Description
Phase failure relay (sequence and phase failure) for protection of three-phase motors. Action against phase breaks, inverted sequence of motor phases, delay to deoperation and operation.
Applications
Protection of three-phase motors against phase breaks or wrong sequence of phases.
Protection against imbalance between phases, with factory-programmable operation delay of 1 min, 5 min, or 10 min, for protection against short-duration failures.
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 deoperation delay time regulated on the front button (2 – 14 sec.)
