ARTICLE 250.36 ?

[electricaldoc]

High-Impedance Grounded Neutral Systems?
Other than having a resistor between grounded conductor and grounding conductor. Can any one explain exactly what this system is, and what reasons you would use it? Any examples of some that I could relate to? I have yet to encounter any of these systems, and there fore unfamiliar with them.

Thanks

 

[Ed MacLaren]

Re: ARTICLE 250.36 ?

The High-Impedance Grounded System provides the advantages of an ungrounded system while preventing most of the problems.

The main advantage is that the first ground fault will not open an OCPD.
Providing that first fault is located and repaired before a second ground fault occurs, there is no interruption of power to critical processes.
Time is provided for orderly shutdowns.

More info here

And here

The sketch illustrates a typical installation.

Ed

[ February 02, 2005, 09:28 AM: Message edited by: Ed MacLaren ]

 

[kiloamp7]

Re: ARTICLE 250.36 ?

I realize you are talking about High Impedance Neutral Grounding.
Thought I'd mention there is also a concept of Low Impedance Neutral Grounding.
It is usually used in medium voltage systems, mainly to limit fault currents.