CROMPTON 
253-PH3U 
PROTECTOR TRIP RELAY 

THE 250 SERIES SPEED SENSING RELAY MONITORS ROTATING EQUIPMENT AND PROVIDES THREE OUTPUT CONTACTS WHICH CAN BE USED TO INITIATE ALARM OR SHUTDOWN SIGNALS. THE RELAY ALSO PROVIDES A TACHOMETER OUTPUT FOR SPEED INDICATION. SPEED SENSING RELAYS ARE IDEALLY SUITED FOR ENGINE AND GAS TURBINE MONITORING AND THE PROTECTION OF GENERATOR SETS. 

THE SPEED SENSING PROTECTOR MONITORS THE SPEED OF ROTATION USING A LOW COST MAGNETIC PICKUP. SPEED SENSORS ARE OFTEN USED IN GENERATOR SET ENGINES, GAS TURBINES, MOTORS, GEAR BOXES OR ANY ROTATING MACHINES. THE RELAY WILL DETECT UNDER-SPEED, OVER-SPEED AND STOPPED CONDITIONS AND THE SET POINT RELAYS CAN BE USED TO RAISE AN ALARM OR SHUT DOWN THE EQUIPMENT. THE RELAY PROVIDES THREE USER ADJUSTABLE TRIP LEVELS WITH LED RELAY STATE INDICATION AND A SPEED INDICATOR OUTPUT SIGNAL.