Voltage control relay RSR series

under-voltageACfor electric motors

The RSR-72 type relay for re-start and reacceleration is deigned to perform the automatic motor restarting, after control and protection device opening, as a consequence of a momentary line voltage interruption or drop-out. The RSR-72 relays allow, after the stop of the motors, the automatic re-start with a correct sequence depending of the working process.The RSR-72 relays are housed in a case for flush mounting or panel mounting or on DIN rail 35 mm on extractible undecal socket type. On front panel there are potentiometers and micro-switches for settings and one LED to indicate the functional status. GENERAL CHARACTERISTICS The RSR-72 relay is used in association with an holding position contact. Otherwise from the RSR-72, the RSR-72A maintains the contact closed after the restarting the motor/contactor. On the relay is possible to set a memory time from 0.2 to 60 seconds and a delay time from 0.2 to 1000 seconds. Anytime a voltage lack (or with a value less of 65% of the rated voltage) and subsequently the voltage restores (at least the 90% of the rated voltage) within the memory time set the re-start motor output will be activated after the delay set. If the voltage restores after the memory time, the automatic re-start will not happen, while the voltage restores in a time less than 0.2 seconds (the minimum memory time), the motor will reaccelerate. If the reacceleration function is activated and the voltage go back in a time less than 0.2 seconds (maximum time for reacceleration) the motor will reaccelerate immediately, if the reacceleration function is not activated after the delay time the motor will restart automatically.