The Speed Sensing Relay provides three user adjustable trip levels with LED relay state indicator and a speed indicator output signal.
The trip functions provided are :
The unit also incorporates the following protection features :
The protector continuously monitors the rotations speed, and updates the analog output signal. An output of 0.75mA indicates normal speed (100%) while 1mA indicates 133% of nominal speed. The calibration point can easily be user adjusted.
Three setpoint control adjustments allow setting of the desired speed limits for cracking. Under speed and over speed.
Cranking Relay : Will detect if the engine is running or stopped. This relay can be used to ensure the cranking Motor is disconnected, once the engine has started running. Set the cranking setpoint just above the cranking motor speed. A red LED illuminates when the relay is energised, indicating a trip condition.
Under speed Relay : Will detect when the normal running speed has been achieved. This can be used to enable the generator’s electrical protection. It can also be used to trigger load shedding. A red LED illuminates when an under speed condition exists.
Over speed Relay : Will detect when a stuck throttle or over shoot, and can be used to shut down the engine. A red LED indicates over speed trip.
Fail safe operation : The relay Will detect an open circuit speed sensor, and de – energise the over - speed relay.