SE-330HV Series Neutral Grounding Resistor Monitor

The SE-330 is an advanced ground-fault and neutral-grounding-resistor

monitoring relay. It measures neutral current, neutral-to-ground

voltage, and neutral-to-ground resistance. It provides

continuous monitoring of the neutral-to-ground path to verify

that the neutral-grounding resistor (NGR) is intact. This is of

utmost importance—an open NGR renders current-sensing

ground-fault protection inoperative and could result in a false

belief that the system is functioning properly. The SE-330 can be

used with low- and medium-voltage transformers and

generators with low- or high-resistance grounding used in

processing, manufacturing, chemical, pulp and paper, petroleum,

and water-treatment facilities. For high-voltage applications, use

the SE-330HV. For applications that require conformance to

Australian standard AS/NZS 2081.3:2002, see the SE-330AU.