Use of NGR

Search Neutral Grounding resistor or NGR in this forum, there are lots of threads on the subject.

NGR is the sound I make when I am really frustrated about something (but with a few more Rs, like NGRRRRRRR!)

Pick the balls others dropped!!!!........

Draw out a 3-phase elementary drawing of the system. If there is a NGR in the generator neutral, any fault to ground that is fed by the generator would have to flow back through the resistor. The value and thermal capacity of the resistor are sized to handle the limited current (for example, 400 amps for 10 seconds, plenty of time for protective relays to operate).

I fear your understanding is a weebit incorrect. The purpose of NGR is to reduce the fault current during an earth fault (it could be an L-G fault or an L-L-G fault too). It will work well both in case of transformers as well as in the case of generators. More so in generators, as the single line to earth fault current in generators can be more than the three phase fault current and thus, it obviates the need for an NGR to limit the single line to ground fault current fed by a generator. More concerns would also be towards core damages in rotating electrical machines like generators during an internal line to ground fault.

What u told is correct. But how it will limit the fault current. Bcoz resistor is placed in the neutral and current flows from the generator. You mean since the neutral is the nearest free path for current flow, it will try to flow thro that path. So if we place the resistor in the shortest path, the fault current will find difficult to flow.

Am i right?

-Vijay