Littelfuse, Inc. SE-330 Series – Neutral-Grounding-Resistor Monitor SE-330-03-00

The SE-330 is a neutral-grounding-resistor monitoring relay that continuously measures neutral current, voltage, and resistance to detect open or shorted grounding resistors and ground faults as small as 100 mA. It features Discrete Fourier Transform filtering to prevent false trips from harmonic noise, programmable Form A and Form C output contacts, an analog 4-20 mA output, and an on-board event recorder. The unit includes a Mini USB port for local communication and supports Ethernet (Dual RJ45) for network connectivity. It is conformally coated for moisture protection, operates with a universal current transformer, and is CSA certified, UL Listed, CE marked, and RCM compliant. The device is designed for panel or surface mounting and measures 213 mm in height, 98 mm in width, and 132 mm in depth.