Littelfuse, Inc. SE-330 Series – Neutral-Grounding-Resistor Monitor SE-330-00-01

The SE-330 is a neutral-grounding-resistor monitoring relay that detects open or shorted neutral-grounding resistors and ground-fault currents as low as 100 mA using Discrete Fourier Transform filtering to prevent false trips from harmonic noise. It monitors neutral current, neutral-to-ground voltage, and resistance, and supports pulsing ground-fault location. The relay features two programmable Form C and one programmable Form A output contacts, an analog 4-20 mA output, a mini USB port for local communication, and an optional microSD card for data logging. It is conformally coated for moisture protection, has a panel or surface mount style, and measures 213 mm high, 98 mm wide, and 132 mm deep. The device is CSA certified, UL Listed (E340889), CE marked, and RCM compliant. For SE-330-00-01, the ordering code indicates a USB-only communication option and a 120/240 Vac/Vdc power supply.