END BIT (L.H. 1.125" TH.) 4J8850 - Caterpillar

Circulation of Coolant
Illustration 1 g00883536
Schematic of the coolant flowUpon energizing the heating system, coolant is drawn from a low point in the engine's cooling system. The coolant is circulated by a centrifugal pump through the heating tank. The coolant exits the tank through a switch that senses the fluid flow (flow switch). The heated coolant is pumped to the top of the engine. The coolant flows downward through the engine for recirculation.During engine operation, a solenoid valve at the heater's outlet limits the coolant's backflow. The solenoid also limits the backflow when the heating system is shut down.Circulation of Lube Oil
Illustration 2 g00883468
Schematic of circulation of lube oilUpon energizing the system, engine oil is drawn from the engine oil sump. The engine oil is circulated by a gear pump through the heating tank. The heated engine oil exits the tank through a switch that senses the fluid flow (flow switch). The engine oil is routed back to the engine oil sump for recirculation.A check valve at the heater's outlet limits the backflow when the heating system is shut down.Electrical System Operation
Illustration 3 g01365810
Operational schematic of the electrical system (1) Customer supplied circuit breaker (2) Fuse (3) Transformer (4) Control relay (5) Control box's on/off switch (6) On/off indicator (7) Solenoid (8) Time delay relay (9) Coil for the pump motor's contactor (10) Pump motor's contactor (11) Pump motor's protective switch (12) Pump motor (13) Flow switch (14) Pump motor's protective switch's auxiliary contacts (15) Thermostat (16) Coil for the heating element's contactor (17) Heating element's contactor (18) Heating elementNote: Except for the few differences that are noted, the jacket water heater and the lube oil heater operate in the same manner. In combined heating systems, the jacket water heater and the lube oil heater can be operated independently.The requirement for voltage and frequency depends on the particular system. The different systems require 380 to 480 volts and 50 or 60 Hz.Customer supplied circuit breaker (1) protects the system from electrical overload. The 380 to 480 volts are provided to transformer (3), to pump motor (12), and to heating element (18) .Note: The fuses at the different locations have different ratings.Fuses (2) protect transformer (3) from electrical overload.Although the pump motor and the heating element require high voltage (380 to 480 volts), the heating system's control is powered with lower voltage. Transformer (3) reduces the high voltage to 110 to 120 volts in order to operate the system. After the transformer, fuse (2) protects the 110 to 120 volt system from electrical overload.Before the system can be operated, control relay (4) must close the circuit. The control relay is operated via customer supplied 24 volts. The control relay opens the circuit during engine operation and the control relay closes the circuit when the engine is shut down.When on/off switch (5) on the control box is switched, the system is powered up and indicator (6) on the control box illuminates.Note: Solenoid (7) is only installed on the outlet for the jacket water heater.