Neutral Grounding Reactors

Neutral Grounding Reactors (NGRs) are used to control single line to ground faults only. NGR are particularly used at transmission voltage levels, when autotransformers with a delta tertiary are employed. Neutral Grounding Reactors (NGRs), normally installed between the transformer or generator neutral and ground, are effective in controlling single line to ground faults since, in general, the system short circuit impedance is largely reactive. NGRs reduce short circuit stresses on station transformers the most prevalent type of fault in an electrical system.