Neutral-Grounding-Resistor Monitoring Littelfuse* Expertise Applied | Answers Delivered Neutral-Grounding-Resistor Monitor Description The SE-325 Neutral-Grounding-Resistor Monitor is 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 coordinates these three measurements to detect a loose connection, corrosion, ground fault, or NGR failure, and provides one alarm or trip output contact. Features & Benefits FEATURES BENEFITS Detects resistor failure within seconds, reduces transient-overvoltage risk, removes risk of ground-fault-detection failure Simplified Circuit Diagram Ground-fault Main or backup protection to detect a ground Detection fault anywhere on the monitored system Adjustable pickup Select greatest sensitivity without AM^sb^ time delay Adjustable trip delay allows system coordination Ordering Information ORDERING NUMBER Consult manual online for additional ordering options. Specifications IEEE Device Numbers Input Voltage Dimensions GF Trip Level Settings GF Trip Time Settings RF Trip-Level Settings Contact Operating Mode Reset Button Output Contacts Approvals Conformally coated Warranty Mounting Ground Fault (50G/N, 51G/N), Overvoltage (59N), Lockout Relay (86), Checking Relay (3) See ordering information H 150 mm (5.9"); W 109 mm (4.3"); D 100 mm (4.0") 0.5-4.0 A 0.1-2.0 s 20-400 Vac (<5 kV systems) 100-2,000 Vac (>5 kV systems) Selectable fail-safe or non-fail-safe Standard feature Form A CSA certified, UL Listed (E340889), C-Tick (Australian) Standard feature 5 years Surface © 2016 Littelfuse Protection Relays & Controls Littelfuse.com/se-325