NC20

Capacitor bank protection

The relay type NC20 provides protection of shunt capacitor banks and harmonic filter circuits. The capacitor banks may have the following configurations: Single Wye grounded. Single Wye ungrounded (with a resistor on the output of the neutral unbalance voltage transformer in order to develop the appropriate input current for the unbalance protection). Double Wye ungrounded. The capacitor banks may be: internally/externally fused or fuseless capacitor units. A suitable compensation method is provided to compensate the inherent unbalance neutral current Protections 37, 49 and 50/51 (RMS) are based on RMS value measurement of the three phase currents (fundamental and harmonics up to the 11th)