Littelfuse SE-330-05-00

The SE-330 is designed for comprehensive monitoring of neutral-grounding resistor systems, ensuring compliance with Rule 10-302 of the 2018 Canadian Electrical Code Part I. This relay continuously measures neutral current, neutral-to-ground voltage, and neutral-to-ground resistance, providing crucial oversight of the neutral-to-ground path.

An intact neutral-grounding resistor (NGR) is essential for proper ground-fault protection; any interruption can lead to a false sense of system integrity. Specifically, if the NGR is open, the ground-fault protection may become inoperative, while a shorted NGR could result in abnormally high ground-fault current levels.

Suitable for use with both low- and medium-voltage transformers and generators with varying resistance grounding, the SE-330 serves applications across various industries, including processing, manufacturing, chemical, pulp and paper, petroleum, and water treatment facilities. For high-voltage requirements, the SE-330HV is recommended, and for compliance with Australian standard AS/NZS 2081.3:2002, the SE-330AU variant is available.