Littelfuse, Inc. SE-330 Series – Neutral-Grounding-Resistor Monitor SE-330-24-00

The SE-330 is a ground-fault and neutral-grounding-resistor monitoring relay that measures neutral current, voltage, and resistance to detect open or shorted neutral-grounding resistors. It supports systems up to 35 kV and detects ground-fault currents as low as 100 mA using DFT filtering to prevent false trips from harmonic noise. The relay features two programmable Form C and one programmable Form A output contacts, an analog 4-20 mA output, and a pulsing output for ground-fault location. It includes a mini USB port for local communication, an onboard microSD card for data logging, and a 100-event trip recorder. The unit is conformally coated, panel or surface mountable, and operates with a 48 Vdc power supply. It is CSA certified, UL Listed, CE compliant, and RCM marked.