14616M Mariner DAMPER

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 engineAir Shutoff Solenoid (If Equipped)
This optional solenoid is located on top of the engine. The air shutoff is part of the air inlet system. When the solenoid is activated, the solenoid mechanically shuts off the inlet air to the engine. The solenoid can be activated only by the overspeed switch or by the emergency stop push button (ESPB). The cause of the shutoff should be determined before the engine is restarted.Fuel Shutoff Solenoid
The fuel shutoff solenoid is located on the governor or the fuel shutoff solenoid is located on the fuel injection pump. When the fuel shutoff solenoid is activated, the solenoid moves the fuel rack "OFF". The fuel shutoff solenoid moves the fuel rack directly or the fuel shutoff solenoid moves the fuel rack through the governor.Overspeed Shutoffs
Illustration 1 g00293335
(1) Magnetic pickup
(2) Flywheel housing The magnetic pickup senses the passage of the teeth that are on the flywheel ring gear. The Electronic Overspeed Switch is set at 118 percent of the rated engine speed. If the engine speed increases above the overspeed setting, the magnetic pickup will sense the overspeed. A signal is sent to the Electronic Overspeed Switch. The Electronic Overspeed Switch activates both the air shutoff solenoid (if equipped) and the fuel shutoff solenoid.The shutoffs must be reset before the engine will restart. The air shutoff lever that is located at the top of the air inlet housing must be manually reset. The cause of the overspeed must be determined before the engine is restarted.Alarms
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.
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 worn bulbs immediately.
During testing, abnormal operating conditions must be simulated. Perform the tests correctly in order to help prevent possible engine damage.
Refer to the Service Manual for more information on testing procedures or consult your Caterpillar dealer.Testing of the Overspeed Switch
Illustration 2 g00291056
Electronic Overspeed Switch
The overspeed shutoff switch is located in the junction box. The overspeed shutoff switch must be reset before you can restart the engine. To reset the switch, push the "RESET" button. The button will remain in this position unless an overspeed condition occurs.The Electronic Overspeed Switch with Cranking Termination has a 75 percent "VERIFY" button, a "RESET" button, and an "OVERSPEED" indicator lamp.The Electronic Overspeed Shutoff Switch with Cranking Termination has a sensing circuit which prevents the starter pinion from remaining engaged in the flywheel at excessive rpm. Crank Termination has an adjustable engine speed setting which signals the starter motor when the engine is firing. Cranking must be terminated. Once the speed setting is reached, a switch opens which will start the engine hour meter.Once the starting motor cranks the engine, the pinion gear can remain engaged with the flywheel as the engine speed increases. The magnetic pickup opens the circuit to the starting motor at 400 rpm which will allow the pinion gear to disengage.The circuit will remain open until the flywheel stops. which prevents energizing the starting motor circuit again while the flywheel is turning.The engine may be equipped with either an Overspeed Shutoff Switch or an Electronic Overspeed Switch with Cranking Termination. Both switches can be checked for proper operation at 75 percent of overspeed condition. Use the following procedure:
Determine full load speed (rpm) from the Engine Information Plate.
Operate the engine at or slightly above the corresponding speed (rpm) shown for the engine. Refer to table 1.
Maintain the test speed (rpm). Push and hold the "VERIFY" button. The engine should stop. If the engine does not stop at the specified test speed (rpm), contact your Caterpillar dealer.
Table 1
INDUSTRIAL ENGINE OVERSPEED TEST RPM
Full Load RPM Test RPM For Overspeed(1) Actual RPM Of Overspeed(2)
1500 1328 1770
1800 1593 2124
2000 1770 2360
2100 1859 2478