Subpanel

Status
Not open for further replies.

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
I have a 200amp main panel. I installed a 100amp sub contigious to it. They are connected by an offset (emt) with bushings etc.

My question is have I created paralleled grounding conductors since this is a four wire sub installation?

Could this sub ever be considered to be part of the main? Or an extention of it?

Mike P.
 

charlie

Senior Member
Location
Indianapolis
Re: Subpanel

I installed a 100amp sub contigious to it.
You can not install a panelboard contiguous to it without sharing a side with the other panelboard. :D Since you are not, the grounding conductors and the grounded conductors will be separated in the downstream panelboard. Nothing would be in parallel unless you ran a separate grounding conductor. The grounding conductor and the conduit system (nipple in this case) would be in parallel. This is not a Code violation since the grounding conductor will not be a current carrying conductor except under fault conditions.

This panelboard will never be a part of the service equipment, it is downstream of the service.
 

Ed MacLaren

Senior Member
Re: Subpanel

My question is have I created paralleled grounding conductors
As stated above, parallelled equipment grounding (bonding) conductors are not a problem.
In other words, equipment grounding conductors that are in parallel with each other actually improve the fault clearing ability of the system.

It is equipment grounding paths that are in parallel with the grounded (neutral) conductor that are prohibited, because they allow normal unbalanced load current to follow equipment grounding conductor paths that may not be sized to carry it.

These objectionable currents can be prevented by bonding equipment grounding conductors to the neutral at one point only.

See also this thread.
http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=7;t=000154

Ed

[ May 13, 2003, 08:20 AM: Message edited by: Ed MacLaren ]
 
Status
Not open for further replies.
Top