Capacitor bank wiring modes



Delta wiring

This type of wiring is used for low power banks and of nominal voltages less than 12 kV.

These banks are generally designed for direct compensation on HV motor terminals. The capacitor(s) is/are generally three-phase.

Double star wiring

This type of wiring is suitable for banks of all powers and voltages (in this case, single-phase capacitors are subjected to a single voltage).

An unbalance protection device (current relay and transformer) continuously monitors the unbalance current between two neutral points and, in the event of faults in a capacitor, opens the bank control device.

H wiring

This type of wiring is designed for high power single-phase H.V. banks and V.H.V. three-phase banks. For three-phase banks, the unbalance is monitored on each phase.

This unbalance monitoring system applies to both star and delta banks.