Shutoffs and alarms are electrically operated or mechanically operated. The operation of all electric shutoffs and alarms utilize components which actuate switches in a sensing unit.
Shutoffs are set at critical levels for the following items: operating temperature, operating pressure, operating level and operating rpm. The particular shutoff may need to be reset before the engine will start.
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Always determine the cause of the engine shutdown. Make necessary repairs before attempting to restart the engine. |
Be familiar with the following items:
- Types and locations of shutoff
- Conditions which cause each shutoff to function
- The resetting procedure that is required to restart the engine
Alarms consist of a switch and a contactor. The switches are wired to the contactors. The contactors activate alarm circuits in an annunciator panel. Your engine may be equipped with the following switches:
Engine oil pressure - The engine oil pressure switch indicates when oil pressure drops below rated system pressure.
Coolant level - The low coolant level switch indicates when the coolant level is low.
Coolant temperature - The coolant temperature switch indicates high jacket water coolant temperature.
Note: The sensing element of the coolant temperature switch must be submerged in coolant in order to operate.
Engines may be equipped with alarms in order to alert the operator when undesirable operating conditions occur.
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When an alarm is activated, corrective measures must be taken before the situation becomes an emergency in order to avoid possible engine damage. |
If corrective measures are not taken within a reasonable time, engine damage could result. The alarm will continue until the condition is corrected. The alarm may need to be reset.
A switch may be installed in the alarm while the engine is stopped for repairs. Before the engine is started, ensure that the switch is moved to the ON position and that the warning lights are flashing. The engine will not be protected if the switch is left in the OFF position.
Testing the Shutoff and Alarm System
Most control panels are equipped with a lamp test switch. Turn the switch to the ON position in order to check the indicator lights for proper operation. Replace defective bulbs immediately.
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During testing, abnormal operating conditions must be simulated. Perform the tests correctly in order to help prevent possible engine damage. |
Refer to the Troubleshooting Guide for more information on testing procedures or consult your Cat dealer.