Does anyone know of an online graphic showing an isolated ground conductor terminating in a sub panelboard? I can't find a drawing I had in in my EC&M, IAEI, CEE or one of my other magazines. I believe it's NEC compliant to terminate at the nearest panelboard if you choose, instead of running it all the way back to the service equipment.

Frank,
The code permits you to pass the isolated equipment grounding conductor through panels without landing it, it does not require you to do so. As long as it is connected to a proper fault clearing path, the point of connection becomes a design issue, not a code issue.
Don(resqcapt19)

This months or last months EC&M (I'll check tomorrow). Last page discusses isolated grounds. However, one of the drawings didn't seem right to me. (I think the IG terminal jumped to the metal box, which, once the receptacle is mounted, seems to defeat the purpose of IG.) I'll check tomorrow, and maybe someone can teach me something.

Would anyone like me to draw up a few example IG termination schemes?

I can do drawings from "Most Convenient" to "Binford 6100 IG System".

Scott SET

Scott,

Would you draw an example of an isolated ground conductor terminating in a sub panelboard.

Frank,

October,2001 issue EC&M. Last page.

Don,

If you connect the IG terminal to a 1900 box that is installed with EMT, then mount the receptacle to that box, what have you gained?

[This message has been edited by Redsy (edited 11-15-2001).]

Scott,
Really? The Binford 6100 IG System sounds like something that Tim the Toolman would have done on the TV show Home Improvement.
Redsy,
All you gain is spending some $$ for nothing, and an orange recp that sticks out like a sore thumb. Blockbuster Videos used to do them like that so that their technically deprived Managers would know where to plug in the cash registers and workstations.

Redsy,

Thank you for the information. I'm trying to determine what is NEC minimum. As Don points out in his reply: "beyond that it is a design issue". It's my understanding you can terminate an isolated ground conductor at the nearest sub panel or of course run it all the way back to the service equipment.

[This message has been edited by Frank Cinker (edited 11-15-2001).]

Redsy,
Yes, if you connect it to the metal raceway or box, you have lost the intended isolation, but it would not be a code violation. The amount of isolation required is a design issue, not a safety or code issue. You are permitted to connect it anywhere on the grounding system that will provide the required fault clearing path.
Don(resqcapt19)

Does anyone know the internet address for EC&M Magazine?

Frank www.electricalzone.com

Thank you.

Hi all,

I'll post some simple to read / understand images of IG methods.

As Don pointed out, it is a designing issue. If you simply bond the IG Receptacle to any convenient EGC or Grounded Enclosure / Box, that will satisfy the NEC Grounding Requirements [which could be as simple as a green jumper wire from the Receptacle's Ground Terminal to the 4s box it's mounted in!].

As to an effective IG, Isolation back to the subpanel is not too bad [sometimes ]. Running a dedicated IG conductor from the Grounding Electrode / Grounded Conductor Bond for the system feeding the IG circuit, to the panel[s] or subpanel[s] is usually the intended design method.
This can be sized to the highest OCPD for an IG branch circuit [normally #12 cu], but most of the time a #8 or #6 is specified.

Scott [electure],

Ya, the Binford 6100 IG system was a reference to Tool Time

It would be the ultimate IG system of such mammoth complexity and overkill, Tim Taylor would totally be obcessed with it!

I won't be going to that extreme!

I'll just post relavent examples.

Scott SET