isolated ground panel

[Jeff Rae]

installing a sub panel needing an isolated ground how far back do you have to terminate the insulated grouding conductor and is any additional grounding required at the main. in the same mech. room is an oil filled transformer where the xo bushing has the grounded and grounding conductors bonded.do i haveto go to the transformer???

[ August 24, 2005, 07:36 AM: Message edited by: Jeff Rae ]

 

[petersonra]

Re: isolated ground panel

by rights an IG is connected to the ground bar back at the service point.

whether you choose to actually run it back that far is another thing, since it could be quite a distance.

IG's are overrated IMO. I do not believe they are especially useful indoing any of the things touted for them.

 

[infinity]

Re: isolated ground panel

I'm with Bob, IG's are overrated and unnecessary. Running a EGC with the circuit conductors is all that you'll need. As he said a true IG should go back to the service or the transformer Xo of a separately derived system.

 

[hardworkingstiff]

Re: isolated ground panel

You can put me in the over rated camp also. A well grounded receptacle is every bit as good as an IG.

I remember 7-11 in the 70's having IG's installed for their new cash registers. They did it incorrectly (drove a ground rod at the counter and connected their ground there). After years of problems, they went in and undid everything.

(edited for grammer (there/their))

[ August 23, 2005, 08:34 PM: Message edited by: hardworkingstiff ]

 

[steve66]

Re: isolated ground panel

I agree 100%. The ground is a safety device, right? It might also add some protection from Radio-Frequency-Interference. But what device actually uses the ground connection for a circuit conductor, or as part of the electronic circuit? Am I correct that almost none would use the ground under normal circumstances? Then why would any current on the ground cause problems?

Steve