Retrofitting with the ZERO-hertz will allow you to greatly extend the life of your existing DC switchgear, while providing Superior Overcurrent Protection and Coordination Flexibility which, up until now, has been unavailable even on new switchgear. Standard protective functions include Long-Time, Short-Time, Instantaneous, High-Speed, Ground-Fault and Reverse-Current.

In addition, the ZERO-Hertz is AC Testable. Current pick-up and trip timing tests now can be accurately performed on a completely retrofitted breaker using a standard 60Hz AC high current test set. The displayed current, pick-up currents and the trip times are the same for the equivalent DC or AC RMS currents. No "fudge factors" are required.

The ZERO-Hertz is typically supplied as a complete retrofit kit for both one and two pole, open air power circuit breakers with frame ratings up to 12,000 amps. Several kits are currently available for the DC versions of the familiar GE AK and AL, the Westinghouse DB and the ITE K-Line series of circuit breakers. Complete kits are also available for 750VDC and higher voltage range breakers such as the GE MC5 and MC6, the Westinghouse DR-150 and DMD, and the ITE FB series of breakers.