CLAMP 1358168 - Caterpillar

This section contains some general information about the function of typical engine protective devices.The alarms and shutoffs are set at critical operating temperatures, pressures, fluid levels, or speeds in order to protect the engine from damage.An alarm warns the operator when an abnormal operating condition occurs. The shutoffs shut down the engine if a more critical operating condition occurs. The shutoffs help to prevent damage to the engine.If an engine protective device shuts off the engine, always determine the cause of the shutoff. Always make the necessary repairs before attempting to start the engine.Become familiar with the following information:
Types of the alarms and shutoffs
Locations of the alarm and shutoff controls
Conditions which cause each control to function
The procedure that is required before starting the engineShutoffs
The shutoffs are electrically operated or mechanically operated. The alarms for the MCS are controlled by the control panel.The particular shutoff may need to be reset before the engine will start.
Always determine the cause of the engine shutdown. Make necessary repairs before attempting to restart the engine.
Alarms
The alarms are electrically operated. The operation of the alarms are controlled by the control panel.The alarm is operated by a sensor or by a switch. When the sensor or the switch is activated a signal is sent to the control panel. An event code is created by the control panel. The control panel will send a signal in order to illuminate the lamp.Your engine may be equipped with the following sensors or switches:Coolant level - The low coolant level switch indicates when the coolant level is low.Coolant temperature - The coolant temperature sensor indicates high jacket water coolant temperature.Engine oil pressure - The engine oil pressure sensor indicates when oil pressure drops below rated system pressure, at a set engine speed.Engine overspeed - The primary speed/timing sensor checks the engine speed. 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.Testing Alarms and Shutoffs
Alarms must function properly in order to provide timely warning to the operator. Shutoffs help to prevent damage to the engine. It is impossible to determine if the engine protective devices are in good working order during normal operation. Malfunctions must be simulated in order to test the engine protective devices. Refer to this Operation and Maintenance Manual, "Engine Protective Devices - Check" for more information.Prevention of Start-up
The engine will not start if any of the conditions that cause a shutoff are present. An overcrank will also prevent starting of the engine. If any situation that causes a shutoff occurs, the following conditions must be met before the engine can