CDU Series DC current monitor relays from the ATC Diversified Electronics division of Marsh Bellofram is used to detect UNDER CURRENT conditions. The internal relay is energized (Pick-up) when the monitored current is above the preset trip point. The relay de-energizes (Drop-out) when the current falls below the trip point for longer than the adjustable delay. The delay is incorporated to prevent nuisance tripping caused by momentary line dips. The relay re-energizes when the current rises 5% above the Drop-out trip point for longer than 0.2 seconds. The relay has the automatic reset feature.
