SWITCH AS 2N7744 - Caterpillar

Illustration 1 g00468063
Right Side Of Engine
(1) Emergency manual shutoff knob
(2) Reset knob
(3) Hydraulic valve for the engine oil The air shutoff is used to shut off the air supply to the engine in addition to the fuel in the event of an emergency shutdown. Only use the air shutoff for emergency shutdowns. It is very important for both air shutoffs to be manually reset to the open position prior to restarting the engine if an emergency shutdown has occurred. There is a reset knob (2) on each side of the engine.The air shutoff consists of a spring loaded butterfly valve which is hydraulically actuated through the use of engine oil pressure. There are two ways to close the air shutoff in an emergency. An electrical signal from the ECM will actuate the solenoid on the hydraulic valve for the engine oil. The solenoid is mounted on the right side of the engine. The air shutoff can be activated manually. This is done by pulling the red emergency manual shutoff knob (1) which is on each side of the engine.
The engine air shutoff system will only work effectively if BOTH air shutoffs are closed. If the air shutoff is manually actuated, BOTH air shutoffs must be independently activated.