Grounding resistor monitoring system SE-325 series

transformerground fault

The SE-325 series is a neutral-grounding-resistor monitor used on resistance-grounded systems up to 25 kV to monitor the integrity of the neutral-to-ground path and to detect ground faults. It measures current and voltage in a transformer or generator neutral-to-ground connection and continuity of the neutral-grounding resistor (NGR). The SE-325 monitor coordinates these three measurements to detect a loose connection, corrosion, ground fault, or NGR failure, and provides one alarm or trip output contact. Features Continuous NGR monitoring Ground-fault detection Adjustable pickup (0.5–4 A) Adjustable time delay (0.1–2 s) Output contacts Selectable contact operating mode Benefits Detects resistor failure within seconds, reduces transient-overvoltage risk, removes risk of ground-fault detection failure Main or backup protection to detect a ground fault anywhere on the monitored system Select greatest sensitivity without false operation Adjustable trip delay allows system coordination Form A output contact Selectable fail-safe or non-fail-safe operating modes allow connection to shunt or undervoltage breaker coil or alarm system