- 12 -
completing the circuit from the other Battery to 1T Terminal 9 or 10. The engine now cranks on the
alternate battery power. If the engine fails to start, this cycle repeats for a total of six (6) crank
periods alternating batteries each time.
After six (6) crank periods the "Failed to Start" relay 3CR is energized. Its N.O. contacts
(terminals 6 and 9) close to energize the alarm relay 13CR through diode D30. Relay 3CR N.C.
contacts (terminals 1 and 7) open to stop the cranking and another set of N.C. contacts (terminals 3
and 9) opens to drop out the Fuel Solenoid relay 6CR. A set of 3CR N.O. contacts (terminals 7 and
4) closes to light the "Failed to Start" light.
If the engine starts, the engine speed switch applies battery voltage to 1T Terminal 2 and energizes
Engine Running relay 9CR. 9CR N.C. contacts (terminals 1 and 7) open and cut off power to the
cranking circuits. 9CR contacts connected to 1T Terminals 20, 21, 22, 23, 24, and 25 are used for
remote indications of engine running.
The engine "Low Oil Pressure" light is powered only when the Controller is in the run mode and
6CR contacts (terminals 9 and 6) are closed or when the selector switch is in the "Man" position.
This prevents the "Low Oil Pressure" light from coming on when the Controller is in "Auto" and
in the standby mode with the engine not running. It also allows the light to come on when the engine
is cranking, while the oil pressure switch is still closed, thus, giving an indication that the oil pressure
switch is working. When the engine starts, battery power is applied to one side of the Oil Pressure
Alarm Delay Timer circuit on the main logic board. If the oil pressure is low, the oil pressure switch
is closed and completes the circuit through 1T Terminal 4 and D45 to K1. If the oil pressure remains
low the oil pressure timer will time out and relay contacts of K1will close and energize the alarm
relay 13CR through D27. The "Low Oil Pressure" light will remain on as long as the oil pressure
switch is closed. Normally, the oil pressure comes up as soon as the engine starts, so the oil pressure
timer does not remain energized long enough to time out.
The water temperature switch is N.O., and closes on high engine water temperature. When it closes
it operates the water temperature light on the Controller through 1T Terminal 5 and energizes the
alarm relay through D31.
If an overspeed condition should develop while the engine is running, a speed switch on the engine
closes and puts battery voltage on 1T Terminal 3. This energizes the Overspeed relay 15CR through
diode D47. 15CR locks in on its own N.O. contacts (terminals 4 and 7) through diode D46, and,
thus, remains energized until reset by switching the Controller to "Off". 15CR N.O. contacts
(terminals 6 and 9) close to turn on the "Overspeed" light and energize 13CR through diode D28.
15CR N.C. contacts (terminals 3 and 9) open to de-energize the auto start relay and disable the
cranking circuits and shutdown the engine.
If the Controller is wired for "Automatic Stop" and the water pressure has returned to normal, 8CR
will drop out after the ERT times out and its contacts open. The ERT timer starts timing when 8CR
is energized by the closure of N.O. contacts (terminals 5 and 8) to the ERT Coil. If the Controller is
wired for "Manual Stop", 8CR will remain locked in until the control switch is turned to "Off" or
the "Stop" pushbutton is pressed. The ERT is installed to assure that the engine runs for a minimum
time, and should be set to at least 30 minutes. If the pressure switch remains closed for a longer
period than set on the ERT, the ERT will time out but 8CR will remain energized through the
pressure switch until the pressure switch contacts open.
The alarm circuit consists of a bell mounted on the outside of the enclosure, and is controlled by
13CR N.O. contacts (terminals 6 and 9). 13CR is energized by one of the following failures:
1. Engine Overspeed
2. Low Oil Pressure
3. High Water Temperature
4. Loss of Battery Charger Output
5. A Battery is Missing/Disconnected
6. Failed to Start
7. Battery Failure
8. Low Fuel Level (Option F)
9. Pump Room Alarm (Option K)
To Next Page
Loading...
Need help?
General
