| Jeff Miller 2007-04-11, 9:25 pm |
| I know that your setup sounds correct, neutral and ground should not be
bonded in the sub-panel. But I forget exactly why. Something like, if the
ground and neutral get broken between the boxes (or maybe it's just if the
ground gets broken) the neutral,. being bonded to ground and to the box, may
lift the box to a high potential.
I'm curious as to the real explanation though. Hope someone responds.
-Jeff
"Randell Tarin" <thetarins@earthlink.net> wrote in message
news:pK4Eh.6183$tD2.4232@newsread1.news.pas.earthlink.net...
> SETUP: 200 AMP Main Panel connected to a 100 AMP sub-panel via metallic
> nipple. A 75 AMP breaker in the main panel feeds the sub via #4
> conductor. The Neutral is isolated from the ground in the sub. Bare
> grounding conductors are attached to the subpanel through an equipment
> bar attached to the metallic case of the sub.
>
> Can someone explain to me why the NEUTRAL and GROUND must be isolated in
> the sub-panel since they are already bonded in the Main panel. Since
> the ground in the SUB is derived from the link of the two metallic
> enclosures, isn't the NEUTRAL in the SUB already bonded to the ground???
>
> What happens if the NEUTRAL AND GROUND are also bonded in the subpanel?
>
|