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

The SE-325D is a neutral-grounding-resistor monitor designed for resistance-grounded systems up to 25 kV, with a control power input of 120 Vac/Vdc. It monitors neutral-to-ground current and voltage to detect NGR failures, ground faults, or loose connections, offering adjustable ground-fault trip levels from 0.5 to 4.0 A and trip delays from 0.1 to 2.0 seconds. It features a Form A output contact with selectable fail-safe or non-fail-safe operating modes, conformal coating, and a standard reset button. The device measures 150 mm in height, 109 mm in width, and 100 mm in depth. It is CSA certified, UL Listed (E340889), and C-Tick compliant.