GEAR 2W8813 - Caterpillar

Engine speed is determined from a signal that is provided to the Electronic Control Module (ECM) by the engine speed/timing sensors. The ECM monitors the speed signal in order to ensure that the engine speed does not exceed a preset value. If the speed signal indicates that the engine speed has exceeded this value, an engine overspeed condition has occurred. When an overspeed condition occurs, the engine monitoring system records the engine overspeed condition in ECM memory. The monitoring system then initiates protective measures.Engine Overspeed Protection
Serious damage to the engine and to any engine driven component may result during an engine overspeed. Engine overspeed protection is a safety feature that will take the necessary measures in order to initiate an engine shutdown in the event of an engine overspeed condition.This generator set application may be equipped with an Electronic Modular Control Panel II (EMCP II) that is used to provide engine control. If this control panel is installed, the EMCP II will perform the engine monitoring and protection functions for the engine. The control panel uses separate engine speed sensors that are located in the flywheel housing.The following engine protection is available for engine overspeed:SHUTDOWN - The only engine monitoring mode that is available for this application is the "SHUTDOWN" mode. An engine overspeed condition will initiate an engine shutdown when the EMCP II is programmed to "SHUTDOWN". The generator control will instruct the ECM to stop fuel injection to the cylinders during an engine overspeed condition. This generator set may be equipped with an emergency air shutoff. If the air shutoff is available, the generator control will also activate the air shutoff solenoid. The air shutoff solenoid must be reset by cycling power to the EMCP II before the engine is restarted.The above mode of operation is available at various engine speed setpoints.For more detailed information about the operation of the control panel, refer to Operation and Maintenance Manual, SEBU7050, "SR4B Generators and Control Panels".