156Service Manual – CS7010™ 28 - Engine System, Diesel
Engine Protection
The engine will be automatically shut down by the main machine controller if the engine overheats or oil
pressure is lost.
When the engine is running, the main machine controller sends a 12 volt power supply out on connector J3
pin number 9 to power up the governor controller When the main machine controller wants to shut down the
engine, it removes this power supply to the governor controller. When the governor loses the power supply it
causes the engine to shut down.
Over Temperature Shutdown
Here is how the engine over temperature shutdown works. To monitor engine temperature, the main
machine controller sends a voltage through an internal resistor out connector J7 pin number 5 on the green
wire with a yellow stripe to the engine coolant temperature switch. The switch is normally open. When the
engine overheats the switch closes. The closing of the switch connects the voltage source to ground which
drops the voltage seen by the main machine controller to nearly 0 volts. An engine temperature fault occurs
when the coolant sensor switches to ground. This fault will be displayed on the Control panel. In response to
the overheat condition, the main machine controller waits ve seconds to give the operator time to park the
machine then removes the power supply going out connector J3 pin number 9 from the APECS 3000
Governor controller, which causes the engine to shut down.
To Next Page
Loading...
