MOTOR MULTI-PROTECTION RELAY S91

S91 is a protection device for electric motors that allows the detection of wrong phase sequence or lack of a phase, of the excess current consumption, no-load operation with the power factor measurement. Equipped with rotary programming switches and a display of alarm signaling, the device is characterized by an input for PTC to protect the motor from overtemperature and enable input for starting the engine. S91 operates in 3 operation modes: single-phase or threephase, maximum current range 5 or 16 A, operation with or without PTC. Main applications are protection of single-phase or three-phase pumps for possible rotor stop and for overtemperature as well as device failure detection of mechanical transmission (e.g. belts or chains) with protection against transmission system lockdown.