818304 Mercruiser COVER

Manual Shutoff Lever
Emergency Stop button (if equipped)In the event of an overspeed, shut down the engine with the Manual Shutoff Lever (for fuel shutoff ONLY) or push the Emergency Stop button (if equipped), and both air and fuel will be shut off.
Typical ExampleThe air shutoff requires manually resetting of the air shutoff levers on the bank air inlets (on the 3516, BOTH banks) of the engine before starting the engine. The RESET button on the speed switch must be manually pushed before the engine can be restarted.The operation of all electrical shutoff controls is similar. A critical operating condition actuates a switch to stop the engine. The shutoff control requires resetting before the engine can start (on an overspeed shutdown only).The shutdown controls should be tested every 92 Day FRA Inspection or 1000 service hours by authorized personnel.Always determine the cause of the shutdown and have the necessary repairs made before restarting the engine. Never use the Emergency Shutdown controls or Emergency Stop button (if equipped) for a normal stopping procedure. Refer to "Engine Stopping" section in this publication for proper normal shutdown procedure.Alarm Systems
Typical Installation Refer to Locomotive OEM for alarm and annunciator installation. Alarm systems and features may or may not be connected to audible or visual indicators as described in this publication.
Engine Mounted ContactorsAlarm switches consist of a sensor and contactor. The sensor such as magnetic pickup for detecting speed, or pressure or temperature sensors are wired to a contactor which activates an alarm circuit in the Annunciator Panel.Alarm switches and sensors are set at a less critical temperature, pressure or level limit than the engine shutdown controls.The purpose of the alarm switch is to warn the operator that an unsafe operating condition is beginning to occur.The Annunciator Panel has lights and an audible device to warn the operator of a malfunction or abnormal engine operating condition. Each alarm contactor and switch is electrically connected to an indicator light or audible indicator. The alarm will continue until the condition is corrected.When an alarm is activated, corrective measures must be taken before the situation becomes an emergency to avoid possible damage to the engine.If corrective measures are not taken within a reasonable time, engine damage could result, or if equipped, a corresponding shutdown device will stop the engine.The alarm will continue until the condition is corrected or the alarm is reset by the operator. The alarm circuits merely warn the operator, they do not shut the engine down to protect it from damage.Shutdown and Alarm System Testing
During testing, abnormal operating conditions must be simulated. Perform the tests correctly to prevent possible damage to the engine.
All alarms on the engine should be checked at least every 92 Day FRA (Federal Railway Administration) Inspection or four times per year for proper operation by authorized Caterpillar dealer personnel.Abnormal operating conditions must be simulated which could cause engine damage if the tests are performed incorrectly. Refer to the Service Manual for the testing procedure.Test Governor Diagnostic Lights
There are eight light emitting diodes (LED) located on the electronic governor control box that indicate engine status and provide diagnostic information from the control.By turning the power switch ON, all of the indicator LEDs on the electronic governor control box activate automatically for the first five seconds and can be checked for proper operation. Test the indicator LEDs periodically if locomotive engine is not shut down or every 92 Day FRA (Federal Railway Administration) inspection interval.Oil Pressure Alarm
The oil pressure switch (A) senses oil pressure at the bearing oil gallery. The alarm is set to trip at 200 20 kPa (29 3 psi) at LOW rpm (less than 1000 rpm) (1) and 360 20 kPa (52 3 psi) at HIGH rpm (greater than 1000 rpm) (2). No resetting procedure is required. Switches may reclose at 48 to 62 kPa (7 to 9 psi) above actual trip point.High Water Temperature Alarm
This alarm is a high coolant temperature alarm (1). The shutoff sensor (2) is located in the water lines from the water pump housing to the aftercooler and senses the cooling system water temperature. Excessive water temperature closes the switch. Maximum coolant temperature to trip alarm is 104°C (219°F). The switch opens as the coolant cools. No resetting procedure is required.
The sensing element must be submerged in the coolant to operate. Be sure to have adequate water supply in jacket water system or engine damage could result.
Low Oil Level Annunciator
This annunciator senses low oil level in the engine oil pan. The engine oil must be filled to the proper sump level to reset the annunciator. Inspect dipstick for proper sump level. Refer to Maintenance Schedule-Daily, Engine Crankcase, Check Oil Level topic for more information.High Oil Temperature Alarm (If Equipped)
The high oil temperature alarm is set at 110 2°C (230 4°F). No resetting is required.