Littelfuse, Inc. SE-330 Series – Neutral-Grounding-Resistor Monitor SE-330-04-01

The SE-330 is a neutral-grounding-resistor monitoring relay designed to detect open or shorted neutral-grounding resistors and ground faults as low as 100 mA using Discrete Fourier Transform filtering to prevent false trips from harmonic noise. It supports system voltages up to 35 kV and features two programmable Form C and one programmable Form A output contacts, an analog 4-20 mA output, and an on-board microSD card for data logging. The unit includes a Mini USB port for local communication and supports Ethernet (dual RJ45), DeviceNet, and IEC 61850 for network connectivity. It is conformally coated, panel or surface mountable, and certified to CSA, UL, CE, and RCM standards. The SE-330-04-01 variant includes a 120/240 Vac/Vdc power supply and dual RJ45 Ethernet interface. Dimensions are 213 mm H × 98 mm W × 132 mm D.