Littelfuse offers a variety of resistance grounding/NGR monitoring products that work by limiting the fault current so it does not cause unwanted fault damage, but still allows the protective relays to work as designed. These high-quality products prevent many of the problems that are associated with ungrounded and solidly-grounded electrical distribution systems. They also monitor the neutral-to-ground connection. These units can limit point-of-fault damage, eliminate transient overvoltages, reduce arc-flash hazards, and provide adequate tripping levels for selective current-based, ground-fault detection..

 

Model	Image	Description
NGR Series		High-resistance grounding prevents many of the problems that are associated with ungrounded and solidly grounded electrical distribution and utilization systems. High-resistance grounding can limit point-of-fault damage, eliminate transient overvoltages, reduce the arc-flash hazards, limit voltage exposure to personnel, and provide adequate tripping levels for selective current-based ground-fault detection and coordination.
SE-325 SERIES		The SE-325 Neutral-Grounding-Resistor Monitor is used on resistance-grounded systems up to 25 kV to monitor the integrity of the neutral-to-ground path and to detect ground faults. It measures current and voltage in a transformer or generator neutral-to-ground connection and continuity of the neutral-grounding resistor (NGR).
SE-330, SE-330HV SERIES		The SE-330 is an advanced ground-fault and neutral-grounding-resistor monitoring relay that is compliant with Rule10-302 of the 2018 Canadian Electrical Code Part I (CE Code). It measures neutral current, neutral-to-ground voltage, and neutral-to-ground resistance.