Littelfuse, Inc. SE-330 Series – Neutral-Grounding-Resistor Monitor SE-330-21-00

The SE-330 is a neutral-grounding-resistor monitoring relay that continuously verifies the integrity of the neutral-grounding resistor by measuring neutral current, neutral-to-ground voltage, and resistance. It detects open or shorted resistors and ground faults as small as 100 mA using Discrete Fourier Transform filtering to prevent false trips from harmonic noise. The unit features two programmable Form C and one programmable Form A output contacts, an analog 4-20 mA output, and supports USB, DeviceNet, and IEC 61850 communication options. It has a panel or surface mount style, dimensions of 213 mm H × 98 mm W × 132 mm D, and is conformally coated. Approved by CSA, UL, CE, and RCM. The SE-330-21-00 variant includes a 48 Vdc power supply and DeviceNet communication.