Thermo King V250 User Manual
V250
TK 40839-1-MM (Rev. 2, 1/99)
©
Copyright
Printed in U.S.A.
1994 Thermo King Corp., Minneapolis, MN, U.S.A.
The maintenance information in this manual covers unit models:
V250 10 (914500) Condenser 10 Plus (085067)
V250 20 Generic (085007) Condenser 10 Plus UK (085068)
V250 LOTEMP (715394) Kit - low temperature (715394)
Condenser 10 (085001) E1000 Evaporator (085031)
Evaporator - Thin Line (085003) E1000E Evaporator (085034)
V250 115/1/60 Standby (085009) V250/E1000E Evaporator (085041)
Evaporator (085005) V250 Converte (085066)
For further information, refer to…
V250 Parts Manual TK 40834
Diagnosing Thermo King Refrigeration Systems TK 5984
Tool Catalog TK 5955
V250 Operating Manual TK 40836
Installation Manual TK 41156
The information in this m anual is provided to as sist owners, operat ors and service peo ple in the proper upk eep
and maintenance of Thermo King units. For detailed descriptions of Thermo King engines, compressors, or
refrigeration systems , see the app ropria te Thermo King Over haul Man ual or Ref rigerat ion Syste ms Main tenanc e
Manual.
This manual is published for informational purposes only and the information so provided should not be considered
as all-inclusive or covering all c ont ing enc ie s. If fu rt her i nformation is required, T h er mo Ki ng C or por ation should be
consulted.
Sale of product shown in this manual is subject to Thermo King’s terms and conditions including, but not limited to,
the Thermo King Limited Express Warranty. Such terms and conditions are available upon request.
Thermo King’s warranty will not appl y to any equipm ent which has been “so r epaired or alter ed outside the manufacturer’s plants as, in the manufacturer’s judgment, to effect its stability.”
No warranties, express or implied, including warranties of fitness for a particular purpose or merchantability, or warr anties ar ising from c ourse o f dea ling or usage of trade, a re made rega rding the information , recommendations, and descriptions contained herein. Manufacturer is not responsible and will not be held
liable in contract or in tort (including negligence) for any special, indirect or consequential damages,
including injury or damage caused to vehicles, contents or persons, by reason of the installation of any
Thermo King product or its mechanical failure.
Recover Refrigerant
At Thermo King, we recognize the need to pr eserve the
environment and limit the potential harm to the ozone
layer that can result from allowing refrigerant to escape
into the atmosphere.
We strictly adhere to a policy that promotes the recovery
and limits the loss of refrigerant into the atmosphere.
In addition, service personnel must be a ware of Federal
regulations concerning the use of refrigerants and the
certification of technicians. For additional informatio n on
regulations and technician certification programs, contact your local THERMO KING dealer.
R-404A R-134a
WARNING: Use ONLY Polyol Ester based refrigeration compressor oil (TK P/N 203-413) in
R-404A and R-134a units.
DO NOT use Polyol Ester based oil in standard Thermo King units.
DO NOT mix Polyol Ester and standard synthetic compressor oils.
Keep Polyol Ester compressor oil in tightly sealed containers. If Polyol Ester oil becomes
contaminated with moisture or standard oils, dispose of properly—DO NOT USE!
WARNING: When servicing Thermo King R-404A and R-134a units, use only those service
tools certified for and dedicated to R-404A or R-134a refrigerant and Polyol Ester
compressor oils. Residual non-HFC refrigerants or oils will contaminate R-404A and R-134a
systems.
Table of Contents
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Maintenance Inspection Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Liquid Injection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Oil Separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Unit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Unit Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Protection Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Optional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Serial Number Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Unit Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Unit Protection Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Unit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Bi-monthly Pre-Trip Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Starting the Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Adjusting the Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
After Start Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Loading Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Post Loading Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Bi-monthly Post Trip Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Electrical Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Unit Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Cab Control Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Selecting the Temperature Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Selecting the Setpoint Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Setpoint Differential Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Testing the Cab Control Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Display Diagnosis Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Thermostat Switch Sequence Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Defrost System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Engine Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Electric Standby Operation (Model 20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Defrost Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
V250 Defrost System and P.C. Board Identification and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
P.C. Board Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Troubleshooting the V250 Defrost System with P.C. Board P/N 41-776 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Troubleshooting the V250 Defrost System with P.C. Boards P/N 41-1619 and P/N 41-1812 . . . . . . . . . . . . . .44
Table of Contents (continued)
Electrical Maintenance (continued)
P.C. Board P/N 41-776 Test Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
P.C. Board P/N 41-1812 and P/N 41-1619 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
M10 (V250/V-090) Cab Control Box Test Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Condenser Fan Pressure Switch (CFPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
AC Components (Model 20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Contactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Overload Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Electric Standby Circuits (Model 20 Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
12 Volt System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Evaporator Heaters (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Refrigeration Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Charging the Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Checking the Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Checking Compressor Oil Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
High Pressure Cutout Switch (HPCO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Low Pressure Cutout Switch (LPCO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Cleanup Procedure for Small Truck Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Refrigeration Service Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Receiver Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
High Pressure Cutout and Condenser Fan Pressure Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Hot Gas Solenoid Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Liquid Injection Solenoid Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Oil Separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Liquid Injection Metering Orifice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Testing the Liquid Injection Solenoid Valve and Metering Orifice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Check Valve Repair (Model 20 Only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Expansion Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Low Pressure Cutout Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Suction Pressure Regulator Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Replacing Refrigerant Hoses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Table of Contents—(continued)
V-250 R-404A Conversion Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Structural Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Unit Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Condenser Fan Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Unit Mounting Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Compressor and Clutch Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
Clutch Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
Clutch Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
Shaft Seal Cover and Shaft Seal: Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Special Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
System Compressor and Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Checking the Oil Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Electrical Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Clutch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Belt Tensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Engine/Compressor Belt and Pulleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Electric Motor/Compressor Belt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Over-the-Road Mechanical Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Road Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Electric Standby Mechanical Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Possible Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93
Electric Standby Service Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
V250 Installation Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Wiring Diagrams and Schematic Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Safety Precautions
GENERAL PRACTICES
1. ALWAYS WEAR GOGGLES OR SAFETY
GLASSES. Refrigerant liquid, refrigeration oil, and
battery acid can permanently damage the eyes (see First
Aid under Refrigeration Oil).
2. Never operate the unit with the compress or discharge
valve closed.
3. Keep your hands, clothing and tools clear of the fans
and belts when the unit is running. This sh ould also be
considered when opening and closing the compressor
service valves.
4. Make sure gauge manifold hoses are in good condition.
Never let them come in contact with a belt, fan motor
pulley, or any hot surface.
5. Never apply heat to a sealed refrigeration system or
container.
6. Fluorocarbon refrigerants, in the presence of an open
flame or electrical short, produce toxic gases that are
severe respiratory irritants capable of causing death.
REFRIGERANT
Although fluorocarbon refrigerants are classified as safe
refrigerants, certain precautions must be observed when
handling them or servicing a unit in which they are used.
When exposed to the atmosphere from the liquid state, fluorocarbon refrigerants evaporator rapidly, freezing anything
they contact.
First Aid
In the event of frost bite, the objectives of First Aid are to
protect the frozen area from further injury, to warm the
affected area rapidly and to maintain respiration.
• EYES: For contact with liquid, immediately flush eyes
with large amounts of water and get prompt medical
attention.
• SKIN: Flush area with large amounts of lukewarm
water. Do not apply heat. Remove contaminated clothing and shoes. Wrap burns with dry, sterile, bulky
dressing to protect from infection/injury. Get medical
attention. Wash contaminated clothing before reuse.
7. Make sure all mounting bo lts are tight an d are of correct length for their particular application.
8. Use extreme caution when drilling holes in the unit.
The holes may weaken structural components, and
holes drilled into electrical wiring can cause fire or
explosion.
9. Use caution when working around exposed coil fins.
The fins can cause painful lacerations.
10. Use caution when working with a refrigerant or refrigeration system in any closed or confined area with a
limited air supply (for example, a truck box or garage).
Refrigerant tends to displace air and can cause oxygen
depletion resulting in suffocation and possible death.
11. EPA Section 608 Certification is needed to work on
refrigeration systems.
• INHALATION: Move victim to fresh air an d use CPR
if necessary. Stay with victim until arrival of emergency medical personnel.
REFRIGERATION OIL
Avoid refrigeration oil contact with the eyes. Avoid prolonged or repeated contact of refrigeration oil with skin or
clothing. Wash thoroughly after handling refrigeration oil to
prevent irritation.
First Aid
In case of eye contact, immediately flush with plenty of
water for at least 15 minutes. Wash skin with soap and
water. CALL A PHYSICIAN.
i
Safety Precautions (Rev 1/99)
ELECTRICAL HAZARDS
High Voltage
When servicing or repairing a refrigeration unit, the possibility of serious or even fatal injury from electrical shock
exists. Extreme care must be used when working with an
operating refrigeration unit. Lethal voltage potentials can
exist on connections in the high voltage tray of the control
box.
Precautions
1. When working on high v oltage circui ts on th e refrig eration unit, do not make any rapid moves. If a tool drops,
do not grab for it. People do not contact high voltage
wires on purpose. It occurs from an unplanned movement.
2. Use tools with insulated handles that are in good condition. Never hold metal tools in your hand if exposed,
energized conductors are within reach.
3. Treat all wires and connections as high voltage until a
meter and wiring diagram show otherwise.
4. Never work alone on high voltage circuits on the refrigeration unit, another person should always be standing
by in the event of an accident to shut off the refrigeration unit and to aid a victim.
5. Have electrically insulated gloves, cable cutters and
safety glasses available in the immediate vicinity in the
event of an accident.
First Aid
IMMEDIATE action must be initiated after a person has
received an electrical shock. Obtain immediate medical
assistance if available.
The source of shock must be immediately removed by
either shutting down the power or removing the victim from
the source. If it is not possible to shut off the power, the wire
should be cut with either an insulated instrument (e.g., a
wooden handled axe or cable cutters with heavy insulated
handles) or by a rescuer wearing electrically insulated
gloves and saf et y gl ass e s. Wh ic hev er me th od i s us ed do no t
look at the wire while it is being cut. The ensuing flash can
cause burns and blindness.
If the victim has to be removed from a live circuit, pull the
victim off with a non-conductive material. Use the victim’s
coat, a rope, wood, or loop your belt around the victim’s leg
or arm and pull the victim off. DO NOT TOUCH the victim.
You can receive a shock from current flowing through the
victim’s body. After separating the victim from power
source, check immediately for the presence of a pulse and
respiration. If a pulse is not present, start CPR (Car dio Pulmonary Resuscitation) and call for emergency medical
assistance. If a pulse is present, respiration may be restored
by using mouth-to-mouth resuscitation, but call for emergency medical assistance.
Low Voltage
Control circuits used in the refrigeration unit are lo w voltage (12 volts dc). This voltage potential is not considered
dangerous, but the large amount of current available (over
30 amperes) can cause severe burns if shorted or ground.
Do not wear jewelry, watch or rings. These items can short
out electrical circuits and cause severe burns to the wearer.
ii
Specifications
General
Compressor Belt driven, multi cylind er, wobble plate type driven
by the truck engine (Model 10) and by the truck
engine or electric motor. (Model 20)
Engine Compressor Oil Charge 6 oz (177 ml) in compressor
Total system: 12 oz (355 ml)
Electric Standby Compressor Oil Charge 6 oz 177 ml) in each compressor
Total system: 24 oz (710 ml)
Compressor Oil Type Polyol Ester P/N 203-413
Defrost Method:
Truck Engine Operation Model 10 Hot gas
Model 20 Hot gas
Electric Standby Model 20 Hot gas
Defrost Timer: Initiation Interval Adjustable, 1 hour to 10 hours
Termination interval 45 minutes
R-134A REFRIGERATION SYSTEM
Refrigerant Charge and Type 5 lb (2.3 kg) R-134a
Defrost Termination Switch: Opens 52 F (11.1 C)
Closes 42 F (5.6 C)
Liquid Line Injection Switch: Opens 200 ± 5 F (93 ± 3 C)
Closes 230 ± 5 F (110 ± 3 C)
High Pressure Cutout Switch: Opens 350 + 25/-0 psi (2413 + 172/-0 kPa)
Closes 200 ± 20 psi (1379 ± 138 kPa)
Low Pressure Cutout: Opens 5 to 11 in. Hg vacuum (-17 to -34 kPa)
Closes 4 to 7 psi (28 to 48 kPa)
Condenser Fan Pressure Switch: Opens 130 ± 10 psi (896 ± 69 kPa)
Closes 180 ± 10 psi (1241 ± 69 kPa)
1
Specifications (Rev 1/99)
R-404A REFRIGERATION SYSTEM
Refrigerant Charge and Type 5 lb (2.3 kg) R-404A
Defrost Termination Switch: Opens 52 F (11.1 C)
Closes 42 F (5.6 C)
Liquid Line Injection Switch: Opens 200 ± 5 F (93 ± 3 C)
Closes 230 ± 5 F (110 ± 3 C)
High Pressure Cutout Switch: Opens 470 ± 7 psi (3241 ± 48 kPa)
Closes 375 ± 38 psi (2585 ± 262 kPa)
Low Pressure Cutout: Opens 5 to 11 in. Hg vacuum (-17 to -34 kPa)
Closes 4 to 7 psi (28 to 48 kPa)
Condenser Fan Pressure Switch: Opens 130 ± 10 psi (896 ± 69 kPa)
Closes 180 ± 10 psi (1241 ± 69 kPa)
ELECTRICAL SYSTEM
Fuses
F1 Condenser Fan Fuse 15 amps
F2 Evaporator Fan Fuse 15 amps
F3 Power Fuse 10 amps
F4 Control Circuit Fuse 3 amps
Battery Circuit Breaker 40 amps
Transformer Fuse 4 amps (10 amps in 115/1/60 units)
F5 Defrost Circuit Fuse 1 amp
F7 Transformer Fuse 10 amps
Condenser and Evaporator Fan Motors
Voltage Horsepower
12 Vdc 0.17 0.12 1750-2000 6-9 amps
Hot Gas Solenoid and Liquid Injection Solenoid Coils
Voltage Current Resistance
Power Rating
in Kilowatts
rpm Full Load Current
12 Vdc 0.6-0.8 amps 15-19 ohms
2
Electrical Standby Compressor Motors
Specifications (Rev 1/99)
Voltage Phase Frequency Horsepower Kilowatts
115 Vac 1 60 Hz 1.5 1.1 1750 15.0 16.0
230 Vac 1 60 Hz 2.0 1.5 1755 8.6 9.5
220 Vac 1 50 Hz 1.7 1.3 1460 10.0 11.0
230 Vac* 3 60 Hz 2.0 1.5 1695 6.8 3.5**
220 Vac* 3 50 Hz 1.6 1.2 1430 6.0 3.5**
400 Vac* 3 50 Hz 1.6 1.2 1405 3.2 3.5
* Motor can be wired for all three voltages.
**Overload relay monitors 1/2 motor windings on 220 and 230.
Optional Electri c Heaters
Voltage Power Rating Watts Current Resistance
230 Vac 1500 6.5 amps 35.3 ohms
400 Vac 1134 2.8 amps 141.1 ohms
BELT TENSION (Using Tool P/N 204-427)
Engine/Compressor 35
Electric Motor/Compressor 57
Field Reset
Full Load
rpm
Full Load
Current
(amps)
Overload
Relay Setting
(amps)
3
4
Maintenance Inspection Schedule
First Week Inspection and Maintenance
AFTER FIRST WEEK OF OPERATION:
• Check the belt tension
• Tighten the unit mounting bolts
• Check the refrigerant level
Bi-monthly Annually Inspect/Service These Items
ELECTRICAL
••
••
••
•
•
•
••
•
••
••
••
••
••
••
Check defrost initiation and termination.
Check thermostat cycle sequence.
Check operation of protection shutdown circuits.
Check thermostat and thermometer calibration in 32 F (0 C) ice-water bath.
Inspect wire harness for damaged wires or connections.
Inspect/replace DC fan motor brushes.
REFRIGERATION
Check refrigerant level.
Replace dehydrator.
STRUCTURAL
Visually inspect unit and refrigerant hoses for fluid leaks.
Visually inspect unit for damaged, loose or broken parts.
Clean defrost drains.
Inspect belts for condition and proper tension (belt tension tool P/N 204-427).
Clean entire unit including evaporator coil and condenser coil.
Check all unit mounting bolts, brackets, lines, hoses, etc.
5
6
Unit Description
The Thermo King V250 is a truck refrigeration system that
is designed for low and medium temperature applications
on medium-sized trucks. There are two basic models:
• Model 10: C o ol a nd de fr os t o n en gin e -dr iv e n c o mp re ssor operation.
• Model 20: Cool and defrost on both truck enginedriven and electric standby compressor operation.
The system consist of three separate assemblies: the condenser, the evaporator, and the compressor.
The condenser has a unique design that allows it to be
mounted horizontally or vertically, on the roof or on the
front of the truck box.
The evaporator is mounted inside the truck box. Funnel and
thin-line evaporators are available. The funnel evaporator
mounts on the ceiling or the front wall. The thin-line evaporator mounts on the front wall.
The electric standby compressor is connected in parallel
with the engine-driven compressor. The engine compressor
is driven by a belt from the engine. Th e standb y compres sor
is driven by a belt from the electric motor. Both compressors use the same refrigeration system circuit. Check valves
isolate one compressor from the other during operation.
Compressor operation is controlled by the thermostat,
which energizes the compressor clutch during engine operation or starts the electric motor and energizes the compressor clutch on electric standby operation. The refrigeration
system is protected by a high pressure cutout switch and a
low pressure cutout switch.
The control circuits operate on 12 volts dc supplied by the
truck battery for over-the-road operation. On standby operation, the power is rectified from an ac transformer.
The cab control box is mounted in the truck cab. It contai ns
the On-Off key, Manual Defrost key, thermometer, thermostat, and indicator lights.
Liquid Injection System
Condenser and Evaporator Configurations
The compressor is mounted on and driven by the truck
engine. Refrigeration hoses or lines are used to connect the
condenser, the evaporator and the compressor. Model 20
units have another compressor and an electric motor
mounted in the condenser section for electric standby
operation.
If the discharge gas leaving the engine driven compressor
reaches a temperature of 230 ± 5 F (110 ± 3 C), the liquid
injection switch closes, providing voltage to the liquid injection solenoid. The solenoid opens a valve, allowing liquid
refrigerant to flow from the liquid line near the receiver outlet valve to the metering orifice attached to the suction fitting at the compressor. As the refrigerant passes through the
metering orifice it expands and evaporates, cooling the suction gas entering the compressor. This cooling effect is
transferred to the dischar ge gas lea ving th e compresso r from
the adjacent cavity in the compressor head. When the discharge gas is cooled to 2 00 ± 5 F (9 3 ± 3 C), the liquid injection switch opens, the liquid injection solenoid v alve closes
and refrigerant no longer flows through the liquid injection
system.
7
Unit Description (Rev 1/99)
Oil Separator
An oil separator is a standard feature. It separates compressor oil from refrigerant vapor and returns the oil to the compressor through the oil fill hole by using a special adapter.
The oil separator helps provide positive oil return at high
compressor speeds and low operating temperatures. This
feature enhances compressor lubrication and extends compressor life. Units built after November 1996 will be located
in the condenser section. Refer to photo on page 12 and
drawing on page 61.
UNIT OPERATION
These units shift between cool, null, and heat (optional) to
maintain the box temperature at the thermostat setpoint.
The operating modes are: cool, null, heat (optional), and
defrost.
Engine Operation
The thermostat controls the operation of the unit by energizing and de-energizing the power relay and the heat relay.
The thermostat places the unit in cool by energizing the
power relay. The thermostat places the unit in null by deenergizing all the relays. The thermostat places the unit in
heat by energizing the heat relay .
When the power relay is energized, power flows to energize
the fan relay and the compressor clutch through normally
closed contacts in ER2.
When the heat relay is energized, it closes contacts that
energize the fan relay, the water pump, and the water valve.
When the fan relay is energized, it closes contacts that energize the condenser and evaporator fans. The condenser fan
is also controlled by the condenser fan pressure switch.
This normally open switch monitors the compressor discharge pressure. When the discharg e pressure rises to 180 ±
10 psi (1241 ± 69 kPa), the switch closes and energizes the
condenser fan. When the discharge pressure drops to 130 ±
10 psi (896 ± 69 kPa), th e swit ch opens and de-ener gi zes the
condenser fan.
Electric Standby Operation
During electric standby operation, the thermostat controls
the operation of the unit by energizing and de-energizing the
power relay, the electric relays, and the heat contactor. The
thermostat places the unit in cool by energizing the power
relay and the electric relays.
The thermostat places the unit in null by de-energizing all
the relays and contactors. The thermostat places the unit in
heat by energizing the heat contactor.
When the power relay and the electric relays are energized,
they close contacts that energize the fan relay, the motor
contactor, and the electric standby compressor clutch.
When the heat contactor is energized, it energizes the electric evaporator heaters and the fan relay.
Cool
The thermostat shifts the unit to cool at temperatures more
than 5.4 F (3 C) above the thermostat setpoint. The thermostat keeps the unit running in cool until the temperature falls
to the thermostat setpoint.
During engine operation the engine compressor and the
evaporator fans operate while the unit is in co ol. During
electric operation, the electric motor, the electric standby
compressor, and the evaporator fans operate while the unit
is in cool.
Null
The thermostat shifts the unit from cool to null at the thermostat setpoint. The thermostat shifts the unit from null to
heat at 3 F (1.7 C) below the thermostat setpoint. The thermostat shifts the unit from heat to null at 2.4 F (1.3 C) above
the thermostat setpoint. The thermostat shifts the unit from
null to cool at 5.4 F (3 C) above the thermostat setpoint.
8
Heat (Optional)
The thermostat shifts the unit to heat at temperatures more
than 3 F (1.7 C) below the thermostat setpoint. Th e therm ostat keeps the unit running in heat un til the temp erature ris es
to 2.4 F (1.3 C) above the thermostat setpoint. During
engine operation, the water pump and the evaporator fans
operate while the unit is in heat.
During electric operation, the evaporator heaters and the
evaporator fans operate while the unit is in heat.
Defrost
The defrost cycle can be initiated any time the evaporator
coil temperature is below 42 F (5.6 C). Defrost is initiated
automatically by the defrost timer, or manually by pressing
the Manual Defrost switch.
Unit Description (Rev 1/99)
AGA329
Initiating defrost energizes the defrost relay. This energizes
the hot gas solenoid to route hot gas to the evaporator, and
de-energizes the fan relay to stop the evaporator and condenser fans.
The unit runs in defrost until the evaporator coil temperature rises to 52 F (11.1 C), causing the defrost termination
switch to open. This de-energizes the defrost relay and terminates defrost. If the defrost termination switch does not
open in less than 45 minutes, the defrost timer will terminate the defrost cycle 45 minutes after is was started.
0Setpoint
1 Temperature Drop
2 Temperature Rise
3Cool
4Null
5 Heat (Optional)
(1) Shifts from Null to Cool if not previously in Heat
(2) Shifts from Null to Heat if not previously in Cool
Thermostat Algorithm
UNIT FEATURES
• Digital Thermometer
• Electronic Thermostat
• Defrost Timer
• Hot Gas Defrost
• Defrost Termination Switch
• Liquid Injection System
9
Unit Description (Rev 1/99)
• Manual Defrost Key
• Suction Pressure Regulator
• Oil Separator
• Six Cylinder Compressor
• R-134a
Unit Features (continued)
• Standby Electric Motor and Six Cylinder Standby
Compressor (Model 20 only)
• Refrigerant Flow Controlled Between Compressors by
Discharge Check Valve (Model 20 only)
PROTECTION FEATURES
• Control Circuit Fuses
• Refrigerant High Pressure Cutout
• Refrigerant Low Pressure Cuto ut
• Heat, Truck Engine and Electric Standby Heater St rips
(Model 20)
• Paint, Special Color
• 24 V dc Converter
• R-404A Dealer Installed
SERIAL NUMBER LOCATIONS
Condenser: Roadside.
Evaporator: Roadside panel.
Compressor: Nameplate on compressor body.
Standby Motor: Nameplate on motor.
• Refrigerant High Pressure Relief Valve
• Power Cord Warning Light (in Cab Control Box)
• Overload Relay Protection for Electric Standby Motor
(Model 20 o nl y)
• Transformer Fuses (Model 20 only)
OPTIONAL FEATURES
• Electric Motors (Model 20 only)
115 Volt/1 Phase/60 Hz
220 Volt/1 Phase/50 Hz
230 Volt/1 Phase/60 Hz
220 Volt/3 Phase/50 Hz
230 Volt/3 Phase/60 Hz
400 Volt/3 Phase/50 Hz
• Heat, Truck Engine (Model 10)
10
Unit Description (Rev 1/99)
AGA339
Vertical Mounted Condenser (Early Model)
AGA673
Vertical Mounted Condenser (Later Model)
11
Unit Description (Rev 1/99)
12 4356
7
14
12
9101113
1. High Voltage Box 8. Oil Separator
2. Compressor 9. Liquid Injection Solenoi d
3. Hot Gas Solenoid (Behind Fan Blade ) 10. Drier
4. Hourmeters Location (Optional) 11. Condenser Coil
5. Low Voltage Box 12. Check Valve Assembly
6. Condenser Fan 13. Motor (Model 20 only)
7. Receiver Tank 14. 24 Volt Converter
Condenser Components—Front/Top View (Starting 1997)
8
AEA825
12
Unit Description (Rev 1/99)
1. Expansion Valve 3. Fan Motor
2. Thermostat Sensor 4. Suction Pressure Regulator
Funnel Evaporator
13
Unit Description (Rev 1/99)
1. Thermostat Sensor 4. Expansion Valve
2. Heat Exchanger 5. Evaporator Coil
3. Suction Pressure Regulator
Thin-Line Evaporator
14
Unit Description (Rev 1/99)
1
AEA667
2
1. Relays 2. PC Board
Low Voltage Box—Pre-1996
15
Unit Description (Rev 1/99)
9
8
7
1
6
5
4
3
AEA660
1. Transformer 6. Transformer Fuse
2. Motor Start Capacitors 7. Overload Relay
3. Motor Start Relay 8. Motor Contactor
4. DC Power Filter Capacitor 9. Heat Contactor (Optional)
5. Motor Run Capacitor
2
High Voltage Box—Pre-1997
16
Unit Description (Rev 1/99)
1
9
8
7
6
AEA826
2345
1. Transformer 6. Transformer Fuse
2. Motor Start Capacitors 7. Overload Relay
3. DC Power Filter Capacitor 8. Motor Contactor
4. Motor Run Capacitor 9. Heat Contactor (Optional)
5. Motor Start Relay
High Voltage Box—Starting 1997
17
Unit Description (Rev 1/99)
1
2
3
8
4
5
7
6
1. D.C. Power Filter Capacitor 5. Transformer
2. Motor Starting Capacitor 6. Motor Contactor
3. Motor Start Relay 7. Fuse and Fuseholder
4. Motor Run Capacitor 8. Motor Protector
High Voltage Box - Typical for Single Phase P97
AGA340
18
Unit Description (Rev 1/99)
1
2
3
5
4
AGA345
1. D.C. Power Filter Capacitor 4. Motor Contactor
2. Transformer 5. Fuse and Fuse Holder
3. Overload Relay
High Voltage Box - Typical fo r 3 Phase P97
19
Unit Description (Rev 1/99)
123 4 5 6 7
91011121314
1. Power Cord Indicator 8. Thermostat Dial
2. Running Indicator 9. Setpoint Key
3. Defrost Indicator 10. AC Overload Indicator
4. Heat Indicator 11. Digital Display
5. Cool Indicator 12. Manual Defrost Key
6. Celsius Indicator 13. On-Off Key
7. Fahrenheit Indicator 14. On Indicator
Cab Control Box—M10 Pre-1997
8
AEA661
20
Unit Description (Rev 1/99)
NOTE: The M13 and M10 cab boxes a re identified by th e position of the d efrost indicator li ght. On the M13 cab box the
defrost indicator light is po sitioned on the def rost key. On the M10 cab box t he defrost indica tor light is pos itioned left of
the digital display. Refer to the following illustrations. Refer to Service Bulletin 177.
AEA835
1. Defrost Indicator Light
M13 Cab Box—TK No. 45-1780
1. Defrost Indicator Light
M10 Cab Box—TK No. 45-1705
AEA836
21
22
Loading...