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

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. It features two programmable Form C and one programmable Form A output contacts, an analog 4-20 mA output, a pulsing output for ground-fault location, and an onboard 100-event trip recorder. The relay supports USB communication and is conformally coated for corrosion protection. It is panel- or surface-mountable, operates with ER Series sensing resistors and ELCT5 or ELCT30 current transformers, and is CSA certified, UL Listed, CE marked, and RCM compliant. Its dimensions are 213 mm high, 98 mm wide, and 132 mm deep.