refrigerant flow chart. 
5 5. EXPLANATION OF HIGH AND LOW SIDE OF THE SYSTEM 
o. T here are two pressures in the system—a low and a high pressure 
(hg 4). All the equipment from the discharge side of the compressor up to 
the expansion valve is the high pressure side; and from the expansion 
valve to the discharge side of the compressor is the low pressure side. 
6. ELECTRICAL WIRING 
o. The refrigeration thermostatic control, 9R27190, the low pressure 
control, 9R27202, and the condensing unit motor, 9R27152 (fig 6), are 
wired in series. The heater thermostatic control, 9R27056 (fig 6), is wired 
in the line ahead of the other two controls (see Wiring Diagram fig 5). 
WIRING DIAGRAM FOR 
UNIT, BLOOD REFRIGERATION, REFRIGERATOR 
Figure 5. Wiring diagram. 
6 b. Control adjustments are set to permit refrigeration to be controlled 
by the refrigeration thermostatic control and heat by the heater thermo- 
static control without conflict. The low pressure control is adjusted to 
serve only as an emergency cut-out to prevent a freeze-up in the storage 
compartment should the refrigeration thermostatic control fail to stop 
the unit. The low pressure control will also stop the unit in the event of 
a refrigerant loss. 
c. The condensing unit motor is equipped with an automatic overload 
protector switch (fig 65, item 5). The purpose of this overload protector 
switch is to open the circuit to the condensing unit motor should an over- 
load be imposed upon the motor. 
Section III 
Description and Data 
7. GENERAL DESCRIPTION OF REFRIGERATOR 
a. Purpose. This refrigerator is designed specifically for the storage 
of whole blood and is maintained at an average temperature of 43 degrees 
Fahrenheit in the cooled compartment. The storage compartment con- 
tains 10 bottle racks (fig 2, item 1) with a capacity of 5 bottles each, or a 
total capacity of 50,500 cc or 1000 cc bottles of whole blood. The cooling 
temperature is maintained by a condensing unit of 14 horsepower located 
in the bottom of the cabinet (fig 9, item 13). In addition to the refrigeration 
system, a heating unit is located in the storage space (fig 8, item 5) to pro- 
vide heat should the surrounding temperature be low enough to produce 
an inside temperature lower than that desired. Handles (fig 1, item 4) are 
provided on each side of the cabinet to facilitate moving. The cabinet is 
also equipped with tow and lifting rings (fig 1, item 2) extending from 
the skids (fig 1, item 1). General physical characteristics are shown in fig 1. 
b. Manufacturer. This item is manufactured for the Medical Depart- 
ment by Mills Industries, Incorporated, 4100 Fullerton Avenue, Chicago 
39, Illinois. 
8. DESCRIPTION OF THE MAIN PARTS OF THE REFRIGERATOR 
a. Evaporator. The interior of the storage compartment is equipped 
with an evaporator (fig 8, item 2) which serves also as the partitions and 
supporting brackets for shelves for the bottle racks. The construction and 
design is such that the refrigerated plates of the assembly permit rapid 
transfer of heat from the racks through the supporting shelves and into 
the refrigerant contained within the walls of each section. 
b. Racks. The sliding, removable bottle racks (fig 2, item 1) are de- 
signed to hold 2 types of 500 cc bottles, and 1 type of 1000 cc bottles. 
Springs are arranged to hold bottles securely during transportation. 
7 Figure 6. Condensing unit, front view. 
Med. Dept. No, 
1. 9R2/O56 
2. C)R2JIC)0 
3- 
~f. 9R2J202 
5. r)R2J200 
6. 9R27152 
Nomenclature 
Control, thermostatic, heater 
Control, thermostatic, refrigeration 
Manual corn part men t 
Control, pressure, low 
Valve, drain, shutoff 
Motor, electric, complete 
c. Shelves. Removable shelves (fig 8, item i) are provided between the 
plates to serve as slides for the bottle racks. By removing these shelves it 
is possible to clean the compartment. A drain in the bottom of the com- 
partment has been provided for the'removal of excess cleaning substance. 
A drain valve (fig 6, item 5) is provided on the outlet end of the drain to 
prevent warm air from entering the cabinet. This valve must be kept 
closed during normal operation. 
8 Figure 7. Condensing unit, rear view, with tube channel cover removed. 
d. Heater Unit. A heater unit (fig 8, item 5) has been incorporated in 
the refrigerator so that in case this equipment should be operated in 
temperatures lower than the desired temperature for the storage of blood, 
the refrigeration mechanism automatically shuts off and the heater unit 
automatically operates. This heater unit is independent of the refrigera- 
tion equipment and is connected through the junction box dir ect to the 
main field line and is not wired through the refrigeration and low pres- 
sure controls. It the refrigeration mechanism becomes inoperative or out 
of adjustment resulting in too cold a temperature in the storage space, 
the thermostatic control governing the heater unit will automatically 
turn on the heater, counteracting the refrigeration effect. Conversely, if 
the heater cm it control should become inoperative or out of adjustment 
leaning toward too warm a storage temperature, the refriger ation ther- 
mostatic control automatically starts itr the refrigerating unit. 
e. Indicating Dial Thermometer. Installed in the lace of the refrig- 
erator door (fig i, item 3) is an indicating dial thermometer to indicate if 
the refrigerator is in operating condition. 
9 Figure 8. Heating unit and cabinet interior. 
Med. Dept. No. 
1. 9R2/O48 
2. 9R 27046 
5. 9R27188 
9R27058 
5. 9R27054 
Nomenclature 
Shelves, evaporator 
Evaporator, complete 
Valve, expansion, thermostatic 
Clamp, Ihermostatic 
Element, heating 
t. Condensing Unit. The condensing unit (fig 9) is equipped with a 
14 horsepower repulsion induction motor. A vertical reciprocating type 
compressor is driven by the motor and a V-belt. The receiver is of vertical 
type and an air-cooled condenser is used. To dissipate the heat from the 
condenser and the motor, air is drawn into the machine compartment 
from the rear and discharged through the front by a suction fan mounted 
on the end of the motor shaft. T he mechanical equipment is arranged to 
facilitate access for service and adjustments. 
g. Manual Compartment. A pocket for the service manual, extra 
belt, oil can, and a brush for cleaning the condenser is attached to the 
left wall of the machine compartment (fig 6 and 10). 
h. Cabinet Serial Number. The cabinet serial number is stamped on 
the top of the front skid (left-hand corner when facing the cabinet), and 
can be read from the outside ©f the refrigerator (fig 11). 
10 Figure 9. Condensing unit. 
Med. Dept. No 
1. ()R2*j202 
2. 9R2J144 
3. () R23210 
q. (JR2J222 
5. 9R27208 
6. <jR2y2I2 
7. 0R2J2O6 
8. ()R2yiq8 
9- 
10. (JR2J132 
11. ()R2Jo62 
12. qR2jo6o 
13. (jR2y20q 
Nomenclature 
Control, low, pressure 
Belt, corn pressor 
Valve, receiver, liquid 
Dehydrator 
Receiver, liquid 
Plug, fuseable, receiver 
Condenser 
Fan, motor, electric 
Electric motor oil cups 
Motor, electric, complete 
I 'a bees, service 
Compressor, complete | less fiywheei 
Condensing unit, complete 
11 Med. Dept. No. 
1. TR01034 
2. 9R27144 
5. TR0252I 
4. T MS-6y5 
Figure 10. Manual compartment accessories 
Nomenclature 
Brush, hair, 6 inch, handle 
Belt, compressor 
Oiler, steel, straight spout, i/2 pint 
Manual, technical 
Figure 1 1. Cabinet serial number. 
12 9. DATA 
a. Refrigerator Dimensions Overall, Exclusive of Skids: 
Width — 36 inches including carrying handles 
Height — inches 
Depth — 341/2 inches including door latch 
b. Overall Dimensions Including Skids: 
Height — 45 1/9 inches 
Width — 44 inches 
c. Inside Dimensions: 
Height — 20.% inches 
Width — 281/2 inches 
Depth — 25 inches 
d. Overall Shipping Dimensions with Export Packing: 
Height — 5834 inches 
Width — 51 inches 
Depth — 4014 inches 
e. Weight: 
880 pounds —shipping weight with export packing 
568 pounds — net weight less blood and bottles 
f. Condensing Unit: 
Motor type, repulsion—induction 
Motor rating, 14 horsepower 
Motor voltage, 110 volts, alternating current, 60 cycle 
Motor speed, 1725 R.P.M. 
Motor pulley diameter, 214 inches 
Compressor flywheel diameter, 934 inches 
Compressor speed, 350 R.P.M. 
Cylinder bore and stroke, 11/2 inches x 1 \/2 inches 
Normal wattage consumption, 340 watts with an evaporator tem- 
perature of 39 degrees Fahrenheit, and the surrounding temper- 
ature 75 to 80 degrees Fahrenheit 
Compressor oil charge, 1 ?/4 pints refrigeration oil 
Refrigerant charge, Freon 12—2 14 pounds 
g. Capacity: 
Storage capacity, 50 bottles 500 cc or 1000 cc 
13 PAR T TWO 
OPERATING INSTRUCTIONS 
Section IV 
General 
10. SCOPE 
a. Part Two contains information for the guidance of the personnel 
responsible for the operation of this equipment. It contains information 
on the operation of the equipment together with description and location 
of various controls and instruments. 
b. Failure or unsatisfactory performance of equipment will be re- 
ported on W.D., A.G.O. Form 468. If this form is not available see 
TM 38-250. This form will be made out in duplicate by using or service 
organization and forwarded in duplicate through command channels to 
The Surgeon General. 
Section V 
Service Upon Receipt of Equipment 
11. UNCRATING UNIT AND PLACING ACCESSORIES 
a. Uncrating the Refrigerator. The crated refrigerator should be 
moved to the location of operation before being uncrated. When the 
refrigerator is to be used the crate must be removed (fig 12) and the 
following steps taken to prepare the refrigerator for operation. To remove 
the crate proceed as follows: 
(1) Remove the 3 steel bands with a pinch bar or similar tool. 
(2) With a nail puller remove all nails from the 4 sides and the top. 
(3) Remove the packing brace framed around the top of the 
cabinet. 
(4) To remove the refrigerator from the packing base, work from 
the under side of the base, and by tilting the refrigerator for- 
ward and back the 4 J-bolt nuts can be removed, allowing the 
4 J-bolts to be free for removal (fig 12, item 1). 
(5) With the J-bolts removed, the refrigerator is now free and can 
be lifted from the packing base. 
b. Placing Accessories 
(1) Remove the screws from the front and rear machine compart- 
ment doors and lift off the doors. 
(2) Remove all tape and packing from the controls, motor, junc- 
14 tion box, drain shutoff valve, extension cord plug, and the 
packing between the compressor flywheel and belt. 
(3) Open storage compartment door by removing the pin from the 
latch and remove the packing from the 10 bottle racks. 
(4) Remove the cardboard box containing the brush, oil can and 
belt (fig 10). Place these articles in the manual compartment 
(fig 6, item 3) provided for this purpose. 
(5) Slide the racks into position between the evaporator plates 
(fig 2). 
(6) Reinstall the rear machine compartment door. 
Figure 12. Uncrating refrigerator. 
i. J-Bolts 
15 12. PREPARATION OF THE REFRIGERATION SYSTEM 
o. The following steps must be taken to prepare the refrigeration 
system for operation. All 3 valves have been closed for shipment and 
must be opened before the unit is placed in operation or serious damage 
will result. 
(1) Place the refrigerator in position. To lift, use the 4 handles 
attached to the cabinet sides. If the refrigerator is installed 
indoors, air circulation must be provided to the condensing 
unit. To provide this air circulation install the refrigerator at 
least 1 foot away from the wall. 
(2) Pull the extension cord through the cabinet. 
(3) Remove the 3 valve stem caps as indicated by tags (2 on the 
compressor head and 1 on the liquid receiver valve) (fig 9, 
items 3 and 11). 
(4) Back seal all 3 valve stems to a firm seat. (See par 25.) (Use 
ratchet wrench, TR02314—not pliers.) 
(5) Reinstall valve stem caps (tighten with wrench). 
(6) Place 6 drops of “OE 10 engine oil” in oil cups located on each 
end of the motor (fig 9, item 9). 
(7) Electric supply must correspond with voltage and cycle as in- 
dicated on name plate attached to the condensing unit (no 
volts, alternating current, 60 cycle, 1 phase). 
(8) Connect extension cord plug to the source of supply. The unit 
is now in operation. 
(9) Reinstall the front machine compartment door. 
Section VI 
Controls and Instruments 
13. TEMPERATURE CONTROLS 
a. The control system consists of 2 thermostatic controls and 1 pres- 
sure control (fig 6). 
(1) The refrigeration thermostatic control (fig 6, item 2) is set to 
maintain a temperature from 4 degrees Centigrade (49.2 Fahr- 
enheit) to 8 degrees Centigrade (46.4 Fahrenheit). 
(2) The fow pressure control (fig 6, item 4) is adjusted to maintain 
a temperature of approximately 3 degrees Centigrade (374 
Fahrenheit) to 7 degrees Centigrade (44.6 Fahrenheit). 
(3) The heater thermostatic control (fig 6, item 1) is set to maintain 
a temperature of 2 degrees Centigrade (35.6 Fahrenheit) to 6 
degrees Centigrade (42.8 Fahrenheit). 
16 fa. Thus h is possible to maintain the temperature at the setting desig- 
nated on the refrigeration thermostatic control. If the refrigeration ther- 
mostatic control fails to open the electrical circuit, the low pressure con- 
trol will automatically stop the condensing unit. Should the refrigeration 
thermostatic control and the low pressure control both fail to stop the 
condensing unit, the heater unit will automatically be put into operation 
by the heater thermostatic control. If the equipment is subjected to ab- 
normal low temperatures the heater unit will prevent heat leakage from 
lowering the temperature of the refrigerator compartment to a point of 
freezing. Control settings are set so as to energize the heater at 2 degrees 
Centigrade (35.6 Fahrenheit) and shut off the heater at 6 degrees Centi- 
grade (42.8 Fahrenheit). 
14. CONTROL ADJUSTMENTS BY OPERATING PERSONNEL 
0. The refrigeration thermostatic control and the heater thermostatic 
control are equipped with linger tip adjustment knobs with limits of 4 
degrees Fahrenheit above and 4 degrees Fahrenheit below factory set- 
tings. The operating personnel are limited to these adjustments. 
fa. These adjustment knobs are external and are located on top of the 
controls. The knobs are equipped with stops to maintain their limits, 
and no further adjustments than those afforded by the external knobs 
are to be attempted by the operating personnel. Raising or lowering the 
temperature setting in this manner does not affect the differential settings. 
NOTE: ALTITUDE LOWERS CONTROL SETTINGS 1 DEGREE 
FAHRENHEIT PER 1000 FEET. 
15. THERMOSTATIC EXPANSION VALVE 
The thermostatic expansion valve is mounted on the evaporator at the 
left rear of the cabinet (fig 8, item 3). This valve is adjusted to maintain 
full refrigeration of the evaporator. The amount of refrigerant entering 
the evaporator is governed by the temperature of the thermostatic bulb 
attached to the suction line at a predetermined point for proper control 
(fig 8, item 4). 
16. INSTRUMENTS 
The thermometer installed in the face of the refrigerator door is an 
indicating dial thermometer (fig 1, item 3). The purpose of this ther- 
mometer is to indicate if the refrigerator is in operating condition. Tem- 
peratures indicated on the dial are those represented from the reaction 
of the bidb mounted on the inside panel of the door (fig 2, item 2). When 
the refrigerator is in operation, the indicating hand should be within the 
range of the operating temperature of the compartment. If the refriger- 
ator door is opened and closed frequently, or if the lapse of time from 
original start-up is not sufficient for the temperature to reach the pre- 
determined required point, the dial will indicate a temperature higher 
17 than that required for normal operation. Therefore, these conditions 
must be considered before assuming that the equipment is not operating 
properly. NO ATTEMPT SHOULD BE MADE TO ADJUST THE 
CONTROLS USING THE INDICATING DIAL THERMOMETER 
AS A SETTING INSTRUMENT. THE DIAL THERMOMETER 
INDICATES ONLY A RELATIVE CONDITION. Although the 
indicating dial thermometer was properly calibrated at the time it left 
the factory, its accuracy may be impaired by unusual conditions and 
handling. However, it is sufficiently rugged to function as an indicating 
instrument within the limits of its requirements. 
Section VII 
Operation Under Usual Conditions 
17. OPERATION 
Lite operation of the refrigerator is automatic. No attempt should be 
made to start the condensing unit before the start-up instructions (see 
par 12) have been read and completely followed. Reinspect to be certain 
that all 3 valve stems are back to a firm left seat. With the 3 valves opened, 
the valve stem caps replaced, begin operation by inserting the extension 
cord plug into 110 volt, alternating current, 60 cycle, 1 phase current 
supply. 
Section VIII 
Operation Under Unusual Conditions 
18. DUST AND SAND 
When operating under extreme dust and sand conditions, the con- 
denser must be inspected and cleaned daily. To clean the condenser see 
par 29. 
19. EXTREME TEMPERATURE CONDITIONS 
o. High Temperature Conditions. Under extremely high tempera- 
tines caused by the weather or room conditions, the condensing unit will 
be operating longer cycles than normally. When operating under these 
extreme conditions, the machine compartment doors may be removed 
for better circulation of cooling air over the condensing unit. 
b. Low Temperature Conditions. If the refrigerator is subjected to 
abnormal low temperature conditions, the heater thermostatic control 
will automatically energize the heater unit and prevent heat leakage from 
lowering the temperature of the refrigerator compartment to a point of 
freezing. 
18 PART THREE 
MAINTENANCE INSTRUCTIONS 
Section IX 
General 
20. SCOPE 
Part Three contains information for the guidance of the personnel of 
the using organizations responsible for the maintenance (ist and 2nd 
echelon) of this equipment. It contains information needed for the per- 
formance of the scheduled lubrication and preventive maintenance serv- 
ices. 
Section X 
Lubrication 
21. GENERAL INSTRUCTIONS 
To prevent personal injury, the following precautions must be fol- 
lowed. Before any lubrication is attempted, disconnect the extension cord 
plug from the source of supply. If the plug is not disconnected, the auto- 
matic controls may start the unit at any instant and cause serious injury 
to the operating personnel reaching around the licit, fan and flywheel. 
22. MOTOR LUBRICATION 
Once a month, place 6 drops of “OE 10 engine oil" (fig 10, item 3) in 
the 2 oil cups located on the bearing ends of the electric motor (fig 9, 
item 9). 
23. COMPRESSOR LUBRICATION 
It is seldom necessary to add oil to the refrigerating system since the oil 
is in a closed system at a temperature not conducive to carbonization. 
Replace oil only if lost by leaks or removal due to replacement of parts. 
(See par 45.) 
Section XI 
Preventive Maintenance 
24. ORGANIZATIONAL MAINTENANCE (2ND ECHELON) 
o. Weekly. 
(1) Inspect condenser for foreign substances. (See par 29.) 
(2) Inspect evaporator. (See par 28.) 
19 fa. Monthly. 
(1) Lubricate according to instructions in Section X. 
(2) Inspect belt. (See par 33.) 
(3) Inspect motor commutator and clean il necessary. (See par 32.) 
Section XII 
Trouble Shooting 
25. VALVES AND GAGES 
a. General. In analyzing all problems of refrigeration it is important 
that the gages be installed to determine what operating conditions exist 
within the refrigeration system at the time of failure. By studying pres- 
sures indicated on the high and low side it is possible to determine the 
difficulty responsible for the improper operation of the machine. 
CHARGING PLUG 
FRONT SEAT 
-BACK SEAT 
-PACKING NUT 
-VALVE STEM 
CAP 
-VALVE STEM 
-GAUGE PLUG 
COMPRESSOR SERVICE VALVES 
DISCHARGE i SUCTION VALVE 
Figure 13. Compressor service valves. 
Med. Dept. No. 
()R2y062 
Nomenclature 
Valve, service, compressor 
fa. Compressor Service Valves. In order to properly analyze service 
problems, the mechanic must be familiar with the refrigeration cycle (fig 
3). The compressor is equipped with 2 valves—the one on the intake or 
suction side.of the compressor is called the “suction service valve” (fig 13), 
and the one on the discharge side of the compressor is called the “discharge 
service valve” (fig 13). Both valves are equipped with plugs and when the 
valve stems are turned in a counter clockwise direction termed the “back 
20 seating position,” the plug openings are closed. When the valve stems are 
turned in a clockwise direction termed the “front seating position,” the 
plug openings are open and the calves are closed or seated to the con- 
denser line or the suction line as the case may be. Any intermediate posi- 
tion of the stems other than seating permits the same pressure condition 
to exist in the gage connection as exists in the part to which the valves 
are connected. 
VALVE STEM 
VALVE STEM CAP 
PACKING NUT 
VALVE SEAT 
Figure 14. Liquid receiver valve. 
Med. Dept. No. 
qR2j2io 
Nomenclature 
Valve, receiver, liquid 
c. Liquid Receiver Valve. The liquid receiver is equipped with a 
shutoff valve (fig 14) that seats or closes in one position. When the valve 
stem is turned all the way in (clockwise) the valve is closed. When the 
stem is turned all the way out (counter clockwise) the valve is open. 
d. Reading the Gages. By installing the gages (see par 38) it is 
possible to read the actual pressure conditions that exist in either the 
low side or the high side (see Pressure Chart, fig i4A). Turn the valves 
clockwise 1 to 11/2 turns in order to get an actual reading condition. Be 
sure to back seat the valves before installing or removing the gages to 
prevent the loss of refrigerant. 
21 Air 
Temperature 
Head 
Pressure 
Suction 
Pressure 
80 Degrees 
i 15 Pounds 
25 Pounds 
9° 
160 “ 
25 
100 
172 
25 
1 10 
,78 “ 
25 “ 
1 10 “ 
190 
32 
Figure 1 4A. Pressure Temperature 
e. Moisture Precaution. The refrigeration system should never be 
opened under excess pressure or vacuum. Opening under pressure will 
cause the loss of refrigerant, and opening under a vacuum will draw air 
into the system. Air contains moisture which will freeze in the orifice of 
the expansion valve, resulting in service problems difficult to correct. 
(See par 46.) 
26. DIAGNOSIS OF REFRIGERATION TROUBLE 
a. Analysis of Symptoms. If the unit does not operate properly, a 
complete analysis of the system must be made before any adjustments, 
removal or replacement of parts are attempted. For explanation of re- 
frigeration cycle see fig 3. Before completing diagnosis consider all pos- 
sible causes to determine whether or not the correct diagnosis has been 
made. 
b. Altitude Effects. If the temperature in the storage compartment 
is too low, the altitude must be considered as a controlling factor. Al- 
though the control settings may be correct, the temperature will vary 
with the height above sea level. Estimate temperature on basis of control 
settings allowing 1 degree Fahrenheit drop in temperature for each 
thousand feet of altitude above sea level. (See par 48 d.) 
27. REFRIGERATION TROUBLE CHART 
The following trouble chart is for use by the personnel responsible 
for the 1st and 2nd echelon (operator and organizational) maintenance 
of this equipment. The chart represents troubles, possible causes, and 
their remedies. After analyzing the trouble and deciding upon the cause, 
apply specific remedies recommended. In servicing one part of the equip- 
ment be careful not to disturb the adjustment of other components 
of the unit. 
Condensing unit does not operate. 
Possible Causes 
(i) Extension cord plug not 
properly plugged in. 
Possible Remedies 
Plug in properly. 
22 Possible Causes Possible Remedies 
(2) Condensing unit motor See par 27 b. 
overload open. 
(3) Faulty refrigeration thermo- Refer to higher echelon, 
static or low pressure con- 
trols. 
(4) Expansion valve lost charge. Refer to higher echelon. 
(5) Plugged expansion valve. Refer to higher echelon. 
(6) Expansion valve strainer Refer to higher echelon, 
clogged. 
(7) Filter built within the Refer to higher echelon, 
dehydrator is plugged. 
(8) Loss of refrigerant charge. Refer to higher echelon. 
(9) Motor brushes worn. Replace motor brushes. 
(See par 31.) 
(10) Dirty commutator. Clean commutator. 
(See par 32.) 
b. Condensing unit motor overload protector switch cuts out. 
Possible Causes Possible Remedies 
(1) Motor field coils or arma- Refer to higher echelon, 
ture shorted. 
(2) Low voltage. Correct voltage is 110 AC, 60 
cycle, 1 phase. 
(3) Lack of lubrication to mo- Oil bearings once each month, 
tor bearings. (See par 22.) 
(4) Belt too tight. Adjust belt tension. (See par 
33-) 
(5) Leaking reed valves. Refer to higher echelon. 
c. Condensing unit operates but no refrigeration takes place. 
Possible Causes Possible Remedies 
(1) Belt slipping. Adjust belt tension. (See par 
33-) 
(2) Leaking reed valves. Refer to higher echelon. 
(3) Shortage of refrigerant. Refer to higher echelon. 
(4) Faulty expansion valve. Refer to higher echelon. 
(5) Air in condenser. Refer to higher echelon. 
23 Possible Causes Possible Remedies 
(6) Excessive refrigerant charge. Refer to higher echelon. 
(7) Inefficient compressor due Refer to higher echelon, 
to lack of lubrication. 
cf. Excessive head pressure. 
Possible Causes Possible Remedies 
(1) Air in the system. Refer to higher echelon. 
(2) Condenser blocked with Clean condenser. (See par 29.) 
dirt. 
(3) Excessive charge of refrig- Refer to higher echelon, 
erant. 
e. Condensing unit operates continuously. 
Possible Causes Possible Remedies 
(1) Shortage of refrigerant. Refer to higher echelon. 
(2) Leaking reed valves. Refer to higher echelon. 
(3) Excessive charge of refrig- Refer to higher echelon, 
erant. 
f. Suction line frosts back to compressor. 
Possible Causes Possible Remedies 
(1) Expansion valve out of ad- Refer to higher echelon, 
justment, passes too much 
refrigerant. 
(2) Leaking expansion valve Refer to higher echelon, 
does not close during off 
cycles. 
(3) Reed valve leaking, gas con- Refer to higher echelon, 
densing on low side during 
off cycles. 
(4) Refrigeration thermostatic Reset warmer-external adjust- 
control set too cold due to ment only. (See par 30.) 
altitude. 
(5) Expansion valve stuck open. Refer to higher echelon. 
g. Condensing unit short cycling 
Possible Causes Possible Remedies 
(1) Short of refrigerant. Refer to higher echelon. 
(2) Leaking reed valves. Refer to higher echelon. 
24 Possible Causes Possible Remedies 
(3) Motor overload protector See par 27 b. 
switch cycling on and off. 
(4) Suction line partially re- Refer to higher echelon, 
stricted due to kinked and 
collapsed tubing. 
(5) Dehydrator restricted. Refer to higher echelon. 
(6) Moisture in refrigeration Refer to higher echelon, 
system. 
(7) Low pressure control not set Refer to higher echelon, 
properly. 
(8) Expansion valve or expan- Refer to higher echelon, 
sion valve strainer restrict- 
ed. 
h. Refrigeration not uniform at evaporator plates. 
Possible Causes Possible Remedies 
(1) Leaking reed valves. Refer to higher echelon. 
(2) Controls out of adjustment. Refer to higher echelon. 
(3) Shortage of refrigerant. Refer to higher echelon. 
(4) Condensing unit operates Refer to higher echelon, 
continuously. 
(5) Expansion valve bulb loose Tighten bulb clamp. (See par 
in clamp on suction line. 34.) 
(6) Expansion valve does not Refer to higher echelon, 
close. 
Section XIII 
Maintenance Operations 
28. INSPECTING AND DEFROSTING EVAPORATOR 
a. Inspecting. Inspect the evaporator once each week to note if any 
frost or ice is accumulating. Under normal conditions, ice or frost should 
not accumulate; however, if it has, disconnect the electric service allowing 
frost to melt to insure free movement of the bottle racks. The defrost 
water can be drained through the machine compartment by opening the 
drain shutoff valve (fig 6, item 5). During the period required to remove 
the frost it will not be necessary to leave the door of the refrigerator 
compartment open. The cool temperature of the compartment is main- 
25 tained and the resultant temperature rise will not be beyond the safety 
margin if operation of the unit is resumed as soon as the cooling plates of 
the evaporator are clear. Always close the drain valve after defrosting. 
29. INSPECTING AND CLEANING CONDENSER 
To clean the condenser remove the rear machine compartment door 
and remove all foreign substances from the condenser. A small brush 
located on the right side of the machine compartment (fig 10, item i) is 
provided for this purpose. After using the brush be sure it is returned to 
the manual compartment. 
30. RESETTING REFRIGERATION THERMOSTATIC CONTROL 
This control (fig go) is equipped with a finger tip adjustment knob 
with limits to the user of 4 degrees Fahrenheit above and 4 degrees 
Fahrenheit below normal settings. The control knob (fig 30, item 3) is on 
the outside of the control. The adjustment knob is equipped with stops 
to maintain the limits of the setting. In making adjustments with the 
knob the temperature differential is constant. 
31. REPLACING MOTOR BRUSHES 
a. Removing. Worn motor brushes are indicated by sluggish start- 
ing, excessive arcing or failure to start the motor. To remove the motor 
brushes proceed as follows: 
(1) Disconnect the extension cord plug from the source of supply. 
(2) Remove the 4 nuts from the end plate bolts. 
(3) Remove the end plate by tapping around the flange until plate 
is free and can be removed from the shaft. 
(4) Lift brush holder spring and move to one side freeing brushes 
for removal. (BRUSHES MUST ALWAYS BE REPLACED 
IN SETS OF 4 - 2 PAIRS.) 
fa. Installing. To install the new brushes proceed as follows; 
(1) Insert the new brushes in the brush holder and bend the brush 
holder springs in position so they rest on top of the brushes. 
(2) Reinstall end plate on shaft by guiding the index plate through 
the slot in the brush holder. 
(3) Tap flange to secure the end plate to the motor frame and 
install nuts on the end plate bolts. Tighten the bolts uniformly 
by alternating from side to side. In tightening the bolts inspect 
the armature for free movement at intervals to assure proper 
alinement. Should the end plate fail to aline properly by tight- 
ening the bolts, tap lightly around the flange of the end plate 
until it fits snugly against the motor frame. 
(4) Reconnect the extension cord plug to the source of supply. 
26 32. INSPECTING AND CLEANING MOTOR COMMUTATOR 
The motor commutator will require cleaning due to accumulation of 
oil and dust. Excessive arcing and sluggish starting are the results of this 
condition. To clean the commutator proceed as follows: 
(1) Remove the inspection cover plate (item 1) on the end plate 
of the motor (fig 63). 
(2) With the motor in operation gently hold a piece of fine grade 
sandpaper against segments of the commutator long enough to 
remove the dirt accumulation. (DO NOT USE EMERY 
PAPER.) 
(3) Reinstall the inspection cover plate and secure with 2 screws. 
33. INSPECTING AND ADJUSTING BELT 
a. Adjusting. The belt should last an indefinite length of time if it 
has been operated under proper tension and the pulley is in proper aline- 
ment. Oil or lubricants of any kind should not be applied to the belt, and 
in the event that a slight stretching has occurred, the belt can easily be 
adjusted and the slack taken up. To adjust the belt tension proceed as 
follows: 
(1) The tension of the belt should permit a depression of about 
1/2 inch midway between pulleys as indicated in fig 43. 
(2) Loosen the 4 nuts at the base of the motor and slide the motor 
away from the compressor to increase the tension, and toward 
the compressor to decrease the tension. 
(3) Square the motor with the condensing unit base to secure 
proper alinement. 
(4) Tighten the 4 nuts at the base of the motor. 
b. Removing. To remove the belt proceed as follows: 
(1) Disconnect the extension cord plug from the source of supply. 
(2) Working from the front of the cabinet, grasp the compressor 
flywheel with the left hand at the upper portion of the outer 
edge. 
(3) With the right hand guide the belt toward the rear of the 
cabinet (away from the compressor). 
(4) With the left hand rotate the flywheel counter clockwise. 
(5) As the belt frees from the flywheel, slip it over the motor pulley 
and fan, and remove the belt from the unit compartment. 
c. Installing. To install the belt proceed as follows: 
(1) Place one loop of the belt over the fan and fit into the motor 
pulley. 
(2) Start the belt in the groove on top of the flywheel. 
27 (3) With the right hand guide the belt at the top of the flywheel, 
and with the left hand guide the belt into position rotating 
flywheel counter clockwise. 
(4) Adjust the belt for proper tension. (See par 33 a.) 
34. TIGHTENING THERMOSTATIC BULB CLAMP 
Secure the thermostatic bulb under the clamp at former location on 
the suction line between the center evaporator plates (fig 36) and tighten 
screws on clamp. 
28 PART FOUR 
AUXILIARY EQUIPMENT 
Section XIV 
General 
35. BLOOD REFRIGERATION UNIT GENERATOR 
Medical Department item No. 9960105, Unit, Blood 
Refrigeration, generator, is supplied with the refriger- 
ator as an auxiliary electrical power supply. Instruc- 
tions on the operation, maintenance and repair of the 
generator will be covered by a seperate Technical 
Manual on item No. 9960105. 
29 PART FIVE 
REPAIR INSTRUCTIONS 
Section XV 
General 
36. SCOPE 
These instructions are published for the information and guidance ol 
the maintenance personnel responsible for the third and higher echelons 
of maintenance of this equipment. They contain information on the 
maintenance of the equipment which is beyond the scope of the tools, 
equipment or supplies normally available to the using organizations. 
Section XVI 
Trouble Shooting 
37. REFRIGERATION TROUBLE CHART 
The following trouble chart is for use by the personnel responsible 
for third and higher echelon maintenance of this equipment. The chart 
represents troubles, possible causes, and their remedies. After analyzing 
the trouble and deciding upon the cause, apply specific remedies recom- 
mended. In servicing one part of the equipment be careful not to disturb 
the adjustment of other components of the unit. 
Condensing unit does not operate. 
Possible Causes Possible Remedies 
(1) Open circuit. Inspect for electrical continu- 
ity. See W iring Diagram, fig 5. 
(2) Condensing unit motor See par 37 b. 
overload open. 
(3) Faulty refrigeration thermo- Replace refrigeration thermo- 
static, or low pressure con- static, or low pressure control, 
trols. (See par 48.) 
(4) Expansion valve lost charge. Replace expansion valve. 
(See par 50.) 
(5) Plugged expansion valve. Blow out expansion valve. 
(See par 50.) 
(6) Expansion valve strainer Clean. (See par 50 g.) 
clogged. 
(7) f ilter built within the de- Replace dehydrator, 
hydrator is plugged. (See par 46 b.) 
30 Possible Causes Possible Remedies 
(8) Loss of refrigerant charge. Inspect for leak. (See par 40.) 
Repair leak. Recharge system. 
(See par 44 a.) 
(9) Motor brushes worn. Replace motor brushes. 
(See par 31.) 
(10) Dirty commutator. Clean commutator. 
(See par 32.) 
Condensing unit motor overload protector switch cuts out. 
Possible Causes Possible Remedies 
(1) Motor field coils or armature Replace motor field coils or 
shorted. armature. (See par 58 e and 
58 h.) 
(2) Low voltage. Correct voltage is 110 AC, 60 
cycle, 1 phase. 
(3) Lack of lubrication to motor Oil bearings once each month, 
bearings. (See par 22.) 
(4) Belt too tight. Adjust belt tension. 
(See par 33.) 
(5) Leaking reed valves. Replace reed valves. 
(See par 52.) 
Condensing unit operates but 
no refrigeration takes place. 
Possible Causes Possible Remedies 
(1) Belt slipping. Adjust belt tension. 
(See par 33.) 
(2) Leaking reed valves. Replace reed valves. 
(See par 52.) 
(3) Shortage of refrigerant. Add refrigerant. (See par 44.) 
(4) Faulty expansion valve. Replace expansion valve. 
(See par 50 f and 50 h.) 
(5) Air in condenser. Purge air from condenser and 
receiver. (See par 43.) 
(6) Excessive refrigerant charge. Purge out excessive charge. 
(7) Inefficient compressor due to Add refrigerant compressor 
lack of lubrication. lubricating oil (OR) to the 
compressor. (See par 45.) 
31 d. Excessive head pressure 
Possible Causes Possible Remedies 
(1) Air in the system. Purge air. (See par 43.) 
(2) Condenser blocked with dirt. Clean condenser. (See par 29.) 
(3) Excessive refrigerant charge. Purge out excessive charge. 
e. Condensing unit operates continuously. 
Possible Causes Possible Remedies 
(1) Shortage of refrigerant. Add refrigerant. (See par 44.) 
(2) Leaking reed valves. Replace reed valves. 
(See par 52.) 
(3) Excessive charge of Purge out excessive charge, 
refrigerant. 
f. Suction line frosts back to compressor. 
Possible Causes Possible Remedies 
(1) Expansion valve out of ad- Reset the expansion valve, 
justment, passes too much (See par 50 e.) 
refrigerant. 
(2) Leaking expansion valve— Replace expansion valve, 
does not close during off (See par 50 f and 50 h.) 
cycles. 
(3) Reed valve leaking, gas con- Replace reed valves, 
densing on low side during (See par 52.) 
off cycles. 
(4) Expansion valve stuck open. Remove moisture from system 
if present. See par 46 or re- 
place expansion valve if faulty. 
(See par 50 f.) 
g. Condensing unit short cycling. 
Possible Causes Possible Remedies 
(1) Short of refrigerant. Inspect for leaks and repair. 
See par'40. Add necessary re- 
frigerant. (See par 44 a.) 
(2) Leaking reed valves. Replace reed valves. 
(See par 52.) 
(3) Suction line partially re- Remove restriction or install 
stricted due to kinked and new suction line. Purge air. 
collapsed tubing. (See par 43.) 
32 Possible Causes Possible Remedies 
(4) Dehydrator restricted. Replace dehydrator. 
(See par 46 b.) 
(5) Moisture in refrigeration Remove moisture, 
system. (See par 46.) 
(6) Low pressure control not set Reset low pressure control, 
properly. (See par 48 k.) 
(7) Expansion valve or expan- Clean valve and strainer or re- 
sion valve strainer restricted. place valve. (See par 50.) 
h. Refrigeration not uniform at evaporator plates. 
Possible Causes Possible Remedies 
(1) Leaking reed valves. Replace reed valves. 
(See par 52.) 
(2) Controls out of adjustment. Adjust controls. (See par 48.) 
(3) Shortage of refrigerant. Add necessary refrigerant. 
(See par 44 a.) 
(4) Expansion valve does not Replace expansion valve, 
close. (See par 50 f and 50 h.) 
Section XVII 
Repair of Refrigeration System 
38. INSTALLING THE GAGES 
a. Installing the Compound Gage. The compound gage is calibrated 
from 30 inches of vacuum to 60 pounds per square inch pressure. To 
install the compound gage proceed as follows: (fig 15). 
(1) Locate the suction service valve (fig 15, item 3) attached to 
the head of the compressor and connected to the y8 inch suc- 
tion line. 
(2) Remove the valve stem cap. 
(3) Make certain that the valve is back seated. 
(4) Remove the lower pipe plug from the valve. 
(5) Connect the compound gage (fig 15, item 4) in the plug open- 
ing. (Screw in gage until gas tight.) 
(6) To read gage, open valve by turning stem 1 turn in a clock- 
wise direction. (Gage will now indicate pressure on the low side 
of the system.) 
33 Figure 15. Gages installed. 
Med. Dept. No 
T. qR2J2yO 
2. qR2yo62 
9. qR 27062 
4. 9/? 27252 
Nomenclature 
Gage, pressure 
Valve, service, compressor (discharge) 
Valve, service, compressor (suction) 
Gage, compound 
b. Installing the Pressure Gage. The pressure gage is calibrated from 
o to 300 pounds per square inch pressure. To install the gage on the 
compressor proceed as follows: 
(1) Locate discharge service valve (fig 15, item 2) attached to the 
head of the compressor and connected to the condenser. 
(2) Remove the valve stem cap. 
(3) Make certain that the valve is back seated. 
(4) Remove the lower pipe plug from the valve. 
(5) Connect the pressure gage (fig 15, item 1) in the plug opening. 
(Screw in gage until gas tight.) 
(6) To read gage, open valve by turning stem 1 turn in a clock- 
wise direction. (Gage will now indicate pressure on the high 
side of the system.) 
34 39. OPERATING THE LEAK DETECTOR 
a. Filling Leak Defector. The leak detector when filled and proper!) 
used will accurately detect the presence of Freon 12 refrigerant. To fill 
the leak detector proceed as follows: (fig 16). 
(1) Open the fuel tank by removing the base. Fill the tank with 
plain uncolored gasoline. Do not use alcohol or colored gaso- 
lines because these fuels may cause the detector to become 
clogged. The tank should be filled slowly in order to permit 
the wick in the tank to soak up the gasoline. Too rapid filling 
will reduce the amount of charge and materially cut down the 
burning time of the leak detector. Screw the base on tightly 
so the fuel will not leak out. 
(2) See that the regulating valve is shut by turning the regulating 
valve hand wheel all the way to the right. 
(3) Stand the detector upright and fill the priming cup about 1/9 
full with white gasoline and ignite. 
(4) After the priming fuel has burned out, open the regulating 
valve hand wheel slightly and touch a lighted match to a hole 
in the burner tube. 
(5) The vapor in the burner tube will ignite causing a hissing 
noise. Pressure and heat have been produced in the fuel tank 
by the heat and the burning gasoline in the priming cup. 
Gasoline from the fuel tank has vaporized under this heat and 
burns in the tube. 
Figure 16. Leak detector. 
Nomenclature Nomenclature 
/. Flame reducer 8. Burner tip 
2. Soldering point 9. Tip cleaner 
5. Sampling hose 10. Base 
_/. Regulating valve handWheel //. Fuel tank 
5. Valve wrench 12. Priming cup 
6. Brass plate 13. Burner tip 
7. Gasket 14. Sampling hose brass coupling 
13. Burner tube 
35 b. Using the Leak Detector. To use the leak detector proceed as 
follows: 
(1) Permit the detector to burn 2 or 3 minutes with a low flame. 
(2) Adjust the flame by regulating the valve hand wheel making 
the flame visible but not flaring out at the top and sides of the 
burner tube. 
(3) Pass the rubber end of the sampling hose over the refrigera- 
tion system (fig 17). When the hose comes in contact with a 
leaking part or connection, the Freon 12 refrigerant is drawn 
through the hose and turns the flame to a bright green. When 
the leaking refrigerant is no longer drawn into the sampling 
hose the flame resumes its blue color. The sampling hose then 
has passed beyond the leaking connection or part from which 
the refrigerant is escaping. 
(4) When testing for very small leaks, throttle the flame to pro- 
duce a more sensitive reaction. 
(5) To extinguish the detector, close the regulating valve by turn- 
ing hand wheel to a firm right seat and permit to cool. 
(6) Fhe detector will normally require filling after 45 minutes of 
operation. 
Figure 1 7. Testing for leaks. 
36 c. Cleaning the Defector. To clean the leak detector proceed as 
follows: (fig 16). 
(1) To clean the burner tip remove the tip from the detector using 
the wrench provided for this purpose. 
(2) Insert tip cleaner wire in large opening of tip and force through 
burner tip hole. (Tip cleaner, extra tip and gasket will be 
found in the bottom of the base under the round brass plate.) 
(3) Keep the holes in the burner tube clear of soot. 
(4) Make sure that the burner tube is screwed down tightly on 
the detector and there is no leakage around the regulating 
valve. 
d. Using Leak Defector as a Blow Torch. To use the leak detector 
as a blow torch proceed as follows: (fig 16). 
(1) Unscrew and remove the burner tube from the detector. 
(2) Remove the brass coupling that holds the sampling hose by 
slipping the coupling off the burner tube. 
(3) Reinstall the burner tube and screw it down tightly. The leak 
detector can now be used as a blow torch. 
(4) Fill the detector as outlined in par 39 a. 
(5) If a narrow flame is desired screw the flame reducer on the end 
of the burner tube. 
e. Using Leak Defector as a Soldering Iron. To use the leak detectoi 
as a soldering iron proceed as follows: 
(1) Screw the soldering point on the end of the burner tube. 
(2) Fill the detector as outlined in par 39 a. 
(3) Allow the detector to burn 3 minutes after lighting in order to 
heat the copper soldering point so that it will be hot enough 
for soldering. 
40. TESTING FOR LEAKS 
a. All refrigeration parts and connections must be gas tight to prevent 
the loss of the Freon t2 refrigerant from the system. Should the diagnosis 
indicate that a leak has developed, the system should be tested by the 
following procedure: 
(1) I nstall the gages. (See par 38.) 
(2) Disconnect the extension cord plug and permit the pressure 
on the low side of the system to build up to at least 25 pounds. 
(3) Fill the leak detector and place in operation as outlined in 
par 39 a. 
(4) Pass rubber end of the sampling hose over parts of the refriger- 
ation system including fittings, compressor shaft seal, and all 
37 connections. Note detector flame reaction to indicate the 
presence of a leak. (See par 39 b (3).) 
(5) Correct leaks found by repairing or replacing parts or con- 
nections. 
(6) Clear the air around the points where the leak was detected 
and retest for leaks after repairs have been made. 
(7) To test for leaks should the detector not be available, apply 
a soap and water lather to the fittings, compressor shaft seal 
and all connections. 
(8) After applying the lather, inspect closely for bubble or 
bubbling to indicate the presence of a leak. 
(9) All leaks must be corrected regardless of how small they 
may be. 
41. PUMPING DOWN THE SYSTEM 
a. In order to open the refrigeration system to the atmosphere for the 
removal or replacement of parts, it is imperative that the system be 
pumped down. This procedure isolates the entire refrigerant charge from 
the rest of the system and keeps it contained in the liquid receiver and 
the condenser. To pump down the system proceed as follows: 
(1) Install the gages. (See par 38.) 
(2) Locate the liquid receiver valve attached to the receiver (fig 
9, item 3). 
Figure 18. Blocking the low pressure control. 
i. Wood block 
38 (3) Remove the valve stem cap. 
(4) Close the valve. 
(5) Operate the compressor continuously until the pressure indi- 
cated on the compound gage is zero. IT WILL BE NECES- 
SARY TO BLOCK THE LOW PRESSURE CONTROL 
CONTACT POINTS BY REMOVING THE CONTROL 
COVER PLATE AND WEDGING A PIECE OF WOOD 
BETWEEN THE INNER CASE OF THE CONTROL AND 
THE CONTACT ARM AS INDICATED IN FIG 18. 
(6) Permit compressor to stop. TTe pressure on the compound 
gage will rise. 
(7) Operate the compressor intermittently until the pressure is 
stationary at 1 pound when the compressor is not operating. 
(8) Front seat the discharge service valve. 
(9) Front seat the suction service valve. 
(10) The system is now pumped down and the refrigerant is iso- 
lated in the liquid receiver tank and the condenser. 
42. BALANCING THE PRESSURE FOR COMPRESSOR REPAIRS 
a. To open the compressor body to the atmosphere the refrigerant 
in the compressor body must be evacuated and the pressure balanced. To 
balance the pressure proceed as follows: 
(1) Install the gages. (See par 38.) 
(2) Locate the suction service valve attached to the compressor 
(fig »5)- 
(3) Remove the valve stem cap. 
(4) Front seat the valve. 
(5) Permit the compressor to operate until the pressure indicated 
on the compound gage is o. It will be necessary to manually 
close the low pressure control contact points by removing the 
control cover plate and manually depressing the lever as in- 
dicated in fig 19. 
(6) Disconnect the extension cord plug from the source of supply. 
(7) Remove the valve stem cap and front seat the discharge service 
valve (fig 15, item 2). 
(8) The following services can now be performed without remov- 
ing the compressor body from the unit compartment: 
(a) Replace or repair valve plate assembly. 
(b) Inspect oil level. 
(c) Add oil to the compressor. 
(d) Remove suction line strainer for cleaning. 
39 Figure 1 9. Manually closing low pressure control, 
43. PURGING AIR FROM THE SYSTEM 
a. Purging the Compressor. After the compressor has been opened 
to the atmosphere, a small amount of air will be trapped within when 
reassembled. This air must be removed from the compressor. To purge 
the compressor proceed as follows: 
(1) With the suction and discharge service valves front seated, 
remove the pressure gage from the discharge service valve 
(fig *5)- 
(2) Turn the suction service valve 1/2 turn counter clockwise. 
(3) Rotate the compressor flywheel by hand 2 complete revolu- 
tions. This action will purge the trapped air from the com- 
pressor through the gage opening in the discharge service 
valve out into the atmosphere. 
b. Purging the Low Side of the System. Should the low side of the 
system be opened to the atmosphere, the air trapped within the low side 
during reassembling must be removed (see Chart, fig 4, for explanation of 
parts on low side). To purge the low side of the system proceed as follows: 
(1) Install the compound gage. (See par 38.) 
(2) Front seat the discharge service valve. 
(3) Remove pressure gage or gage plug. 
(4) Block the low pressure control contact points by removing 
the control cover plate and wedging a piece of wood between 
40 the inner case of the control and the contact arm as indicated 
in fig 18. 
(5) Permit the unit to operate for a period of 5 minutes under at 
least a 20-inch vacuum. During this period the trapped air in 
the low side of the system is being discharged through the 
gage plug opening in the discharge service valve to the at- 
mosphere. 
(6) After 5 minutes of operation reinstall the gage plugs on the 
discharge service valve while the unit is still operating. 
(7) Disconnect the extension cord plug from the source of supply. 
(8) Remove the wooden wedge from the low pressure control and 
reinstall the control cover. 
(9) Back seat both the discharge and the suction service valves. 
(10) Remove the compound gage and reinstall the gage plug and 
valve caps. 
(11) Open the liquid receiver valve, and replace valve cap. 
(12) Reconnect the extension cord plug to the source of supply. 
The unit is now in operation. 
c. Purging the Entire Refrigeration System. Should repairs necessi- 
tate the removal of the entire charge of refrigerant, the air trapped within 
the system must be removed after the installation of the new parts. This 
is accomplished by purging the entire refrigeration system from the dis- 
charge service valve through the condenser, liquid receiver, evaporator, 
and compressor. To purge the entire refrigeration system proceed as 
follows: 
(1) Remove the valve stem cap and open the liquid receiver valve 
to a firm back seat (fig 9). 
(2) Remove the valve stem cap and back seat the suction service 
valve (fig 15). 
(3) Remove the lower gage plug and install the compound gage 
(screw in gas tight). 
(4) Turn the suction service valve 2 complete turns (clockwise). 
(5) Front seat the discharge service valve. 
(6) Remove the lower gage plug. 
(7) Allow the compressor to operate continuously until the suc- 
tion pressure indicates 20 inches of vacuum on the compound 
gage. IT WILL BE NECESSARY TO BLOCK THE LOW 
PRESSURE CONTROL CONTACT POINTS BY REMOV- 
ING THE CONTROL COVER PLATE AND WEDGING 
A PIECE OF WOOD BETWEEN THE INNER CASE OF 
THE CONTROL AND THE CONTACT ARM AS IN- 
DICATED IN FIG 18. 
41 (8) With a 20-inch vacuum maintained permit the unit to operate 
for a period of 20 minutes, assuring the removal of all air 
from the system. During this period, the trapped ah in the 
system is being discharged through the gage plug opening in 
the discharge service valve to the atmosphere. 
(9) After operating the unit for the time specified above, reinstall 
the gage plug in the discharge service valve, and at the same 
time, remove the wooden wedge from the low pressure control. 
With the wedge removed, the deep vacuum now maintained 
will allow the contact points on the low pressure control to 
open, breaking the electrical circuit to the motor stopping 
the unit. 
(10) Back seat both the suction and discharge service valves. 
(11) Reinstall cover on low pressure control. 
(12) Remove upper gage plug from the suction service valve, and 
charge the system with Freon 12 refrigerant as outlined in 
par 44- 
44. ADDING AND REMOVING REFRIGERANT FROM THE SYSTEM 
a. Adding Refrigerant to the System. Refrigerant lost by leaks or 
by the replacement of parts must be restored to the system to maintain 
proper refrigeration. To add refrigerant proceed as follows: (fig 20). 
Figure 20. Adding refrigerant to system. 
42 (1) Install gages. (See par 38.) 
(2) Back seat the suction service valve and remove the upper gage 
plug. 
(3) Install a i/g inch pipe to a \/A inch flare connector in the plug 
opening. 
(4) Connect a 14 inch charging line from the connector to a re- 
frigerant supply cylinder. Leave the 14 inch flare nut attached 
to the connector loosely coupled. 
(5) Place supply cylinder in a pail of hot water keeping cylinder 
in an upright position. 
(6) Purge the charging line by slightly opening and immediately 
closing the valve on the supply cylinder. 
(7) Tighten 14 inch flare nut attached to the connector. 
(8) Turn the suction service valve 2 complete revolutions (clock- 
wise). 
(9) Open the supply cylinder valve and permit unit to cycle until 
the correct amount of refrigerant has been added. DET ER- 
MINE THE NORMAL CHARGE OF REFRIGERANT 
FROM THE PRESSURE TEMPERATURE CHART. (FIG 
14A). A FULL CHARGE OF FREON 12 REFRIGERANT 
IS 21/2 POUNDS. 
(10) After the correct amount has been added, close the valve on 
the supply cylinder and back seat the suction and discharge 
service valves. Remove the charging line, connector, and gages. 
Reinstall gage plugs and valve caps. 
b. Removing Refrigerant from the System. To remove or replace 
any parts on the high side of the refrigeration system (fig 4), the com- 
plete charge of refrigeration must be removed from the system into an 
empty service cylinder. (Fig 21.) To remove the refrigerant proceed as 
follows: 
(1) Pump down the system. (See par 41.) 
(2) Unscrew the 14 inch flare nut on the liquid line valve con- 
nected to the top of the dehydrator and remove the liquid line 
(fig 2 1). 
(3) Connect a \/A inch discharge line to the dehydrator and con- 
nect the opposite end of the discharge line to the service 
cylinder leaving this connection loosely coupled. 
(4) Purge the discharge line from the dehydrator to the service 
cylinder by slightly opening and immediately closing the 
liquid receiver valve. 
43 (5) Tighten the lutings on the cylinder and open cylinder valve. 
(6) Open the liquid receiver valve. 
(7) Place the service cylinder in a pail of cold water to lower its 
temperature below that of the liquid receiver tank. 
(8) Allow 10 minutes for the transfer of the refrigerant, then close 
the liquid receiver valve and remove the charging line from 
the dehydrator. 
Figure 21. Removing refrigerant from system. 
Figure 22. Inspecting oil level. 
44 45. ADDING OIL TO THE COMPRESSOR 
a. It is seldom necessary to add oil to the compressor since the oil is 
in a closed system at a temperature not inducive to carbonization. Only 
replace oil if lost through leaks or replacement of parts. To add oil to the 
compressor proceed as follows: (fig 23). 
Figure 23. Adding oil to compressor. 
(1) Balance the pressure for compressor repairs as outlined in 
par 42. 
(2) Remove the compound gage and install the gage plug. 
(3) Remove the oil plug and inspect oil level as indicated on the 
gage rod (fig 22). THE OIL MUST COME UP TO THE 
TOP MARK ON THE GAGE ROD. IF THE OIL LEVEL 
IS BELOW THIS MARK THE COMPRESSOR IS SHORT 
OF OIL. 
45 (4) Insert a funnel in the oil [dug opening and add the required 
amount of Freon 12 refrigerant oil to bring the level up to the 
top mark on the gage rod. 
(5) Remove the funnel and reinstall the oil plug. 
(6) Purge the compressor. (See par 43 a.) 
(7) Back seat the suction and discharge set vice valves. 
(8) Remove tlie pressure gage and install the gage plug and valve 
stem caps. 
Figure 24. Removing the dehydrator. 
Med. Dept. No, 
I. ()li2~ 222 
Nomenclature 
Dehydrator 
46. SERVICING THE DEHYDRATOR 
a. Removing Moisture from the System. In order to properly cor- 
rect a moisture condition it is necessary to have a dehydrator installed 
in the liquid line between the liquid receiver tank and the expansion 
valve. Therefore, a dehydrator is installed on this equipment when it 
leaves the factory to take care of any moisture that may enter the system 
due to opening operations such as installation of gages, etc. Even though 
this precaution is taken by the designer and manufacturer, the capacity 
of this dehydrator is limited. 
46 (1) Should moisture freeze in the expansion valve restiicting the 
flow of refrigerant, it may be necessary to apply heat to the ex- 
pansion valve intermittently until the moisture that is causing 
the trouble has been carried throughout the system in its nor- 
mal cycle, and returned to the dehydrator where it will be 
absorbed. 
(2) Should the system be exposed to more moisture than the 
capacity of the dehydrator is capable of absorbing, it will be 
necessary to replace the dehydrator. 
NOTE: UNDER EXTREME MOISTURE CONDITIONS IT MAY 
BE NECESSARY TO REPLACE THE DEHYDRATOR (FIG 24) 
MORE THAN ONCE TO THOROUGHLY FREE THE SYSTEM 
FROM MOISTURE. 
b. Replacing the Dehydrator. To replace the dehydrator proceed as 
follows: 
(1) Pump down the system. (See par 41.) 
(2) Remove the liquid line from the top of the dehydrator by 
unscrewing the 14 inch flare nut. 
(3) Remove the dehydrator from the liquid receiver valve by un- 
screwing the dehydrator with a wrench (fig 24). 
(4) Screw on new dehydrator to the liquid receiver valve making 
certain that the copper washer is inserted in the female fitting 
of the dehydrator to form a gas tight connection. 
(5) Reconnect the liquid line 14 inch flare nut to the male fitting 
on top of the dehydrator. 
(6) Purge the low side of the refrigeration system. (See par 43 b.) 
(7) Test for leaks. (See par 40.) 
47. SERVICING THE EVAPORATOR 
a. Removing the Evaporator. Direct service to the evaporator will 
be seldom, if ever, required unless the evaporator plates have been punc- 
tured by misuse or accident. Should this occur, the evaporator must be 
removed and, if possible, repaired; otherwise a new evaporator must be 
installed. The evaporator must also be removed from the cabinet to gain 
access for the removal of the heater element and controls. To remove 
the evaporator proceed as follows: 
(1) Pump down the system. (See par 41.) 
(2) Remove bottle racks and shelves from the evaporator. 
(3) Remove the tube channel cover plate at rear of cabinet. 
(4) Remove the sealing compound from the tube hole. 
(5) Remove tape from the lines and cable in tube channel. 
47 Figure 25. Unsoldering suction line union. 
Med. Dept. No. 
I. 9R27240 
Nomenclature 
Coupling, line, suction 
Figure 26. Removing evaporator. 
48 (6) Disconnect the liquid line by unscrewing the 14 inch flare nut 
on top of the dehydrator. 
(7) Apply torch to the soldered fitting on the suction line union 
and disconnect union (fig 25, item 1). 
(8) Remove the bends from the liquid and suction lines, and pull 
lines through lower tube channel opening. 
(9) Plug the open ends of the lines with clean dry cloth to pre- 
vent moisture and foreign substances from entering. 
Figure 27. Evaporator removed. 
(10) Remove the 8 supporting screws, SR01120 (fig 34, item 2), 
from the evaporator (4 in each end plate). Spacers, 9R27052 
(fig 34, item 7), will drop as the screws are removed. 
(1 1) fiend suction and liquid lines with a long sweep (so as not to 
kink) sufficient to permit the lines to pass through the tube 
hole in the cabinet. 
(12) Slide the evaporator forward from the storage compartment, 
and at the same time guide the lines through the tube hole 
permitting the evaporator and lines to be removed as an as- 
sembly (fig 26). 
49 b. Installing the Evaporator. To install the evaporator proceed as 
follows: 
(1) Slide the evaporator with lines attached into the storage com- 
partment guiding the lines through the tube hole in rear ol 
cabinet. 
(2) Replace the 8 supporting screws through the end plates and 
spacers by using a soft wire fitted around the spacers (fig 28). 
Withdraw the wire after the spacers are held in position by 
the supporting screws. 
Figure 28. Installing evaporator support spacers. 
(3) Shape the suction and liquid line tubing to the contour of the 
tube channel. 
(4) Bend lines through lower tube channel opening. Remove 
plugs from the lines and resolder the suction line union and 
connect the liquid line to the dehydrator. 
(5) Retape lines and cable in the tube channel. 
(6) Soften the sealing compound in hot water and work into the 
tube hole, sealing the hole sufficiently to prevent heat leakage. 
(7) Reinstall the tube channel cover plate with 10 screws. 
(8) Open all 3 valves on condensing unit. 
50 (9) Test for leaks. (See par 40.) 
(10) Reinstall the shelves and bottle racks. 
48. CONTROLS 
a. Explanation of Control System. Since all controls have been ac- 
curately set at the factory be sure the control is at fault before attempt- 
ing to adjust or correct its setting. DO NOT ADJUST OR CHANGE 
THE CONTROL SETTINGS UNTIL THE CONDENSING UNIT 
HAS COMPLETED AT LEAST 3 CYCLES. The operation of all con- 
trols may be observed by removing their inspection cover. On the low 
pressure control the cover is snapped into position at one point and 
hinged at the opposite side. On the refrigeration and heater thermostatic 
controls the covers are held in place by screws. 
fa. The refrigeration thermostatic control, 9R27190 (fig 29, item 4), 
and the low pressure control, 9R27202 (fig 29, item 3), are wired in series 
(fig 5). If the condensing unit does not operate when the storage compart- 
Figore 29. Controls. 
Med. Dept. No. 
1. pRiyojh 
2. 
3. (jR.2y202 
4. pRiyrgo 
5- 
Nomenclature 
Control, thermostatic, heater 
Terminal screws 
Control, pressure, loiu 
Control, thermostatic, refrigeration 
Terminal screws 
ment temperature has risen to a point where the controls are set to cut 
in, inspect both controls to see which one is holding open. Since the 
relative temperature pressure setting is lower than the temperature con- 
51 trol setting, the low pressure control should not operate, but remain 
closed under normal conditions. The refrigeration thermostatic control 
actually controls the temperature within the storage compartment for 
refrigeration temperature condition, and is designed to operate the con- 
densing unit motor. Contacts close on temperature rise and open on tem- 
perature drop. 
Figure 30. Refrigeration thermostatic control. 
Nomenclature 
1. Differential adjustment 
2. Set screw 
3. Control knob 
This control is supplied with a cross, fin type bulb mounted in the 
storage compartment (fig 34, item 4) and based on air temperature differ- 
ential of 1 degree Fahrenheit rise per minute. This should be taken into 
consideration when making any change in adjustment or noting reaction. 
c. NO ATTEMPT SHOULD BE MADE TO SET OR ADJ UST THE 
THERMOSTATIC CONTROLS TO AGREE WITH THE INDI- 
CATING DIAL THERMOMETER OF THE REERIGERATOR. 
Each time the door is opened the bulb is swung into the outside 
52 temperature. It is not practical to consider the condition indicated on the 
dial of the thermometer until the door has remained closed for a period of 
time sufficient to permit the equalization of the bulb to the temperature 
surrounding it. The temperature to which the thermostatic controls react 
are temperatures surrounding the cross fin bulbs mounted at the rear of 
the compartment. If an attempt is made to adjust the thermostatic con- 
trols in the field, it would he necessary to place an accurate thermometer 
at the same point of the fin bulbs. The object of the thermometer on the 
door only indicates that the condensing unit is actually performing as it 
should. THE THERMOMETER IS NOT TO BE USED AS A CRIT- 
ICAL TEMPERATURE ADJUSTMENT FOR THE CONT ROLS. 
d. Altitude Adjustments. Changes in altitude affect the settings of 
the controls used in this refrigerator. Atmospheric pressure drops approxi- 
mately i inc h of mercury or ]/2 pound per square inch for each i thousand 
feet increase in altitude. Controls of the totally enclosed charged element 
type such as the refrigeration and heater thermostatic controls when 
calibrated in one certain altitude must be corrected if they are to be 
used at any other altitude. T he settings must be raised if the controls are 
to be used at a higher altitude, and the settings must be lowered if the 
controls are to be used at a lower altitude. For example, these controls 
were set originally at an altitude of 600 feet. If the refrigerator cabinet 
is installed and used at a location where the altitude is 4,600 feet, the 
settings of the refrigeration and heater thermostatic controls, must be 
raised approximately 1 degree for each 1,000 feet of altitude increase. 
In this case, the altitude increase was 4,000 feet; therefore, the control 
settings will have to be raised approximately 4 degrees in order to com- 
pensate for the altitude increase. The low pressure control setting must 
also be raised ]/2 pound for each 1,000 feet of altitude increase. There- 
fore, in the example cited above, the pressure setting must be raised 2 
pounds to compensate for the 4,000 feet altitude increase. 
e. Adjusting the Refrigeration Thermostatic Control. This control 
(fig 30) is equipped with a finger tip adjustment knob with limits to the 
user of 4 degrees Fahrenheit above and 4 degrees Fahrenheit below 
normal settings. The control knob (fig 30, item 3) is on the outside of the 
control. The adjustment knob is equipped with stops to maintain the 
limits of the setting. In making adjustments with the knob the tempera- 
ture differential is constant. 
(1) RANGE ADJUSTMENT. Should the limits of the refrigera- 
tion thermostatic control knob not permit the setting required, 
it will be necessary to release the set screw in the knob (fig 30, 
item 2) to obtain a greater range. 
(2) DIFFERENTIAE ADJUSTMENT. Should the differential of 
the refrigeration thermostatic control require adjustment, re- 
move the side cover and adjust by means of a screw driver at the 
point indicated (fig 30, item 1). 
53 f. Removing the Refrigeration Thermostatic Control. If after 
proper diagnosis the control is faulty and must be replaced, remove the 
control as follows: 
(1) Remove the evaporator from the cabinet. (See par 47 a.) 
(2) Remove clamps from upper arched bulb at rear of the storage 
compartment (fig 34, item 5). 
(3) Disconnect the extension cord plug from the source of supply. 
(4) Remove cover from refrigeration thermostatic control (fig 29) 
by loosening the screws on both sides of the cover. 
(5) Disconnect the wiring at terminal screws (fig 29, item 5), un- 
tape and unsolder splice. Remove cables. 
(6) Remove the 2 screws from the supporting bracket of control. 
(7) Remove the tube channel cover plate at rear of cabinet (fig 7). 
(Plate secured to cabinet by 10 screws.) 
(8) Straighten finned bulb in storage compartment sufficient to 
allow passing through opening at rear of cabinet (fig 31). 
Figure 31. Removing control bulb. 
54 (9) Loosen clamps securing capillary lines and wiring in unit 
compartment and remove tape (fig 29). 
(10) Pass finned bulb through opening at rear of storage compart- 
ment (fig 31). Release capillary line from tube channel and 
clamps. Lift clear the entire assembly through front of the 
unit compartment. 
the control proceed as follows: 
g. Installing the Refrigeration Thermostatic Control. To install 
(1) Place finned bulb through opening at bottom of tube channel 
and opening through cabinet at rear of storage compartment 
(figs1)- 
(2) Shape capillary line and clamp bulb in an arched position 
above heater bulb on rear wall of storage compartment (fig 
34, item 4). 
(3) Shape capillary line in tube channel and unit compartment to 
the contour of the wiring cable under the clamps. Retape lines 
and cable (fig 7). 
(4) Secure control by 2 screws through bracket to frame of cabinet. 
(5) Install and connect cables to control in accordance with wiring 
diagram (fig 5). Solder and tape spliced connection. 
(6) Attach cover of control and tighten screws on both sides. 
(7) Reinstall evaporator. (See par 47 b.) 
mostatic control, 9R27056 (fig 29, item 1), is very similar to the refrigera- 
tion thermostatic control except that the contacts open on temperature 
rise and close on temperature drop. The limits of the adjusting knob are 
the same as on the refrigeration thermostatic control, namely, 4 degrees 
Fahrenheit above and 4 degrees Fahrenheit below, or a total adjustment 
of 8 degrees Fahrenheit. 
h. Adjusting the Heater Thermostatic Control. The heater ther- 
(1) RANGE AD JUSTMENT. Like the refrigeration thermostatic 
control, the range on the heater thermostatic control has been 
established within the limits of the adjusting knob. 
(2) DIFFERENTIAL ADJUSTMENT. The differential in the 
heater thermostatic control is non-adjustable. It is set at a pre- 
determined setting of 7 degrees Fahrenheit at the time of manu- 
facture. 
nosis the control is faulty and must be replaced, remove the control as 
follows: 
i. Removing the Heater Thermostatic Control. If after proper diag- 
(2) Remove clamps from lower straight bulb at rear of storage 
compartment (fig 34, item 3). 
(1) Remove evaporator from cabinet.[(See par 47 a.) 
55 Figure 32. Heater thermostatic control 
(3) Disconnect extension cord plug from source of supply 
(4) Remove cover from heater thermostatic control by loosening 
screws on both sides of cover (fig 32). 
(5) Disconnect the wiring at terminal screws, untape and unsolder 
splice. Remove cable. 
(6) Remove the 2 screws from the supporting bracket of control 
(7) Remove the tube channel cover plate at rear of cabinet. (Plate 
secured to cabinet by 10 screws.) (fig 7). 
(8) Straighten finned bulb in storage compartment sufficient to 
allow passing through opening at rear of cabinet (fig 31). 
(9) Loosen clamps securing capillary lines and wiring in unit com 
partment and remove tape (fig 29). 
(10) Pass finned bulb through opening at rear of storage compart- 
ment (fig 31). Release capillary line from tube channel and 
clamps. Lift clear the entire assembly through front of the unit 
compartment. 
56 trol proceed as follows: 
/. Installing the Heater Thermostatic Control. To install the con- 
(i) Place finned bulb through opening at bottom of tube channel 
and opening through cabinet at rear of storage compartment 
(fig 31)- 
(2) Shape capillary line and clamp bulb below the refrigeration 
thermostatic bulb on rear wall of storage compartment (fig 34, 
item 3). 
(3) Shape capillary line in tube channel and unit compartment to 
the contour of the wiring cable under the clamps. Retape lines 
and cable (fig 7). 
(4) Secure control by 2 screws through bracket to frame of cabinet. 
(5) Install and connect cables to control in accordance with wiring 
diagram (fig 5). Solder and tape spliced connection. 
(6) Attach cover of control and tighten screws on both sides. 
(7) Reinstall evaporator. (See par 47 b.) 
k. Adjusting the Low Pressure Control. The low pressure control, 
9R27202 (fig 29, item 3), is designed to automatically control the con- 
densing unit motor in series with the refrigeration thermostatic control. 
Contacts close on pressure rise and open on pressure drop. 
Figure 33. Low pressure control. 
1. Adjusting screw lock 
2. Adjusting screiv 
4. Rubber sealing plug 
Nomenclature 
4. Differential adjusting screiv 
5. Cable lead terminals 
57 The purpose of this control is to prevent the temperature dropping 
below the freezing point of whole blood should the refrigeration thermo- 
static control fail to open. The normal setting of this control is to cut in 
at 27 pounds pressure, and cut out at 15 pounds pressure. Before making 
any change in the setting of this control take into consideration that 
changing the adjustment may cause the condensing unit to operate from 
the low pressure control instead of the temperature control which is not 
the intention of the designer as the low pressure control is intended only 
as an emergency cut-out. 
(1) CUT-IN AND CUT OUT ADJUSTMENT. To change both 
the cut-in and cut-out point of the low pressure control, install 
the gages. (See par 38.) Remove the adjusting screw lock (fig 
33, item 1) which is attached to the adjusting screw (item 2). To 
raise the temperature setting, turn the spring adjusting screw 
to the right (clockwise). To lower the temperature setting, turn 
the adjusting screw in a counter clockwise direction or to the 
left. In making this adjustment you will be lowering or raising 
both the cut-in point and the cut-out point as the case may be. 
In setting the control the cut-in point must be established 
first. After the adjustment has been made replace the lock and 
screw to prevent adjusting screw from vibrating from its new 
position. 
(2) DIFFERENTIAL ADJUSTMENT. To change the cut-in 
point only, or to change the differential setting remove the 
rubber sealing plug (fig 33, item 3). Insert small screw driver 
through the hole from which the rubber plug was removed and 
engage the screw driver in the slotted differential adjusting 
screw (fig 33, item 4). 
To lower the cut-in point only, turn the adjusting screw to the right or 
clockwise. To raise the cut-in point or widen the differential, turn the 
adjusting screw to the left or counter clockwise. After the adjustment has 
been made, reinsert the sealing plug in the adjustment hole. 
WARNING: THE EXTENSION CORD PLUG MUST BE DIS- 
CONNECTED FROM THE SOURCE OF SUPPLY BEFORE AT- 
TEMPTING TO MAKE ANY ADJUSTMENTS ON THE LOW 
PRESSURE CONTROL. THIS APPLIES PARTICULARLY TO 
THE DIFFERENTIAL ADJUSTMENT SINCE THE CONTACTS 
ARE ELECTRICALLY COMMON TO THE ADJUSTING SCREWS 
ON WHICH YOU ARE PLACING YOUR SCREW DRIVER. 
I. Removing the Low Pressure Control. If after proper diagnosis 
the control is faulty and must be replaced, remove the control as follows: 
(fig 33)- 
(1) Pump down the system. (See par 41.) 
(2) Disconnect the extension cord plug from the source of supply. 
58 (3) Disconnect the 14 inch flare nut connection on top of the 
control. 
(4) Remove the 2 screws supporting the control bracket with cable 
attached and lift control to the front of the cabinet. 
(5) Remove the cover plate from the control. 
(6) Disconnect the cable leads at the control terminals (fig 33, 
item 5). 
(7) Remove the cable from the control 
(8) The control is now free and can be removed from the unit 
compartment. 
m. Installing the Low Pressure Control. To install the low pressure 
control proceed as follows: (fig 33). 
(1) Install cable into control box and connect the cable leads to the 
control terminals (fig 33, item 5). 
(2) Attach cover plate to the control. 
(3) Place control into position and secure to the unit base by 2 
screws through the mounting bracket. 
(4) Loosely connect the (4 inch flare nut connection on the top of 
the control (DO NOT TIGHTEN NUT GAS TIGHT). 
(5) Purge the 14 inch control line by slightly opening and im- 
mediately closing the liquid receiver valve. This action will 
allow a small amount of refrigerant gas to pass through the 
14 inch control line and force any trapped air out through the 
loosely connected 14 inch flare nut. 
(6) Tighten the 14 inch flare nut connection on top of the control 
gas tight. 
(7) Open the liquid receiver valve to a firm left seat and test for 
leaks. (See par 40.) 
(8) Open the suction service valve and the discharge service valve 
to a back seating position. 
(9) Reinstall the 3 valve stem caps. 
(10) Remove the gages and reinstall the gage plugs. 
(11) Reconnect the extension cord plug to the source of supply. 
49. SERVICING THE HEATER UNIT 
a. Removing the Heater. If after a diagnosis the heater unit is found 
to be at fault, inspect the cable leads making sure they are securely fas- 
tened to the heater terminal posts. Should the terminals be securely 
fastened and the heater unit still fails to operate, the heater must be 
replaced. To replace the heater unit proceed as follows: 
59 (i) Remove the evaporator, (See par 47 a.) 
(2) Disconnect the extension cord plug from the source of supply. 
(3) Remove the 2 screws, SR00892 (fig 34, item 1), supporting the 
(4) Remove 3 screws, SR00141 (fig 35, item 10), from the clamps. 
9R27246 (fig 35, item 8), supporting the heater element. 
heater unit assembly at the rear of the cabinet. 
(5) Disconnect the cable leads from the terminals (fig 35, item (i) 
Figure 34. Heater unit and control bulbs installed. 
Med. Dept. No. 
1. SRoo8p2 
2. SR0II20 
3- 
4- 
5. 9R27058 
6. pR2~o5j 
7. 9.R27052 
Nomenclature 
Screw, 10 x s/8 inch sheet metal R.H. “Z” 
Screw, 14-20 x 1 inch hex. hd. cap 
Heater thermostatic control bulb 
Refrigeration thermostatic control bulb 
Clamp, thermostatic, controls 
Element, heating 
Spacer, support, evaporator 
60 b. Installing the Heater. To install the heater unit proceed as fol- 
lows: 
(i) Connect the cable leads to the terminals of the heating unit 
(fig 35, item 6). 
(2) Place small mica insulator between guard and terminals and 
aline holes (fig 35, item 5). 
(3) Fasten heater element to guard, 9R27244 (fig 35, item 9), by 
means of 3 clamps, screws and nuts as shown in fig 35. 
(4) Place into position at the rear of the cabinet alining all holes 
to conform with the holes in the rear of the compartment so 
as to permit the assembly of the asbestos pad (item 2) mica 
insulator (item 4) and guard (item 9) in sequence as shown in 
fig 35- 
(5) Secure the assembly by 2 screws (fig 34, item 1) through the 
guard and components to the rear wall of the cabinet. 
Figure 35. Heater unit assembly. 
Med. Dept. No. 
1. PR27034 
2. gR 23232 
3. SRoo8g2 
3. gR2"j26o 
5. gR.23238 
6. 
7. SR00330 
8. gR.2y2j6 
g. gR2j244 
10. SR00141 
Nomenclature 
Element, healing 
Pad, unit, heating 
Screxo, 10 x y8 inch sheet metal R.H. “Z 
Insulator, heating unit and j)ad 
Insulator, heating unit and guard 
Terminal nuts 
Nut, #10-32 hex. much. scr. 
Clamp, unit, heating 
Guard, unit, heating 
Screw, #10-32 x 3/16 R.H. much. 
61 50. SERVICING THE THERMOSTATIC EXPANSION VALVE 
a. The thermostatic expansion valve is the control or metering device 
that reduces the pressure of the refrigerant permitting it to expand as it 
enters the evaporator. In order to perform its function the orifice in the 
expansion valve is very small. The most common service problem of the 
valve is the restricting of the orifice by either foreign material carried 
with the refrigerant or the freezing of moisture. 
Figure 36. Thermostatic expansion valve installed. 
Med. Dept. No. 
/. 9R27188 
2, 
5. (jR.27220 
4. 91127224 
Nomenclature 
Valve, expansion, thermostatic 
Thermostatic bulb clamp screzvs 
Nut, flare, 14 inch 
Nut, flare, 3/$ inch 
b. To minimize these service problems the refrigerator is equipped 
with a dehydrator which under normal conditions will prevent moisture 
from restricting the valve as well as filtering out foreign substances from 
the refrigerant. 
c. The most common indication of either moisture or dirt restricting 
the valve will be short cycling of the unit or failure to operate due to the 
pressure dropping below the cut-out point of the low pressure control. 
Since the symptoms of both moisture and dirt are similar, it will be neces- 
sary to melt the ice in the expansion valve. To melt the ice, apply a warm 
cloth to the body of the valve. (Do not apply torch to the expansion valve.) 
If the restriction is caused by moisture, the restriction will clear after an 
application of heat on the valve and will be indicated by the back pres- 
sure reading on the compound gage. 
d. Should the valve fail to become operative after heat has been 
applied, the indication would then point to a stuck-closed condition or 
62 restriction due to dirt or foreign substances. Should either of these two 
conditions prevail, the remedy is to remove the expansion valve, and 
clean or replace it. 
e. Adjusting the Expansion Valve. The expansion valve is automatic 
and under normal conditions no adjustments are required. A superheat 
adjustment is provided and the adjustment has been properly set at the 
factory and no attempt should be made to readjust unless it has been 
subjected to tampering or abuse. To adjust the superheat proceed as 
follows: 
(i) Remove the bottle racks and shelves from the evaporator. 
(2) Remove the valve stem (fig 37, item 5) exposing the adjusting 
stem (fig 37, item 2). 
(3) To raise the superheat turn the adjusting stem counter clock- 
wise. 
(4) To lower the superheat turn the adjusting stem clockwise. 
(5) Reinstall the valve stem cap gas tight. 
f. Removing the Expansion Valve. To remove the expansion valve 
proceed as follows: 
(1) Remove the bottle racks and shelves from the evaporator. 
(2) Install the gages. (See par 38.) 
(3) Pump down the system. (See par 41.) 
(4) Loosen the 2 screws on the thermostatic bulb clamp (fig 36, 
item 2) and remove bulb from clamp. 
(5) With a clean cloth wipe dry all fittings on the expansion valve. 
(6) Unscrew the suction and liquid line flare nuts (fig 36, items 3 
and 4) and remove from the valve. 
(7) The expansion valve is now free from the cabinet. 
g. Cleaning the Expansion Valve Strainer. To clean the expansion 
valve strainer proceed as follows: 
(1) Remove the expansion valve as outlined in par 50 f. 
(2) Unscrew the liquid line fitting (fig 37, item 6) from the valve. 
(3) Remove the strainer from the liquid line fitting (fig 37, item 7). 
(4) Clean the strainer using carbon tetrachloride. 
(5) Replace the strainer into the liquid line fitting and connect 
fitting to valve. 
(6) Install the expansion valve as outlined in par 50 h. 
h. Installing the Expansion Valve. Have the replacement valve avail- 
able for immediate installation and exercise care in not leaving the 
system open to the atmosphere longer than necessary. To install the 
expansion valve proceed as follows: 
63 (i) Reconnect the suction and liquid line flare nuts (fig 36, items 
3 and 4) to the expansion valve. Connections must be gas tight. 
(2) Secure the thermostatic bulb under the clamp at former loca- 
tion on the suction line between the center evaporator plates 
(fig 36) and tighten screws on clamp. 
(3) Purge the low side of the refrigeration system. (See par 43 b.) 
(4) Inspect to see that the suction service valve, discharge service 
valve and liquid receiver valve are back seated. 
(5) Test for leaks (See par 40.) 
Figure 37. Thermostatic expansion valve removed. 
Med. Dept. No. 
1. pR.2ji88 
2. 
3- 
4- 
5- 
6. 
7- 
Nomenclature 
Valve, expansion, thermostatic 
Super heat adjusting stem 
Thermostatic bulb clamp 
Thermostatic bulb clamp screws 
Valve stem cap 
Liquid line filtirig 
Strainer 
51. SERVICING THE CYLINDER HEAD SUCTION STRAINER 
a. Removing the Cylinder Head Suction Strainer. A strainer is 
installed in the suction port of the compressor head (fig 38, item 1) to 
prevent dirt or foreign substances from entering the compressor. To re- 
move the strainer proceed as follows: 
64 (i) Balance the pressure for compressor repairs. See par 42. 
(2) Disconnect the suction service valve from the compressor by 
removing the 2 screws, SR01142 (fig 39, item 4). Restrictor, 
9R27130 (item 2), will drop when suction service valve is 
removed. 
(3) Remove the strainer from the suction port of the compressor 
head. 
(4) Clean strainer with carbon tetrachloride or replace. 
b. Installing the Cylinder Head Suction Strainer. To install the 
strainer proceed as follows: 
(1) Insert the strainer in suction port of compressor (fig 38, item 1). 
(2) Assemble and attach with 2 screws, SR01142, the suction serv- 
ice valve, restrictor, 9R27130, and 2 new service valve gaskets, 
9R27142 (fig 39). 
CAUTION: RESTRICTOR MUST BE INSTALLED BE- 
TWEEN THE 2 GASKETS (fig 39). 
Figure 38. Cylinder head suction strainer. 
Med. Dept. No. 
7. 9li2yi26 
Nomenclature 
Strainer, suction head, cylinder 
65 (3) Purge the compressor. (See par 43 a.) 
(4) Back seat the suction and discharge service valves. 
(5) Remove gages and install gage plugs. 
(6) Install valve stem caps. 
(7) Pest for leaks. (See par 40.) 
Figure 39. Suction service valve restrictor. 
Med. Dept. No. 
7. ()R2~ I 
2. 9/^27750 
5. 9/^27742 
4. SR01142 
Nomenclature 
Gasket, service, valve 
Restrictor, valve, service, suction 
Gasket, service, valve 
Screw, 5/16-18 x 1 \/s inch hex. hd. cap 
52. SERVICING THE CYLINDER HEAD VALVE PLATE ASSEMBLY 
a. Testing the Cylinder Head Valve Plate Discharge Reeds. If 
the reeds on the cylinder head valve plate assembly leak very seriously, 
a reduction in the efficiency of the unit will result. The leakage will cause 
an increase in the running time as well as poor and inefficient refrigera- 
tion. To determine whether the reeds are leaking the following tests can 
be made: 
(1) Install the gages. (See par 38.) 
(2) Disconnect the extension cord plug from the source of supply, 
and permit the pressure in the low side (as noted on compound 
gage) to build up to at least 25 pounds pressure. 
(3) Test for leaks. (See par 40.) If any leaks are detected they must 
66 (4) Front seat the suction service valve, connect the extension cord 
plug to the source of supply, and operate compressor inter- 
mittently until the compound gage indicates o pounds pres- 
sure. (TO OBTAIN THIS READING IT WILL BE NECES- 
SARY TO MANUALLY CLOSE THE LOW PRESSURE 
CONTROL CONTACT POINTS BY REMOVING CON- 
TROL COVER PLATE AND MANUALLY DEPRESSING 
THE LEVER AS INDICATED IN FIG 19.) 
be corrected before proceeding with the test. 
(5) With the compressor idle (not operating), should the pressure 
indicated on the compound gage remain constant, the dis- 
charge reeds are seating properly. If the gage pressure rises 
more than 5 pounds in 1 minute, the discharge reeds are leak- 
ing and should be removed for replacement or repair. 
fa. Testing the Cylinder Head Valve Plate Suction Reeds. To 
determine whether the reeds are leaking the following tests can be made: 
(1) With the suction service valve still in a front seated position, 
operate the compressor until the oil pumping stops (oil pump- 
ing is indicated by sharp knocking in the compressor) and then 
allow compressor to operate continuously. TO DO THIS IT 
WILL BE NECESSARY TO BLOCK THE LOW PRES- 
SURE CONTROL CONTACT POINTS BY REMOVING 
THE CONTROL COVER PLATE AND WEDGING A 
PIECE OF WOOD BETWEEN THE INNER CASE OF 
THE CONTROL AND THE CONTACT ARM AS INDI- 
CATED IN FIG 18. 
(2) Compressor should be able to pump a vacuum of at least 20 
inches against normal head pressure. Failure to do this indi- 
cates that the gas is leaking back through the suction reeds. 
(3) To correct the leak, the reeds or the cylinder head valve plate 
assembly must be replaced. 
(4) Back seat the discharge and suction service valves, remove the 
gages, and reinstall the gage plugs and valve stem caps. 
(5) Remove the wooden wedge from the low pressure control and 
reinstall the control cover. 
c. Repairing fhe Cylinder Head Valve Plate Assembly. To repair 
the valve plate assembly proceed as follows; 
(1) Balance the pressure for compressor repairs. (See par 42.) 
(2) Remove the 10 compressor head screws, SR01139 (fig 53, item 
0- 
(3) Remove the cylinder head valve plate assembly between the 
compressor head and cylinder block. 
67 (4) Determine the extent of replacement parts required and re- 
place what is necessary on the cylinder head valve plate pro- 
viding the valve plate scats have not been scratched or injured, 
and are in condition to justify repairs. 
(5) Reinstall cylinder head valve plate assembly using 2 new 
gaskets, gR27132 and gR2yi34. 
(6) Reinstall the 10 compressor head screws setting up gas tight by 
pulling down evenly, working from side to side. 
(7) Purge the compressor. (See par 43 a.) 
(8) Back seat the suction and discharge service valves, remove the 
gages, and reinstall the gage plugs and valve stem caps. 
(9) Test for leaks. (See par 40.) 
d. Replacing the Cylinder Head Valve Plate Assembly. If inspec- 
tion of the valve plate seats indicate that they are scratched or injured in 
any way, replacing the reeds must not be attempted, but instead the entire 
valve plate assembly must be replaced. To replace the valve plate assem- 
bly proceed as follows: 
(1) Balance the pressure for compressor repairs. (See par 42.) 
(2) Remove the 10 compressor head screws, SR01139 (fig 53, item 
0- 
(3) Remove the valve plate assembly between the compressor head 
and cylinder block. 
(4) Reinstall valve plate assembly using 2 new gaskets, 9R27132 
and 9R27134. 
(5) Reinstall the 10 compressor head screws setting up gas tight by 
pulling down evenly, working from side to side. 
(6) Purge the compressor. (See par 43 a.) 
(7) Back seat the suction and discharge service valves, remove the 
gages, and reinstall the gage plugs and valve stem caps. 
(8) Test for leaks. (See par 40.) 
53. SERVICING THE COMPRESSOR SERVICE VALVES 
not be encountered in the operation of the compressor service valves. 
The valve seats are enclosed and their operation is manual (fig 13). The 
valve stem packing nuts must be kept tight at all limes to prevent re- 
frigerant leaks. To remove the suction service valve proceed as follows: 
Removing the Suction Service Valve. Service difficulties should 
(1) Pump down the system. (See par 41.) 
(2) Disconnect the extension cord plug from the source of supply. 
(3) Disconnect the suction service valve from the compressor head 
by removing the 2 screws, SR01142 (fig 39, item 4). Restrictor, 
9R27130 (item 2), will drop when valve is removed. 
68 (4) Remove the 14 inch flare nut from the elbow fitting (fig 40, 
item 1). on suction line where tubing is connected to the low 
pressure control. 
(5) Swing suction line and suction service valve toward the rear of 
the cabinet in a long, easy sweep to prevent kinking the line. 
(6) Hold valve with pliers and apply torch to the sweat fitting to 
remove the valve (fig 41). 
b. Installing the Suction Service Valve. To install the suction serv- 
ice valve proceed as follows 
(1) Sweat new valve on suction line and permit to cool 
(2) Swing suction line and valve into proper position. 
(3) Connect the valve to the compressor head with 2 screws, 
SR01142, using 2 new gaskets, gR27i42. Make certain that the 
restrictor, 9R27130 (fig 39, item 2), is assembled between the 
2 gaskets. 
(4) Reconnect the 14 inch flare nut to the elbow fitting on the 
Figure 40. Low pressure control connections. 
Med. Dept. No. 
1. pR 27220 
2. pR 2y 226 
3■ 9^7236 
4. pR2jo62 
Nomenclature 
Nut, flare, 14 inch 
Ell, control, pressure, low 
Tee, line, suction 
Valve, service, suction 
69 suction line where the tubing is connected to the low pressure 
control. 
(5) Purge the low side of the refrigeration system. (See par 43 b.) 
(6) Test for leaks. (See par 40.) 
c. Removing the Discharge Service Valve. To remove the discharge 
service valve proceed as follows: 
(1) Remove the refrigerant from the system. (See par 44 b.) 
(2) Disconnect the discharge service valve from the compressor 
head by removing the 2 screws, SR01142. 
(3) Hold valve with pliers and apply torch to the sweat fitting 
until the solder is melted (fig 42). Pull the valve free from the 
line. 
Figure 41. Unsoldering suction service valve 
Med. Dept. No. 
1. 9R2-062 
2. 
3- 
4. gR2j2io 
5- 
6. SR01140 
Nomenclature 
Valve, service, suction 
Condenser soldered connection 
Dehydrator soldered connection 
Valve, receiver, liquid 
Condenser outlet soldered connection 
Screzu, 14-20 x i/2 inch hex. hd. cap 
d. Installing the Discharge Service Valve. To install the discharge 
service valve proceed as follows 
(1) Sweat the new valve on the discharge line and permit to cool. 
(2) Connect the valve to the compressor head with the 2 screws, 
SR01142. using a new gasket, 9R27142. 
70 Figure 42. Unsoldering discharge service valve. 
(3) Purge the entire refrigeration system. (See par 43 c.) 
(4) Add Freon 12 refrigerant to the system. (See par 44 a.) 
(5) Test for leaks. (See par 40.) 
(6) Back seat the suction and discharge service valves, remove 
gages and install plugs. 
(7) Reinstall the 3 valve stem caps. 
54. SERVICING THE LIQUID RECEIVER 
a. Removing the Liquid Receiver. To service the liquid receiver or 
its component parts, the refrigerant must be pumped back into the re- 
ceiver and then removed from the system. To remove the receiver proceed 
as follows: 
(1) Remove the refrigerant from the system. (See par 44 b.) 
(2) Remove the liquid line from the dehydrator by unscrewing the 
1/ inch flare nut. 
(3) Unscrew the dehydrator from the liquid receiver valve (fig 24, 
item 1). 
(4) Remove condenser inlet tube at top of receiver by applying 
torch and unsweating the soldered connection (fig 41, item 3). 
(5) From the under side of the unit base, remove the nut from the 
stud extending from the base of the receiver through the base 
of the condensing unit. 
(6) Lift the receiver clear from the unit compartment. 
b. Installing the Liquid Receiver. To install the receiver proceed as 
follows: 
(1) Place receiver in position on the condensing unit base and 
secure with nut to the stud extending from the base of the 
receiver through the base of the condensing unit. 
(2) Connect the condenser inlet tube to the top of the receiver by 
applying torch and sweating the soldered connection (fig 41, 
item 3). 
71 (3) Screw the dehydrator on to the liquid receiver valve. 
(4) Connect the liquid line by screwing the 1/4 inch flare nut to 
the top of the dehydrator. 
(5) Purge the entire refrigeration system. (See par 43 c.) 
(6) Add refrigerant to the system. (See par 44 a.) 
(7) Test for leaks. (See par 40.) 
not be encountered in the operation of the liquid receiver valve. The 
valve and seat are enclosed and the operation is manual. The valve stem 
packing nut must be kept tight at all times to prevent refrigerant leaks 
(fig 14). To remove the liquid receiver valve proceed as follows: 
c. Removing the Liquid Receiver Valve. Service difficulties should 
(1) Remove the liquid receiver as outlined in par 54 a. 
(2) With a wrench unscrew the liquid receiver valve from the 
receiver (fig 41, item 4). 
d. Installing the Liquid Receiver Valve. To install the liquid re- 
ceiver valve proceed as follows: 
(1) Before installing a new valve in the receiver, apply a thin coat- 
ing of lead, white, basic-carbonate, type C, on the threads of 
the valve. 
(2) Screw valve into the receiver and tighten with a wrench. 
CAUTION: WHEN TIGHTENING THE VALVE CARE 
MUST BE EXERCISED TO PREVENT DAMAGE TO 
THE 14 INCH FLARE CONNECTING THREADS. 
(3) The 14 inch flare connector must be turned to an upright posi- 
tion to permit attachment of the dehydrator. 
(4) Install the receiver. (See par 54 b.) 
e. Removing the Receiver Fuseable Plug. The fuseable plug is a 
pipe plug consisting of a core filled with a low-melting point alloy (fig 9, 
item 6). In the event of an excessive temperature, the alloy in the core 
melts allowing the refrigerant to be released to the atmosphere thereby 
preventing excessive pressures from rupturing the condenser, liquid re- 
ceiver and other component parts of the unit. To remove the fuseable 
plug from the liquid receiver proceed as follows: 
(1) In the event there is still some refrigerant remaining in the 
system it must be removed as outlined in par 44 b. 
(2) Unscrew the fuseable ping with a 10 inch adjustable wrench. 
Exercise care to prevent pipe thread compound or dirt from 
falling into the receiver. 
f. Installing the Receiver Fuseable Plug. To install the fuseable 
plug proceed as follows: 
72 (i) Apply a thin coat of lead, white, basic-carbonate, type C, on 
the threads of the new pipe. 
(2) Screw the plug into the receiver setting up gas tight. 
(3) Purge the entire refrigeration system. (See par 43 c.) 
(4) Add refrigerant to the system. (See par 44 a.) 
(5) Test for leaks. (See par 40.) 
55. SERVICING THE CONDENSER 
a. Removing the Condenser. If proper diagnosis indicates that the 
condenser is in need of repair caused by leaks or a restriction in the con- 
denser coils, the condenser must be removed as follows: 
(1) Remove the refrigerant from the system. (See par 44 b.) 
(2) Apply torch and unsweat soldered connection at the outlet 
point of the receiver (fig 41, item 5). 
(3) Remove discharge service valve from the compressor head. 
(4) Apply torch and unsweat soldered connection on the discharge 
service valve and remove valve (fig 42). 
(5) Remove the 4 supporting screws holding the condenser to the 
unit base (fig 41, item 6). 
(6) Lift the condenser clear from the unit compartment. 
b. Installing the Condenser. To install the condenser proceed as 
follows: 
(1) Place the condenser in position on the condensing unit base 
and secure with the 4 supporting screws and nuts (fig 41, item 
6). 
(2) Connect the discharge service valve to the inlet end of the 
condenser line and resweat the soldered connection (fig 42). 
(3) Connect the discharge service valve to the head of the com- 
pressor. (Use new gasket, 9R27142.) 
(4) Connect outlet line of the condenser to the inlet point of the 
receiver by resweating the soldered connection (fig 41, item 5). 
(5) Purge the entire refrigeration system. (See par 43 c.) 
(6) Add refrigerant to the system. (See par 44 a.) 
(7) Test for leaks. (See par 40.) 
56. SERVICING THE COMPRESSOR BELT 
a. Adjusting the Belt Tension. The belt should last an indefinite 
length of time if it has been operated under proper tension and the pulley 
is in proper alinement. Oil or lubricants of any kind should not be applied 
to the belt, and in the event that a slight stretching has occurred, the belt 
can easily be adjusted and the slack taken up. To adjust the belt tension 
proceed as follows: 
73 Figure 43. Inspecting belt tension. 
(i) The tension of the belt should permit a depression of about 
1/2 inch midway between pulleys as indicated in fig 43. 
(2) Loosen the 4 nuts at the base of the motor and slide the motor 
away from the compressor to increase the tension, and toward 
(3) Square the motor with the condensing unit base to secure 
the compressor to decrease the tension. 
proper alinement. 
(4) Tighten the 4 nuts at the base of the motor. 
b. Removing the Belt. To remove the belt proceed as follows: 
(1) Disconnect the extension cord plug from the source of supply. 
(2) Working from the front of the cabinet, grasp the compressor 
flywheel with the left hand at the upper portion of the outer 
edge. 
(3) With the right hand guide the belt toward the rear of the 
cabinet (away from the compressor). 
(4) With the left hand rotate the flywheel counter clockwise. 
(5) As the belt frees from the flywheel, slip it over the motor pulley 
and fan, and remove the belt from the unit compartment. 
c. Installing the Belt. To install the belt proceed as follows: 
(i) Place one loop of the belt over the fan and fit into the motor 
pulley. 
74 (2) Start the belt in the groove on top of the flywheel. 
(3) With the right hand guide the belt at the top of the flywheel, 
and with the left hand guide the belt into position rotating 
flywheel counter clockwise. 
(4) Adjust the belt for proper tension. (See par 56 a.) 
57. SERVICING THE COMPRESSOR ASSEMBLY 
a. Removing the Compressor. Except for replacing the cylinder 
head valve plate assembly, head gaskets, compressor service valves, oil 
and refrigerant, the compressor must be removed from the unit for any 
other servicing. To remove the compressor assembly proceed as follows: 
(1) Pump down the system. (See par 41.) 
(2) Disconnect the discharge and suction service valves from the 
compressor by removing 4 screws, SR01142. RESTRICTOR, 
9R27130, WILL DROP WHEN SUCTION SERVICE 
VALVE IS REMOVED (FIG 39). 
(3) Remove belt. (See par 56.) 
(4) Remove the 4 screws, SR01013, from the base of the com 
pressor. 
(5) Remove the compressor with flywheel attached through front 
of cabinet (fig 44). 
Figure 44. Removing compressor. 
75 b. Installing the Compressor. To install the compressor proceed as 
follows: 
(i) With flywheel attached, place compressor on condensing unit 
base. 
(2) Secure compressor with 4 screws, SR01013, to the unit base. 
(3) Connect the discharge and suction service valves with 4 screws, 
SR01142, to the compressor head using new gaskets, 9R27142. 
IN CONNECTING THE SUCTION SERVICE VALVE, 
MAKE CERTAIN THAT THE RESTRICTOR. 9R27130 
(FIG 39, ITEM 2), IS ASSEMBLED BETWEEN THE 2 
GASKETS. 
(4) Purge the compressor body. (See par 43 a.) 
(5) Install the pressure gage plug. 
(6) Back seat the suction and discharge service valves. 
(7) Remove the compound gage and install gage plug. 
(8) Back seat the suction and discharge service valves and the 
liquid receiver valve. 
(9) Install the 3 valve stem caps 
(10) Test for leaks. (See par 40.) 
assembly, the compressor flywheel must be removed. To remove the fly- 
wheel proceed as follows: 
c. Removing the Compressor Flywheel. To service the shaft seat 
(1) Remove the compressor. (See par 57 a.) 
(2) Install the flywheel puller, TR00041, on the flywheel over shaft 
nut (fig 45, item 4). 
(3) Tighten wheel puller bolts alternately with a wrench, TRo 1931 
(fig 45, item 5), until flywheel snaps against the nut. 
(4) Remove the flywheel puller, shaft nut, lockwasher and fly 
wheel. 
d. Installing the Compressor Flywheel. To install the flywheel pro 
ceed as follows: 
(1) Reinstall flywheel on shaft. 
(2) Secure flywheel to shaft with nut and lockwasher. 
(3) Tighten nut. Due to taper of the shaft the flywheel is self 
alining. 
76 Figure 45. Removing the compressor flywheel. 
Med. Dept. No, 
/. 9R27092 
2. SROIIJ 2 
5. SR00653 
4. TROOO^I 
5. TR0193I 
Nomenclature 
Flywheel, compressor, cylinder 
Washer, lock, screxv size 9/16 
Nut, 9/16-18 hex. 
Puller, wheel, fly 
Wrench, 9/16 box 
Removing the Eccentric Shaft Seal Assembly. Should the seal 
face become scored or pitted by dirt or foreign substances, the seal will 
eventually leak releasing the refrigerant and oil. Should this happen, the 
seal assembly must be replaced. To remove the shaft seal assembly proceed 
as follows; 
(1) Remove the compressor. (See par 57 a.) 
(2) Remove the fly wheel. (See par 57 c.) 
(3) Lay compressor back (fig 46) to prevent the oil from leaking 
out of the crankcase. 
(4) Remove the eccentric shaft seal cap and gasket by removing 
the 6 screws (fig 46). 
77 (5) Remove the shall seal assembly consisting ol the eccentric shall 
seal gasket, shall seal ring, shall seal shoulder and shall shoul- 
der gasket (fig 47). 
Figure 46. Removing the eccentric shaft seal assembly. 
Med. Dept. No. 
1. Snoopy 
2. 9R2/I36 
4. gR2ji2j 
Nomenclature 
Screw, 5/16-18 x inch hex. hd. cop 
Gasket, cap, seal, shaft, eccentric 
Cap, seal, shaft, eccentric 
seal assembly proceed as follows: 
f. Installing the Eccentric Shaft Seal Assembly. To install the shaft 
(1) Assemble the shaft seal gasket, 9R27114, in the recess of the 
shall seal ring, gR27ii2, and slide assembly (gasket end first) 
over shaft (fig 47). 
(2) Coat the 2 faces of the sealing surfaces with refrigerant oil 
(OR). 
(3) Assemble shaft seal shoulder, gR27ii6, and shaft shoulder 
78 gasket, 9R27118, into the shaft seal cap, and slide 
into position over the shaft. Use a new shaft seal cap gasket, 
9R27J36 (fig 47). 
(4) Secure the assembly to the compressor by tightening the 6 cap 
screws, SR00935, drawing them up uniformly from side to side. 
(5) Reinstall flywheel. (See par 57 d.) 
(6) Install compressor. (See par 57 b.) 
Figure 47. Eccentric shaft seal assembly removed 
Med. Dept. No. 
1. gRzyiij 
2. )R2JI 12 
5. gR2yn6 
7. gR2'jii8 
5. (jR2JI^6 
6. SRoogjj 
7. 9^27/27 
Nomenclature 
Gasket, seal, shaft, eccentric 
Ring, seal, shaft, eccentric 
Shoulder, seal, shaft, eccentric 
Gasket, shoulder, shaft, eccentric 
Gasket, cap, seal, shaft, eccentric 
Screw, 5/16-18 x inch hex. hd. cap 
Cap, seal, shaft, eccentric 
g. Disassembly of Compressor. With the compressor body removed 
from the unit and the flywheel removed from the shaft as previously out- 
lined, the compressor can be completely dismantled as follows: 
(1) Remove the oil level plug (fig 48, item 1). 
(2) Place the compressor on its side and allow the oil to drain from 
the crankcase into a r eceptacle. 
(3) Remove the oil pan (fig 48, item 2) by the removal of 12 cap 
screws located under the pan. Lightly tap the oil pan to break 
the gasket adhesion. 
(4) Remove the eccentric shaft seal assembly. (See par 57 c.) 
79 Figure 48. Removing oil from compressor. 
Med. Dept. No. 
1. 9R27068 
2. pR.2yi20 
Nomenclature 
Plug, level, oil 
Pan, oil, cylinder, compressor 
(5) Remove the shaft thrust cap (fig 49, item 2) at thrust end of 
shaft by the removal of 3 cap screws (fig 49, item 1). CAU- 
TION: WHEN THE SHAFT THRUST CAP IS RE- 
MOVED, THE SHAFT THRUST BALL (FIG 49, ITEM 
4) AND THE SHAFT THRUST DISC (FIG 49, ITEM 5) 
WILL DROP OUT DUE TO THE TENSION OF THE 
SHAFT THRUST SPRING (FIG 49, ITEM 6). 
(6) Remove the shaft thrust spring from the hollow of the shaft. 
(7) Remove the Allen set screw located in the center of the com- 
pressor eccentric (fig 50, item 1). 
(8) To remove the Allen set screw, it may be necessary to aline the 
eccentric. This can be done by replacing the flywheel nut on 
the shaft and rotating the shaft by means of a wrench (fig 50, 
item 6). 
(9) Retain alinement of eccentric with the pistons by spanning 
80 Figure 49. Eccentric shaft thrust cap removed 
Med. Dept. No. 
/. SRoopjj 
2. pR.2JI22 
3• 9R27138 
4. 9R2JIQ4 
5. pR2yio6 
6. pR2yio2 
Nomenclature 
Screxv, 5/16-18 x z/4 inch hex. hd. cap 
Cap, thrust, shaft, eccentric 
Gasket, cap, thrust, shaft, eccentric 
Ball, thrust, shaft, eccentric 
Disc, thrust, shaft, eccentric 
Spring, thrust, shaft, eccentric 
the shaft with a 10 inch adjustable wrench, TRoi882, at a 
point between the eccentric and the seal end main bearing as 
illustrated in fig 51. The procedure will prevent breaking the 
connecting rod as the shaft is forced out of the compressor 
(10) Drive the shaft from the thrust end by using a driving bar to 
prevent damage to the thrust end of the shaft (fig 51). 
(11) Remove the pistons, connecting rods and eccentric as an assem- 
bly as indicated in fig 52. 
(12) If the original parts are to be used, mark the skirt of the piston, 
wrist pin end plug, connecting rod and eccentric with the edge 
of a file. This is for the purpose of identification and must be 
followed during reassembly in order to reinstall the same parts 
to their original location. MARK 1 SET ONLY AS ILLUS- 
TRATED IN FIG 52. 
81 Med. Dept. No. 
1. SR01052 
2. 
3 
4- 
5- 
6. SR00653 
Figure 50. Removing the Allen set screw from compressor eccentric. 
Nomenclature 
Screw, 5/16-18 x y8 inch Allen head 
Thrust end of compressor 
Eccentric boss 
Oil level gage plug hole 
Connecting rod oil holes 
Nut, g/16-18 hex, 
Med. Dept. No. 
I. TR01SS2 
Figure 51. Removing compressor shaft. 
Nomenclature 
Wrench, 10” adjustable 
82 Figure 52. Marking of compressor parts for reassembly. 
Nomenclature 
i. Wrist pin end plug 
Connecting rod 
2. Skirt of piston 
Figure 53. Removing compressor head. 
Med. Dept. No. 
/. SRoujp 
2. TRoipji 
Nomenclature 
Screw, 5/16-18 x 17/8 inch hex. hd. cap 
Wrench, 9/16 box 
83 Figure 54. Removing the cylinder head valve plate assembly. 
Med. Uept. No. 
/. c)R2yoy4 
Nomenclature 
Plate, valve, head, cylinder 
(13) Remove the 10 cap screws from the compressor head (fig 53) 
and remove the head and valve plate assembly by striking these 
parts lightly using a wooden block to break the gasket adhe- 
sion (fig 54). 
(14) In the event of a broken connecting rod and the piston dam- 
aged, the piston can be forced out by driving it down through 
the crankcase. 
(15) To remove the piston from a broken connecting rod, pry out 
the wrist pin end plugs (fig 55) and drive the wrist pin from 
the piston and connecting rod using a brass rod to avoid injury 
to the wrist pins and wrist pin bores. 
(16) Disassemble cylinder head valve plate assembly (fig 56) by 
depressing the valve plate discharge reed locks (fig 57, item 5) 
and removing the reed discharge screws (fig 57, item 6). This 
releases the discharge reed springs (fig 57, item 4), discharge 
reed cushions (fig 57, item 3), and discharge reeds (fig 57, item 
2). Hie suction reeds (fig 58, item 2) can be disassembled by 
removing the suction reed screws (fig 58, item 3). 
84 Figure 55. Removing wrist pin end plug. 
i. Wrist pin end plug 
Figure 56. Disassembling cylinder head valve plate assembly. 
Med. Dept. No. 
1. 9R27074 
2. 9R27134 
3. 91127132 
Nomenclature 
Plate, valve, head, cylinder 
Gasket, plate, head, cylinder 
Gasket, head, cylinder 
85 Figure 57. Discharge valve reed disassembled. 
1. 
2. gR2yoSo 
3. pR 23084 
4. PR2708 2 
5. pR2jo88 
6. pR2jo86 
Med. Dept. No. 
Discharge valve seat 
Reed, discharge, plate, valve 
Cushions, discharge, reed, plate, valve 
Spring, reed, discharge, plate, valve 
Locks, discharge, reed, plate, valve 
Screw, discharge, reed, plate, valve 
Nomenclature 
h. Reassembling the Compressor. Each part should be thoroughly 
inspected and any part showing excessive wear should be replaced. A 
complete new set of compressor gaskets must be used and all surfaces free 
of old gasket material. Every precaution must be taken to prevent dirt or 
moisture from getting on the parts during the reassembling. To re- 
assemble the compressor proceed as follows: 
(1) Before reassembling, clean all parts thoroughly by immersing 
them in carbon tetrachloride Or a dry cleaning solvent, using a 
stiff brush to completely wash the dirt and dust from all 
grooves, crevices and holes. 
(2) If the original parts are to be used, the markings must be fol- 
lowed making sure that the same pistons and wrist pins are 
installed on the same connecting rods and are assembled back 
in the same cylinders. 
86 Med. Dept. No. 
/. 
2. 9R2JO/6 
3. (jR2yoy8 
Figure 58. Suction valve reed disassembled 
Nomenclature 
Suction valve seat 
Heed, suction, valve, plate 
Screws, reed, suction, plate, valve 
(3) Assemble pistons to connecting rods by placing refrigerant oil 
on the wrist pins and insert the wrist pins through the pistons 
and connecting rods. Make sure there is an even clearance on 
each end of the wrist pins. If it is necessary to drive the wrist 
pins use a brass rod to avoid injury to wrist pins and wrist pin 
bores. Assemble wrist pin end plugs (fig 55) into the wrist pins 
by depressing plugs into place. 
(4) Assemble the connecting rods on the eccentric as illustrated in 
fig 52. Place refrigerant oil on the eccentric bearing surfaces 
(fig 50). Be sure the oil holes (item 5) on the connecting rods 
face toward the oil level gage plug hole (item 4) and the boss 
(item 3) of the eccentric faces towards the thrust end (item 2) 
of the compressor. 
(5) Stand the compressor with the crankcase up and oil the pistons 
with refrigerant oil. Insert the pistons, connecting rods and 
eccentric assembly through the crankcase and fit pistons into 
cylinders alining shaft opening in eccentric with main bear- 
ings of the compressor (fig 50). 
87 Figure 59. Compressor disassembled. 
88 Med. Dept. No. 
Nomenclature 
Med. Dept. No. 
Nomenclature 
r. 
pR.2yi2o 
Pan, oil, cylinder, compressor 
20. 
gR 2y 2 32 
Gasket, plug, level, oil 
2. 
SR01052 
Screw, 5/16-18 x %/% inch Allen head 
21. 
gR2yo68 
Plug, level, oil 
3- 
()R2yijfo 
Gasket, pan, oil 
22. 
SRoog35 
Screw, 5/16-18 x y4 inch hex. hd. cap 
4- 
SRoogyy 
Screw, 5/16-18 x z/4 inch hex. hd. cap 
23. 
SR01132 
Washer, lock, screw size g/16 
5- 
gRzy 122 
Cap, thrust, shaft, eccentric 
24. 
SR00653 
Nut, g/16-18 hex. 
6. 
9R27138 
Gasket, cap, thrust, shaft, eccentric 
25. 
gR2yi2j 
Cap, seal, shaft, eccentric 
7- 
(JR2JIOJ 
Ball, thrust, shaft, eccentric 
26. 
gR2y 136 
Crasket, cap, seal, shaft, eccentric 
8. 
gR2yio6 
Disc, thrust, shaft, eccentric 
2y. 
gR2yn8 
Gasket, shoulder, shaft, eccentric 
9- 
9R2JIG2 
Spring, thrust, shaft, eccentric 
28. 
gR2yi 16 
Shoulder, seal, shaft, eccentric 
IO. 
9R2J132 
Gasket, head, cylinder 
2g. 
gR2yii2 
Ring, seal, shaft, eccentric 
ii. 
gR2yoy^ 
Plate, valve, head, cylinder 
30. 
gR2yn4 
Gasket, seal, shaft, eccentric 
12. 
9R2JI34 
Crasket, plate, head, cylinder 
31- 
gR2y 100 
Key, eccentric, shaft, compressor 
n- 
gR2yogo 
Head, cylinder, compressor 
32. 
Com pressor piston 
J4- 
SRonyg 
Screw, 5/16-18 x i7/8 inch hex. hd. cap 
33- 
gR2yogj 
Piston and connecting rod, compressor 
T5‘ 
gR2y 126 
Strainer, suction, head, cylinder 
34- 
gR2yog6 
Eccentric, compresssor 
16. 
gR2ji30 
Restrictor, valve, service, suction 
35- 
SR00156 
Washer, lock, screw 5/16 
I7- 
gR2yij2 
Gasket, service, valve 
36. 
SR01013 
Screw, 5/16-18 x 5/g inch hex. hd. cap 
18. 
gR2jog8 
Shaft, eccentric, compressor 
37• 
gR2yog2 
Flywheel, compressor, cylinder 
19. 
gR2yi28 
Block, cylinder, compressor 
89 Figure 60. Installing piston assembly into compressor, 
(6) With compressor shaft key, 9R27100 (fig 59, item 31), in slot 
of shaft, insert shaft through seal housing end of compressor 
alining key with keyway of eccentric. Place flywheel nut on 
shaft and drive the shaft into position using a wooden mallet 
or similar soft composition to avoid injury to the threads and 
shaft. Secure eccentric to shaft by tightening the Allen set 
screw (fig 50, item 1) in the eccentric. 
(7) Insert the shaft thrust spring in the thrust end of the shaft and 
assemble the shaft thrust disc and shaft thrust ball into posi- 
tion (fig 49). With the shaft thrust disc and shaft thrust ball in 
position, reinstall the shaft thrust cap with the 3 cap screws. 
(Use new gasket, 9R27138.) Tighten the cap screws evenly. 
(8) Reinstall the eccentric shaft seal assembly. (See par 57 f.) 
(9) Reinstall the oil pan (using new gasket, 9R27140) with 12 cap 
screws and lockwashers, tightening evenly from side to side. 
90 Figure 61. Cross section of compressor assembly. 
91 (10) Reassemble cylinder head valve plate assembly making sure 
that the seats are absolutely clean. It cleaning is necessary, use 
a chamois it available. If new parts are not needed, care should 
be taken making sure the old parts are installed in their orig- 
inal position. In assembling the discharge valve reeds, aline 
components as illustrated in fig 57. Either side of reed may be 
used as a seating surface. Assemble the suction valve reeds on 
the opposite side of the valve plate with the curvatures up to 
create tension on the seating surfaces. Secure the reeds to the 
plate with the 4 suction reed screws (fig 58). 
(11) Place a few drops of refrigerant oil on the heads of the pistons 
and install the cylinder head valve plate assembly on the com- 
pressor using 2 new gaskets, 9R27132 and 9R27134. The valve 
plate assembly and gaskets will only fit in their correct position 
when holes are properly alined. 
(12) Reinstall the compressor head with the 10 cap screws drawing 
the screws up gas tight working evenly from side to side. 
NOTE: The compressor head can only be installed in its correct posi- 
tion due to its contour and fit in the valve plate assembly. 
(13) Inspect the cylinder head suction strainer making sure that it 
is not restricted. Insert the strainer into the suction port of the 
compressor (fig 38). 
(14) Remove the oil level plug, and with the aid of a funnel fill the 
crankcase with 1.% pints of pure dehydrated refrigerant oil 
(OR) (fig 23). Reinstall the oil level plug making sure that the 
plug gasket is in place under the hex head of the plug. 
(15) Reinstall the flywheel on the compressor shaft. (See par 57 d.) 
58. SERVICING THE ELECTRIC MOTOR 
a. Motor Rotation Adjustment. The electric motor is of the revers- 
ible type, but should only be operated in one direction on this refrigera- 
tor. That direction is counter clockwise when facing the commutator end 
of the motor. Any adjustment of the brush setting should not be required; 
however, should the setting be accidently moved, it must be reset to 
insure the proper starting torque and rotation of the motor. To adjust 
the rotation proceed as follows: 
(1) To change the adjustment indicated by markings on fig 62, 
loosen the screw (item 1) and aline mark evenly with the mark 
indicated on the end plate. This is a very critical adjustment 
and care must be exercised in bringing the 2 marks to perfect 
alinement. The marking on the right (item 3) is the one to 
aline with the end plate marking (item 4) to insure proper 
rotation of the motor. After making the adjustment, tighten 
the screw (item 1) thereby locking the adjustment in place. 
92 Figure 62. Adjusting motor rotation. 
Figure 63. Cleaning the motor commutator. 
i. Inspection cover plate 
93 b. Cleaning the Motor Commutator. The motor commutator will 
require cleaning due to accumulation of oil and dust. Excessive arcing 
and sluggish starting are the results of this condition. To clean the com- 
mutator proceed as follows: 
(i) Remove the inspection cover plate (item i) on the end plate 
of the motor (fig 63). 
(2) With the motor in operation gently hold a piece of fine grade 
sandpaper against segments of the commutator long enough to 
remove the dirt accumulation. (DO NOT’ USE EMERY 
PAPER.) 
(3) Replace the inspection cover plate and secure with 2 screws. 
c. Removing the Electric Motor Carbon Brushes. Worn motor 
brushes are indicated by sluggish starting, excessive arcing or failure to 
start the motor. To remove the motor brushes proceed as follows: 
(1) Disconnect the extension cord plug from the source of supply. 
(2) Remove the 4 nuts from the end plate bolts. 
(3) Remove the end plate by tapping around the flange until plate 
is free and can be removed from the shaft. 
(4) Lift brush holder spring and move to one side freeing brushes 
for removal. (BRUSHES MUST ALWAYS BE REPLACED 
IN SETS OF 4 - 2 PAIRS.) 
new brushes proceed as follows: 
d. Installing the Electric Motor Carbon Brushes. To install the 
(1) Insert the new brushes in the brush holder and bend the brush 
holder springs in position so they rest on top of the brushes. 
(2) Replace end plate on shaft by guiding the index plate through 
the slot in the brush holder. 
(3) Tap flange to secure the end plate to the motor frame and 
install nuts on the end plate bolts. Tighten the bolts uniformly 
by alternating from side to side. In tightening the bolts inspect 
the armature for free movement at intervals to assure proper 
alinement. Should the end plate fail to aline properly by 
tightening the bolts, tap lightly around the flange of the end 
plate until it fits snugly against the motor frame. 
(4) Reconnect the extension cord plug to the source of supply. 
e. Testing the Field Coils for Short Circuit. To test the field coils 
proceed as follows: 
(1) Remove the armature. (See par 58 h.) 
(2) Make a separate watt meter reading on the field coil windings. 
In some cases the short circuited coil may be located by feeling 
94 the coils and noting it one feels much hotter than the other. 
(3) The presence of an increase in the magnetic noise over and 
above the normal noise may also indicate a short circuited held 
(4) Should an inspection indicate that the coils are short circuited 
the motor must be replaced. 
f. Testing the Armature for Short Circuit. To test the armature 
proceed as follows; 
(1) Remove the brushes. (See par 58 c.) 
(2) Reinstall the end plate on the motor. 
(3) Remove the belt. (See par 56 b.) 
(4) Reconnect the extension cord plug to the source of supply. 
(5) Turn the fan to rotate the armature within the held coils and 
motor housing. If the armature rotates uniformly throughout 
the complete revolution, the armature coils are not short cir- 
cuited. Should the armature tend to stop or drop forward or 
backward of its own accord, then the armature winding is 
shorted and the armature must be replaced. 
g. Testing the Field Coils or Armature for Open Circuit. If an 
inspection indicates the following symptoms the motor must be replaced 
(See par 58 1.) 
(1) Excessive sparking when the motor starts. 
(2) Refusal to start at certain positions of the armature. 
(3) A humming sound when the circuit to the motor is closed. 
h. Removing the Armature. To remove the armature proceed as 
follows: 
(1) Remove the motor. (See par 581.) 
(2) Remove the pulley end plate by removing the 4 end plate bolts 
and nuts. 
(3) Remove the end plate by tapping around the flange until the 
plate is free and can be removed from the shaft. 
(4) Grasp the shaft and pull the armature forward until it is clear 
of the field coils and motor frame (fig 64). 
i. Installing the Armature. To install the armature proceed as fol- 
lows: 
(1) Slide the armature into the motor frame by placing the pulley 
end of the shaft into the pulley end [date. Should difficulty be 
experienced in sliding the shaft through the motor end plate 
bearing, remove the armature and with your finger work the 
95 Figure 64. Removing the armature. 
oil wicking back into the oil well. This will prevent obstruc- 
tion and allow the motor shall to pass into the end plate 
bearing. 
(2) Replace end plate and secure with end plate bolts and nuts. 
Should the end plate fail to aline by tightening the bolts, tap 
lightly around the flange until it fits snugly against the motor 
frame. 
(3) Replace the motor on the condensing unit as outlined in par 
58 1. 
/. Removing the Overload Protector. The motor is equipped with 
a built-in overload protector. The principle upon which this protective 
device functions is a thermostatic circuit breaker. When the temperature 
of the motor rises above normal operating conditions, the circuit is 
broken, stopping the motor and permitting it to cool to a normal tem- 
perature. When the normal temperature again prevails the protector 
control closes the circuit and the motor resumes operation. This cycle of 
intermittent operation may continue a number of times until the condi- 
96 tion that is causing the overload is corrected or the equipment is down to 
normal and continuous operation is resumed. The protector is set at the 
factory and no adjustments should be made in the field. IE intermittent 
operation continues with all conditions normal, and it is determined that 
the difficulty lies within this protective device, it must be replaced. To 
remove the overload protector proceed as follows: 
(i) Remove the motor as outlined in par 58 1. 
(2) Remove pulley end plate Jay removing the end plate nuts and 
bolts, and tapping around the llange until the plate is free and 
can be removed from the shaft (fig 65, item 4). 
(3) Remove screw (fig 65, item 2) retaining overload protector in 
recess of the end plate. 
(4) Remove tape and fibre cover (fig 65, item 1) exposing 4 soldered 
terminals. (NOTATION MUST BE MADE OF COLOR 
CODE OF CABLES AND THEIR RESPECTIVE AT- 
TACHED POSITIONS.) Unsolder terminals and remove 
wiring. 
k. Installing the Overload Protector. To install the overload pro- 
tector proceed as follows: 
(1) Resolder leads to the terminals in accordance with color code. 
(2) Retape fibre cover in position. 
(3) Assemble overload protector in recess of the end plate and 
secure with clamp and screw. 
(4) Reassemble end plate over shaft securing end plate with bolts 
and nuts. Should the end plate fail to aline by tightening the 
bolts, tap lightly around the flange until it fits snugly against 
the motor frame. 
(5) Replace the motor on the condensing unit as outlined in par 
58 1. CAUTION: DO NOT TIGHTEN MOTOR PULLEY 
ON THE SHAFT UNTIL AFTER THE MOTOR HAS 
BEEN REPLACED ON THE CONDENSING UNIT AND 
MOTOR PULLEY ALINED WITH THE FLYWHEEL. 
I. Removing the Motor for Repairs. To remove the motor for re- 
pairs proceed as follows: 
(1) Remove the belt. (See par 56 b.) 
(2) Remove the motor junction box cover and unsolder the elec- 
trical connections. 
(3) Remove cables from the junction box. 
(4) Remove the 4 nuts and loekwashers from the motor base. 
(5) Motor is now free and can be removed from the machine com- 
partment. 
97 Med. Dept. No. 
1. 
2, 
3■ 
4 • 
5. PR27158 
Figure 65. Removing the overload protector. 
Nomenclature 
Overload fibre cover 
Overload protector clamp screw 
Overload protector clamp 
End plate (pulley) 
Protector, overload 
Med. Dept. No. 
I. SR01032 
Figure 66. Removing motor pulley. 
Nomenclature 
Screw, 5/16-rS x 3/s inch Allen head 
98 (6) Remove the motor pulley with the fan attached from the motor 
shaft by loosening the 2 Allen set screws located in the pulley 
(7) Remove key from motor shaft. 
hub (fig 66, item 1). 
m. Installing the Motor. To install the motor proceed as follows: 
(i) Replace the key on the motor shaft and install the motor pulley 
with fan attached to the motor shaft. (DO NOT TIGHTEN 
THE 2 ALLEN SET SCREWS LOCATED IN THE PUL- 
LEY HUB (FIG 66) UNTIL AFTER THE MOTOR HAS 
BEEN INSTALLED ON THE CONDENSING UNIT 
BASE.) 
(2) Install the motor on the condensing unit base and aline motor 
base with motor bolts. 
(3) Secure motor to the condensing unit base with the 4 lock- 
washers and nuts leaving the nuts loose until the pnlley aline- 
ment has been established. 
(4) Install the belt. (See par 56 c.) 
(5) Aline the pulley with the flywheel and tighten the 2 Allen set 
screws in the pulley hub (fig 66). 
(6) Establish the proper belt tension (see par 56 a) and tighten the 
motor bolts. 
(7) Reinstall the electrical cables and solder the connections mak- 
ing certain that the color code as outlined in the wiring dia- 
gram (fig 5) is followed. 
(8) Tape the soldered connections and reinstall the junction box 
cover. 
(9) Connect the extension cord ping to the source of supply. 
n. Disassembling the Motor tor Repairs. To disassemble the motor 
for repairs proceed as follows (fig 68): 
(1) Remove the motor for repair. (See par 58 I.) 
(2) Remove the 4 end plate bolts and nuts (item 15) and slide the 
bolts from the motor frame. 
(3) Remove the front end plate (item 3) by tapping the flange of 
the plate until it is free and can be removed from the shaft. 
(4) Grasp the shaft and pull the armature forward until it is clear 
of the field coils and motor frame. 
(5) Stand the armature on end (fig 67) and with a screw driver 
depress the governor spring retainer (item g) and remove the 
retainer spring washer (item 10) governor spring retainer 
(item 9) starting spring (item 8) retainer spring extension 
(item 6) and retainer spring washer (item 7). 
99 (6) Remove the brush holder assembly (item 5) and turn the arma- 
ture (item 1) with the commutator end down permitting the 
stator spring retainer (item 4) short-circuit starting necklace 
(item 3) and governor push rods (item 2) to drop out. 
(7) Remove the pulley end plate (fig 68, item 20) by tapping the 
flange until it is free Irom the motor frame. 
(8) Remove screw (fig 68, item 22) retaining overload protector in 
the recess of the plate. 
(9) Remove tape and fibre cover exposing 4 soldered terminals. 
(NOTATION MUST BE MADE OF COLOR CODE OF 
CABLES AND THEIR RESPECTIVE ATTACHED POSI- 
TIONS.) Unsolder terminals and remove wire. 
Med. Dept. No. 
1. gR2ji62 
2. gR2jiy8 
3. $R2yiy6 
4. yR2yiyo 
5. ()R2yiy6 
6. pR2yiy4 
y. pR2yiy2 
8. pR2yi8o 
p. pR2yi86 
10. pR2yj8j 
Nomenclature 
Armature 
Rod, push, governor 
Necklace, starting, circuit, short 
Retainer, spring, stator 
Holders, brush 
Extension, spring, retainer 
Washer, spring, retainer 
Spring, starting 
Retainer, spring, governor 
Washer, spring, retaining 
100 o. Reassembling the Motor. Before reassembling the motor all parts 
should be thoroughly cleaned and inspected. Parts found to be worn 
must be replaced. To reassemble the motor proceed as follows (fig 67). 
(1) Stand armature (item 1) on pulley end of shaft and drop the 2 
governor push rods (item 2) into position. 
(2) Form the short-circuit starting necklace (item 3) around the 
stator spring retainer (item 4) and place it over the shaft into 
position. 
(3) Place brush holder assembly (item 5) over shaft and insert the 
retainer spring extension (item 6) retainer spring washer (item 
7) starting spring (item 8) and governor spring retainer (item 9) 
into the brush holder assembly. 
(4) With a screw driver compress the governor spring retainer 
(item 9) and lock all parts in place by forcing the retainer 
spring washer (item 10) into the groove of the shaft provided 
for this purpose. 
(5) Reassemble the overload protector (fig 68, item 18) by resolder- 
ing the leads to the terminals in accordance with the color code. 
(6) Retape fibre cover into position. 
(7) Reassemble overload protector in the recess of the end plate 
and secure with clamp and screw (fig 68, items 21 and 22). 
(8) Reassemble pulley end plate (fig 68, item 20) on motor frame 
and slide end plate bolts (fig 68, item 15) through the end plate 
and motor frame. Should the end plate fail to aline, tap lightly 
around the flange until it fits snugly against the motor frame. 
(9) Slide the armature into the motor frame by placing the pulley 
end of the shaft into the pulley end plate. Should difficulty be 
experienced in sliding the shaft through the end plate bearing, 
remove the armature and with your finger work the oil wicking 
back to the oil well. 
(10) Replace the front end plate (fig 68, item 3) over the shaft by 
guiding the index plate through the slot in the brush holder. 
(11) Secure the end plate to the motor frame with the end plate 
nuts. Tighten the nuts uniformly by alternating from side to 
side. While tightening the nuts inspect the free movement of 
the armature at intervals to assure correct alinement. Should 
the end plate fail to aline by tightening the bolts, tap lightly 
around the flanges of both end plates until they fit against the 
motor frame. 
(12) Add 10 drops of “OE 10 engine oil” to each oil cup (fig 9, 
item 9). 
(13) Reinstall the motor as outlined in par 581. 
101 Figure 68. Electric motor disassembled. 
102 Med. Dept. No. 
Nomenclature 
Med. 
Dept. No. 
Nomenclature 
/. 
9R27166 
Wick, oil, bearing, front and rear 
J3- 
9R27178 
Rod, push, governor 
2, 
9R2716j 
Bearings, front, armature 
14. 
Motor shims 
3- 
End plate assembly (fro7it) 
I5- 
9R27168 
Bolt and nut, end plate 
4• 
9R27184 
Washer, spring, retaining 
16. 
9R27162 
A r mature 
5- 
9R27186 
Retainer, spring, governor 
n- 
9R27160 
Stator, armature 
6. 
9R27180 
Spring, starting 
18. 
9R2715S 
Protector, overload 
7* 
9R27154 
Brushes, carbon 
19. 
Overload fibre cover 
5. 
9R27176 
Holders, brush 
20. 
End plate assembly (pulley) 
P- 
9R2yiJ4 
Extension, spring, retainer 
21. 
Overload protector clamp 
/o. 
9R27172 
Washer, spring, retainer 
2 2. 
Overload protector clamp screw 
7/. 
9R27176 
Necklace, starting, circuit, short 
23. 
9R27166 
Wick, oil, bearing, front and rear 
12. 
9R27170 
Retainer, spring, stator 
24■ 
9R27169 
Bearing, front and rear, armature 
103 Section XVIII 
Cabinet Repairs 
59. SERVICING THE CABINET 
a. Replacing the Door Gasket. The door gasket is formed into posi- 
tion by adhesion to the 4 sides of the jam faces of the door flange. To 
replace the door gasket proceed as follows: 
(1) Grasp one end of the gasket where it joins at the bottom of the 
door. With a steady pull work the gasket from around the door. 
(2) Remove any particles of the gasket that may have stuck to the 
surface of the door. The surface must be scraped clean in order 
for the new gasket to properly adhere. A dry cleaning solvent 
may be used if necessary. 
(3) Remove the mastic paper from the adhesive surface of the new 
gasket and fit the gasket, gR27oi2, into position around the 
door. 
(4) Secure the gasket to the door by firmly pressing over the entire 
area of the gasket. 
(5) After the gasket has been formed immediately close the door 
and permit the door to remain in a closed position for several 
minutes to assure proper adhesion. 
Figure 69. Adjusting the door latch strike. 
i. Door strike nut 
104 b. Adjusting the Door. Should an inspection of the new gasket in- 
dicate a difficulty in closing or air leakage due to insufficient contact, one 
or both of the following corrections must be made. 
(i) Adjust the door latch strike (fig 6g) by loosening the door strike 
nut (item i) and disengaging the teeth on the bolt head from 
the teeth on the roller strike. By moving the roller strike in 
toward the cabinet an increased door gasket pressure can be 
obtained. After making the adjustment tighten the nut (item 
i) on the door strike. 
Figure 70. Adjusting door hinges. 
i. Door hinge shims 
(2) Adjust the door hinges by inserting or removing a shim in back 
of the hinges (fig 70), Unless the door or door frame is badly 
distorted, the adjustment of the roller strike and hinges should 
provide a satisfactory gasket pressure. 
105 Figure 71. Removing the dial thermometer. 
Med. Dept. No. 
1. pR2‘/o^8 
2. SR01136 
5- 
Nomenclature 
Thermometer, dial 
Screw, j-jo x 14 inch fl. hd. self-tapping 
Dial face ring 
c. Removing the Dial Thermometer. The indicating thermometer 
on the refrigerator door is nonadjustable and if for any reason it becomes 
inoperative the thermometer must be replaced. To remove the thermom- 
eter proceed as follows: 
(1) Turn the indicator dial face ring (fig 71, item 3) with palm of 
hand to release the ring. 
(2) Remove the 3 screws (fig 71, item 2) holding the thermometer 
to the door. 
(3) Remove 6 screws from the thermometer guard located on the 
inside door panel (fig 2, item 2). 
(4) Remove thermometer bulb from retaining clip. 
(5) Straighten thermometer tubing to permit removal of ther- 
mometer through the front of door as shown in fig 71. 
d. Installing the Dial Thermometer. To install the dial thermometer 
proceed as follows; 
(1) Mount the thermometer on the outside of the door panel by 
passing the thermometer bulb through the opening in the 
door (fig 71). 
(2) Secure the thermometer to door with 3 screws (fig 71, item 2). 
(3) Install the indicator dial face ring by alining the pins of the 
ring with the notches on the thermometer and turning the 
106 ring with palm ol hand to a locked position (fig 71, item 3). 
(4) Insert the thermometer bulb into the retaining clip. 
(5) Secure the thermometer guard to the inner cabinet door with 
6 screws. 
Figure 72. Replacing cabinet skid inserts. 
Med. Dept. No. 
1. 9R27042 
2. SRoiI^I 
Nomenclature 
Insert, skid, ivood 
Bolt, x 2I/9 inch carriage 
e. Repairing Damaged Panels. Should the cabinet 01 door panels 
become punctured they must be repaired immediately to prevent moist- 
ure from getting into the insulation. To repair damaged panels proceed 
as follows: 
(1) In the case of a small rupture the hole can be soldered by using 
a large soldering iron. Thoroughly clean the surface of the 
metal before applying flux and solder. 
(2) In the case of a large rupture or tears in the metal, a sheet 
metal patch can be made to cover the damaged area. This 
patch can be held in place by either soldering or sheet metal 
screws. In the latter case a layer of mastic compound should be 
applied beneath the patch to make the joint air tight. After 
soldering on the outside surface the patch must be painted. 
107 f. Replacing the Cabinet Skid Inserts. Should the skids be broken 
or indicate excessive wear they must be replaced. To replace the skids 
proceed as follows. (Fig 72.) 
(1) Tip the cabinet forward or backward to gain access to the 
carriage bolts (item 2). 
(2) Remove the 6 carriage bolt nuts from the unit compartment 
side of skids. 
(3) Drive out the carriage bolts and pry the skid insert (item 1) 
free. 
(4) Install new skid and drive carriage bolts into position. 
(5) Replace the 6 nuts on each skid. 
108 APPENDIX 
Section I 
Preparation for Storage or Shipment 
60. PREPARING THE REFRIGERATION SYSTEM 
o. If the condensing unit is to stand idle for any length of lime the 
unit must be pumped down and the refrigerant isolated in the liquid 
receiver. 
(i) Remove the machine compartment doors and pump down the 
system. (See par 41 a.) 
(2) Inspect all valve stem caps to see that they are in place and 
secure. 
(3) A tag must be attached to the extension cord plug with the 
following notation: “UNIT PUMPED DOWN-3 VALVES 
CLOSED.’’ 
61. PREPARING THE REFRIGERATOR STORAGE COMPARTMENT 
a. Any accumulation of defrost water must be drained from the cabi- 
net to prevent odors while the refrigerator is in storage. Drain the storage 
compartment by opening the drain shutoff valve in the unit compart- 
ment (fig 6, item 5). 
b. Remove all racks, bottles and shelves. If the unit is to be shipped, 
the shelves, racks and bottles must be packed in corrugated paper to pre- 
vent damage to these parts while in transit. 
c. Thoroughly clean the refrigerator compartment with cleaning 
solvent and permit the refrigerator door to stand open until the interior 
of the cabinet is thoroughly dry. Close the refrigerator door and secure 
by inserting the latch pin in the door latch. 
d. Reinstall the machine compartment doors and secure with screws. 
Section II 
References 
62. FIELD AND TECHNICAL MANUALS 
o. Camouflage FM 5-20 
b. Defense against chemical attack FM 21-40 
c. Electrical fundamentals TM 1-455 
d. Decontamination TM 3-220 
109 e. Cleaning, preserving, lubricat- 
ing, and welding materials and similar 
items issued by Ordnance Department 
TM 9-850 
f. Basic maintenance manual 
TM 38-250 
g. Moisture proofing and fungi 
proofing Signal Corps equipment 
TBSIG 13 
63. ABBREVIATIONS 
a. Cubic Centimeters—cc 
b. Revolutions Per Minute—R.P.M. 
c. Society Automotive Engineers—SAE 
d. Alternating Current—A.C. 
e. Cycle—Cy. 
f. Elat Head-11, hd. 
g. Shakeproof—shkp. 
ft. Round Head—R.H. 
i. Hexagon—hex. 
j. Machine Screw—mach. scr. 
110 INDEX 
MAINTENANCE MANUAL 
Subject Page 
Air in the System 
Abbreviations 110 
Purging the Compressor 40 
Purging the Entire System 41 
Purging the Low Side 40 
Altitude 
Adjustments 53 
Effects 22 
Belt—Compressor 
Adjusting 73 
Installing 74 
Removing 74 
Brushes—Motor 
Installing 94 
Removing 94 
Cabinet—Refrigerator 
Adjusting Door 105 
Installing Dial Thermometer 106 
Preparing for Storage 109 
Removing Dial Thermometer 106 
Replacing Door Gasket 104 
Repairing Panels 107 
Replacing Skids 108 
Uncrating 14 
Compressor 
Adding Oil 45 
Balancing the Pressure 39 
Disassembling 79 
Installing 76 
Installing Shaft Seal 78 
Reassembling 86 
Removing 75 
Removing Shaft Seal 77 
Condenser 
Inspecting and Cleaning 26 
Installing 73 
Control System—Explanation 51 
Removing 73 
Control—Heater Thermostatic 
Adjusting 55 
Altitude Adjustments 53 
Installing 57 
Removing 55 
Control—Low Pressure 
Adjusting 57 
Altitude Adjustments 53 
Installing 59 
Removing 58 
111 Subject Page 
Control-Refrigeration Thermostatic 
Adjusting 53 
Altitude Adjustments 53 
Installing 55 
Data 7 
Removing 54 
Defrosting and Inspecting Evaporator 25 
Dehydrator 
Removing Moisture 46 
Electrical Wiring 
Replacing 47 
Controls and Motor 6 
Evaporator 
Defrosting and Inspecting 25 
Installing 50 
Removing 47 
Flywheel—Compressor 
Installing 76 
Removing 76 
Fuseable Plug—Receiver 
Installing 72 
Removing 72 
Gage—Compound 
Installing 33 
Gage—Pressure 
Reading 21 
Installing 34 
Reading 21 
Generator 29 
Head Pressures 
Pressure Temperature Chart. . v 22 
Heater Unit 
Installing 61 
Removing • 59 
Initial Start-up 
Start-up Instructions 14 
Uncrating the Refrigerator 14 
Leak Detector 
Cleaning 37 
Filling 35 
Operating 36 
Use as a Blow Torch 37 
Liquid Receiver 
Use as a Soldering Iron 37 
Installing 71 
Removing 71 
Lubrication 
Compressor 19 
Motor 19 
Precautions 19 
112 Subject Page 
Moisture in the System 
Precaution 22 
Removing 46 
Motor—Electric 
Disassembling Motor 99 
Cleaning Commutator 94 
Installing Armature 95 
Installing Brushes 94 
Installing Motor 99 
Installing Overload Protector 97 
Reassembling Motor 101 
Removing Armature 95 
Removing Brushes 94 
Removing Motor 97 
Removing Overload Protector 96 
Rotation Adjustment 92 
Testing Armature 95 
Opening the System 
Testing Field Coils 95 
Balancing the Pressure 39 
Organizational Maintenance (2nd Echelon) 
Pumping Down 38 
Inspect Condenser 26 
Inspect Evaporator 25 
Lubrication 19,20,45 
Inspect Belt 27 
Inspect Motor 27 
Overload Protector—Motor 
Installing 97 
Removing 96 
Preventive Maintenance 19 
Records 
General Instructions 2 
References 
List of Publications 109 
Refrigerant—Freon 12 
Adding 42 
Removing 43 
Refrigeration Cycle 
Testing for Leaks 37 
Explanation of Cycle 3 
High and Low Side of System 6 
Theory of Refrigeration ;.. 3 
Refrigerator 
Data 7 
Description of Main Parts 7 
General Description 7 
Seal—Compressor Shaft 
Installing 78 
Removing 77 
113 Storage—Preparing lor 
Subject Page 
Cabinet 109 
Suction Line Strainer 
Refrigeration System 109 
Installing 65 
Removing 64 
System—Refrigeration 
Explanation of Cycle 3 
Preparing for Storage 109 
Pumping Down 38 
Purging Air 40 
Testing tor Leaks 
Thermometer—Dial 
Method of Testing 37 
Description 17 
Installing 106 
Removing 106 
Trouble Shooting 
Analysis of Symptoms 20 
Refrigeration Trouble Chart 22 
Uncrating 
Cabinet 14 
Unusual Conditions 
Dust and Sand 18 
High Temperature Conditions 18 
Usual Conditions 
Low Temperature Conditions 18 
Operation 18 
Valve—Discharge Service 
Description and Operation 21 
Installing 70 
Removing 70 
Valve—Liquid Receiver 
Description and Operation 21 
Installing 71 
Removing 71 
Valve—Suction Service 
Description and Operation 20 
Installing 69 
Removing 68 
Valve—Thermostatic Expansion 
Adjusting 63 
Cleaning 63 
Installing 63 
Removing 63 
Valve Plate Assembly—Cylinder Head 
Repairing 67 
Replacing 68 
Testing Reeds 66