The Global Need
One of the recurring phenomena in the electrical distribution network is the disconnecting of the phase to the customer, or phase failure. When the client is connected at the end of a high voltage line that feeds many customers, phase disconnection due to the rupture of a bridge or wires is not noticeable in the utility company monitoring and protection systems installed in the substation as long as the torn wire does not touch another phase or ground. Phase disconnection at the end of the line does not usually cause a significant change in the current, so the utility monitoring systems are unable to detect such a situation. For phase disconnection there may be a number of other reasons: fuse burning, malfunction in the electromechanical components, failure to contact one of the terminals of the disconnector,
Quickly troubleshooting a phase loss and determining the root cause is often difficult.
Voltages and currents in a three-phase system do not typically just drop to zero when a phase is lost. Often measurements yield confusing values that require a great deal of complex analysis to correctly interpret. Meanwhile, damage and downtime of the equipment continues to rise.
A three-phase client receiving only two phases, can cause significant damage to the equipment around. Therefore, the protection of the phase loss is a mandatory defense.
Phasor unique solution to Phase Failure
Unlike other phase-loss protection relays or other under-voltage / overvoltage protection relays that immediately disconnects the apparatus, Phasor PCM module maintains the
power supply continuity in cases of a single/double phase failure regardless of the reason, by automatically feeding 1-Phase consumers from one of the remaining live phases. As soon as the power supply is restored and back to normal, the system automatically restores to normal state. This model has the Neutral Failure Protection mechanism integrated.