DISC-FRICTION 9G8542 - Caterpillar

The overvoltage relay (OVR) is an option. The OVR is mounted to the subpanel within the control panel and the OVR provides system protection for line to line overvoltage. The OVR is a three-phase relay. The OVR has a setpoint for an adjustable pickup. This setpoint can be set at 100 to 125% of the nominal rating. The setpoint also has an adjustable time delay from 0.5 seconds to 20 seconds. If the system voltage exceeds the setpoint for more than the time delay setting then contacts 7 and 8 of the OVR will close. The generator set control (GSC) will record an SP1 fault and the engine is shutdown. If the generator set is equipped with an optional circuit breaker shunt trip solenoid then the generator is taken off the line. See Systems Operation, "Schematics And Wiring Diagrams".
To avoid personal injury from electrical shock, do NOT touch the high voltage terminals while adjusting the over voltage relay.
After the SP1 fault is corrected, the generator set control (GSC) is reset by turning the engine control switch (ECS) to the OFF/RESET position. The generator output circuit breaker must also be reset if the generator is equipped with a shunt trip. The setpoints are adjustable in the field. The setpoint for the pickup is set at the factory to the maximum value. The setpoint is 125% of nominal rating for the relay.