Description

Relay of sequence and lack of phase for protection of three-phase motors. Action against phase breaks or inverted sequence of motor phases and delay to deoperation.

Applications

 Protection of three-phase motors against phase breaks or wrong sequence of phases.

Protection against lack of phases, in case of absence of regenerated tensions.

Protection against phase imbalance.

Control of voltage value in generator groups.

Operation

Feed the relay (green LED lights up – A.1)

Contact “S1” arms when the rotation of the phases is in sequence and the voltage value of all three exceeds the minimum limit regulated on the front panel scale.

Contact “S1” disarms when the individual value of the measurement of one or more phases drops below the minimum limit regulated on the sensitivity button, and after the delay time to deoperation regulated on the front button (2 – 14 sec.)