Neutral Earthing Resistors
Neutral Earthing Resistors are a key component in the earth fault protection of medium voltage electricity generation and distribution systems.
Cressall NERs limit the current that would flow through the neutral point of a transformer or generator in the event of an earth fault.
Features of all Cressall grounding resistors include:
- Current ratings up to 8,000 Amps
- Full compliance with ANSI-IEEE 32, Terminology and Test Procedure for Neutral Grounding Devices
- Stainless steel resistors and enclosures as standard, IP23 to IP56. (Cable boxes up to IP65)
- Type-tested standard designs (certificates available)
- Supply of resistor banks only for incorporation into customer’s own enclosures
- Shock-tested marine designs
- Provision for CTs, heaters, special cabling, etc.
- Interlocked off-load by-pass isolators
- Single or multiple vacuum contactors
- High resistance grounding resistors (for use where regulations permit, e.g. some offshore installations)