CAP 6K6977 - Caterpillar

Pressure Switch
These type pressure switches are used for several purposes and are available with different specifications. They are used in the oil system and in the fuel system. One use of the switch is to open the circuit between the battery and the rack shutoff solenoid after the oil pressure is below the pressure specifications of the switch. It also closes when the engine starts.Another use of the switch is to close and activate the battery charging circuit when the pressure is above the pressure specification of the switch. It also disconnects the circuit when the engine is stopped.Some switches of this type have three terminal connections they are used to do two operations with the one switch, they open one circuit and close another with the single switch.
PRESSURE SWITCHContactor Switch For Oil Pressure
Micro Switch Type
The contactor switch for oil pressure is to give protection to the engine from damage because of low oil pressure. When oil pressure lowers to the pressure specifications of the switch, the switch closes and activates the rack shutoff solenoid or connects the magneto to ground and closes the gas valve on gas engines.On automatic start/stop installations, this contactor switch closes to remove the starting system from the circuit when the engine is running with normal oil pressure.This contactor switch for oil pressure can be connected in a warning system for indication of low oil pressure with a light or horn.
CONTACTOR SWITCH FOR THE OIL PRESSURE (Micro Switch Type)
1. Locknut. 2. Adjustment screw. 3. Spring. 4. Arm. 5. Spring. 6. Bellows. 7. Latch plate. 8. Button for micro switch. 9. Arm. 10. Projection of arm.As pressure of the oil in bellows (6) becomes higher, arm (4) is moved against the force of spring (3). When projection (10) of arm (4) makes contact with arm (9), pressure in the bellows moves both arms. This also moves button (8) of the micro switch to activate the micro switch.Some of these contactor switches have a "Set For Start" button. Pushing in the button, puts the micro switch in the RUN position. This is done because latch plate (7) holds arm (9) against button (8) of the micro switch and the switch operates as if oil pressure is normal. When the engine is running, oil pressure is in bellows (6) and arm (4) moves to make the arm come in contact with latch plate (7). The "Set For Start" button is released by spring (5). This puts the contactor switch in a ready to operate condition to stop the engine when the oil pressure is low.Earlier Type Switch
Early contactor switches for oil pressure have a control knob (1). The knob must be turned (reset) every time the engine is stopped. Turn the knob counterclockwise to the OFF position. The knob moves to the RUN position when the oil pressure is normal.
CONTACTOR SWITCH FOR OIL PRESSURE (Earlier Type)
1. Control knob.Shutoff Valve For Water Temperature
The shutoff valve for water temperature is connected in an oil line from the mechanical