Engine electrical query

[sunquest]

I have twin cat 3116's which are started by a key switch. to stop the engines you are supposed to depress the separate stop buttons and then turn off the key. Can you not just turn off the key which also stops the engine or is there something I am missing.
Thanks Geoff

 

[Andrew_Fanner]

Stop button probably shuts off the fuel pump or triggers a fuel shut off solenoid.

 

[kelticmad12]

hi
it does turn off the fuel pump
it is a safety feature that is encorparated to stop the fuel just incase of any sparks or surges when turning the key.
You have to remember that the ignition barrel is drawing power from the battery, so sparks can happen.

 

[omega2]

The solenoids that stop the engine are normally open, ie. they allow the engine to run, so you have only to turn the key to operate the starter motor, however the engines are stopped by a lever that closes off the fuel this is actuated by the stop buttons, use them or lose them, cause they will sieze given time.

 

[sunquest]

Thanks once again for your advice. Geoff

 

[sunquest]

That may explain why I have to push the buttons 3 or 4 times to cut the engine.

 

[fisherman]

Some solenoids stay 'fuel on' all the time except when the stop button is held down, to shut off the engine. If you turn off the ignition the engine will continue to run, but the panel goes dead.
Others stay 'fuel off' until the ignition is turned on, so the engine stops when the ignition is turned off. The disadvantage of the second type is if you get a wiring fault to the solenoid the engine stops.

 

[brianrunyard]

Some only need pushing once, but you have to keep them pushed until the engine stops turning, or it will restart.