Reverse Power Protection Relays

Reverse power protection relays protect parallel operated generators against reverse current flows, tripping upon fault condition. The output relay trips when the monitored reverse current exceeds the user adjustable limit and the reverse power LED illuminates indicating a fault condition. The trip point is adjustable from 2% to 20% of the nominal current through the front control knob. The relay also has a built-in time delay, adjustable from 0.2 to 20 seconds, used to avoid nuisance tripping. The output relay is set to energise in reverse power conditions but can be supplied to de-energise if required. The relays are self powered, requiring no auxiliary power supply and LEDs indicate forward and reverse power conditions.

Key Terms: B871/1 - B871/3 - Reverse Power - Protection Relay