Medium voltage electrical network single phase fault current reducing grounding resistor equipment

To reduce mechnical streees in circuits and apparatus carrying fault currents 

What is a Neutral Grounding Resistor 

The Neutral Grounding resistor is the connection between the system neutral and ground. It provides a path for ground fault current to return to the transformer neutral. 

Why use NGR 

To reduce burning and melting effects in faulted electrical equipment, such as switchgear, transformers, cables and rotating machines.

To reduce mechanical stresses in circuits and apparatus carrying fault currents

To reduce electrical-shock hazards to personnel caused by stray ground fault currents in the ground return path

To reduce the arc blast or flash hazard to personnel who may have accidentally caused or who happen to be in close proximity to the ground fault.

To reduce the momentary line-voltage dip occasioned by the occurrence and clearing of a ground fault.

To secure control of the transient over-voltages while at the same time avoiding the shutdown of a facility circuit on the occurrence of the first ground fault