Ingersoll-Rand Thermo King V-520 10, Operator'S Manual, Page: 24 / 74

Unit Description
24
Protection Features
High Pressure Transducer: The high pressure transducer
is a pressure sensitive device. It is located in the discharge line
near the oil separator or the discharge check valve. If the
discharge pressure rises above the transducer’s opening
pressure, the ECM opens the circuit to the compressor clutch to
stop the unit.
Low Pressure Cutout Switch: The Low Pressure Cutout
Switch is a pressure sensitive switch located in the suction line.
If the pressure falls below acceptable limits, the switch opens
the LPCO/CH circuit. This signals the ECM to open the circuit
to the compressor clutch to stop unit operation.
Fuses
Fuse 1: Protects the Power Supply Circuit.
Fuse 2: Protects the Condenser Fan Motor (CFM1).
Fuse 3: Protects the Evaporator Fan Motor (EF1).
Fuse 4: Protects the Evaporator Fan Motor (EF2).
Fuse 5: Protects the Compressor Clutch 1 (CCL1), Liquid
Injection Switch (LIS), Liquid Injection Valve (LIV), Host Hot
Gas Defrost Solenoid Valve (PS1), Compressor Motor
Contactor (CC), 26A Circuit to Heat Option
Fuse 6: Protects the Condenser Fan 1, 2 (CFM1and CFM2).
Fuse 7: Protects the Condenser Fan Motor (CFM2).
Fuse 8: Protects the Remote Liquid Solenoid Valve (PS2), Host
Liquid Solenoid Valve (PS3), Remote Hot Gas Defrost
Solenoid Valve (PS4), and Suction Bypass Solenoid (PS6).
Fuse 9: Protects theEvaporator Fan Motor (EFM3)
Fuse 10: Protects theEvaporator Fan Motor (EFM4)
Fuse 11: Protects the Defrost Drain Heaters (DH1 and DH2)
Fuse 20: Transformer Input (L1)
Fuse 21: Battery Relay (Located in 2 wire near battery)
Unit Description
24
Protection Features
High Pressure Transducer: The high pressure transducer
is a pressure sensitive device. It is located in the discharge line
near the oil separator or the discharge check valve. If the
discharge pressure rises above the transducer’s opening
pressure, the ECM opens the circuit to the compressor clutch to
stop the unit.
Low Pressure Cutout Switch: The Low Pressure Cutout
Switch is a pressure sensitive switch located in the suction line.
If the pressure falls below acceptable limits, the switch opens
the LPCO/CH circuit. This signals the ECM to open the circuit
to the compressor clutch to stop unit operation.
Fuses
Fuse 1: Protects the Power Supply Circuit.
Fuse 2: Protects the Condenser Fan Motor (CFM1).
Fuse 3: Protects the Evaporator Fan Motor (EF1).
Fuse 4: Protects the Evaporator Fan Motor (EF2).
Fuse 5: Protects the Compressor Clutch 1 (CCL1), Liquid
Injection Switch (LIS), Liquid Injection Valve (LIV), Host Hot
Gas Defrost Solenoid Valve (PS1), Compressor Motor
Contactor (CC), 26A Circuit to Heat Option
Fuse 6: Protects the Condenser Fan 1, 2 (CFM1and CFM2).
Fuse 7: Protects the Condenser Fan Motor (CFM2).
Fuse 8: Protects the Remote Liquid Solenoid Valve (PS2), Host
Liquid Solenoid Valve (PS3), Remote Hot Gas Defrost
Solenoid Valve (PS4), and Suction Bypass Solenoid (PS6).
Fuse 9: Protects theEvaporator Fan Motor (EFM3)
Fuse 10: Protects theEvaporator Fan Motor (EFM4)
Fuse 11: Protects the Defrost Drain Heaters (DH1 and DH2)
Fuse 20: Transformer Input (L1)
Fuse 21: Battery Relay (Located in 2 wire near battery)