ELBOW 4N1041 - Caterpillar

Illustration 1 g01363870
Heating and air conditioning circuit
The components of the heating and air conditioning circuit are the fan speed switch, the air conditioning thermostat switch, the fan motor, the refrigerant pressure switch, the compressor clutch solenoid and the pressurizer fan motor.
Illustration 2 g01034031
Cab
(1) Fan speed switch
(2) Air conditioning control knob
Illustration 3 g01009993
(1) Fan speed switch
(3) Air conditioning thermostat switch
(4) Fan motor
(5) Relay
Illustration 4 g03145616
(6) Pressurizer fan motor
Illustration 5 g01417727
(7) Refrigerant pressure switch
(8) Compressor clutch solenoid With the key start switch in the ON position, 24 V power is supplied from the batteries to circuit breaker 9. Circuit breaker 9 supplies 24 V power to fan speed switch (1), and to relay (5).Fan speed switch (1) is a four position switch which controls the operation of fan motor (4) and pressurizer fan motor (6). When fan speed switch (1) is turned to the LOW, MEDIUM, HIGH position, 24 V power is supplied to air conditioning thermostat switch (3), relay (5), fan motor (4) and pressurizer fan motor (6).Air conditioning thermostat switch (3) controls the required level of cooling and protects the system from over-cooling. When the contacts in air conditioning thermostat switch (3) are closed, 24 V power is supplied to relay (5). Relay (5) will energize and 24 V power will be supplied to refrigerant pressure switch (6). When the air conditioning system is charged with refrigerant, the contacts of refrigerant pressure switch (7) are closed. 24 V power is then supplied to energize compressor clutch solenoid (8) causing the compressor refrigerant pressure to rise.When the refrigerant pressure increases higher than the set value of refrigerant pressure switch (7), the contacts of refrigerant pressure switch (7) will open. 24 V power supply to compressor clutch solenoid (8) will be interrupted. The compressor will not operate and refrigerant pressure will slowly decrease.When the refrigerant pressure decreases to the normal set value of refrigerant pressure switch (7), the contacts of refrigerant pressure switch (7) will close. The compressor will operate.If the refrigerant pressure decreases below the normal operating pressure, the contacts of refrigerant pressure switch (7) will open. 24 V power supplied to compressor clutch solenoid (8) is interrupted and the compressor will not operate. The system will not operate until the system has been serviced.