Coal

Neutral Grounding Resistors

Issue 1 and Volume 102.

Neutral Grounding Resistors

An entire series of Neutral Grounding Resistors for industrial electrical distribution systems is now available from Avtron Manufacturing Inc. Avtron Neutral Grounding Resistors are installed between the neutral of a generator (or transformer) and earth ground so as to limit the maximum fault current to a safe level (typically 25 to 400 amps). These lower levels protect generators, transformers, motors, wiring and associated equipment while allowing sufficient current flow to operate fault-clearing relays. A typical four-wire system that is solidly grounded to an earth ground without a neutral grounding resistor can experience high ground fault currents of 10,000 to 20,000 amps. In addition, transient overvoltages (up to six times the normal voltage) can occur during arcing-type ground faults. Avtron Neutral Grounding Resistors are designed and tested in strict accordance with IEEE Standard 32-1972, which specifies maximum allowable temperature ratings for neutral grounding devices for various duty cycles. Avtron`s quality policy is certified to meet ISO 9001 standards. Avtron Neutral Grounding Resistors feature resistor elements, terminals, support rods and exterior fasteners made from stainless steel for added durability. Models can be supplied with open flames for placement inside switchgear or similar enclosures, or they can be fully assembled within Avtron`s indoor/outdoor safety enclosures, constructed from corrosion-resistant aluminized steel.

Avtron Manufacturing Inc.

Circle 160