Littelfuse, Inc. SE-325 Series – Neutral-Grounding-Resistor Monitor SE-325NT

The SE-325 series is a neutral-grounding-resistor monitor for resistance-grounded systems up to 25 kV, designed to detect NGR failures, loose connections, and ground faults by measuring current and voltage in the neutral-to-ground path. It provides a single Form A output contact with selectable fail-safe or non-fail-safe operating modes, adjustable ground-fault trip levels from 0.5 to 4.0 A, and adjustable trip delays from 0.1 to 2.0 seconds. The device is conformally coated, includes a standard reset button, and is CSA certified, UL Listed (E340889), and C-Tick compliant. It is mounted on a surface and has dimensions of 150 mm high, 109 mm wide, and 100 mm deep. The control power input voltage varies by variant, as specified in ordering information.