passing wire through a panel

18 years ago

I'm installing a generator interlock switch to my main panel and have a question on running the wire in from the inlet outlet for the generator. I have a in the wall main panel with a sub panel in the adjacent stud cavity. I'll be mounting the inlet box next to the sub panel on the wall. It would be easiest to run the wire from the inlet box into the sub panel, then trough the conduit that connects it to the main panel and hook it up to the backfed breaker in the main panel. Can I legally do this, and if I'm using romex type cable (10/3), can I leave the wires in the insulation as it runs through the sub panel,then strip the wires where they enter the main panel. My reason for doing it his way is that I would not have to open up the dry wall to do it this way or drill any studs. My space around the panels for mounting the inlet box is very limited.

Lastly, I read on one forum that you need a special backfeed breaker for the interlock switch but when I questioned an electrician while I at the electric supply shop picking up parts, he said he just uses normal breakers for hoooking up interlock switches

Thanks for your answers. Kevin

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Comments (6)

Ron Natalie
18 years ago
As long as you don't violate the conduit fill and other rules, there's nothing that precludes you from doing this.

The requirement for a backfeed breaker is that it have some mechanism to prevent the inadvertant removal of an energised breaker (408.16(f)). Sometimes it's an add on to a standard breaker (typically a screw), sometimes it's a different style breaker. You need to check the particular manufacturer's requirements.
dezwit
18 years ago
You just need a standard breaker that you will backfeed with the wire from the generator. It will install directly below your main so the interlock kit prevents both breakers from being turned on at the same time.
There will be some kind of bracket or screw kit to lock it in place in many cases but not all.
The kit will be a separate item that you will have to ask for.
What kind of panel are we dealing with here?
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keast
Original Author
18 years ago
It's a GE load center. The switch I plan on using is one made by Interlock Technologies. I can only find one type that GE makes and it is not for my type of panel. The interlock tech switch is pricy by seems to be the only alternative. I could easily make one myself but I suppose the local authorities would frown upon that.

Can I run that wire through the sub panel and leave the isulation on it until it enters the main load center?
Ron Natalie
18 years ago
By insulation I assume you mean the cable sheath. Yes you can.

It is an ABSOLUTE requirement by the NEC to have an additional fastening means for the backfed breaker regardless of who makes it. The only thing that changes with the manufacture is the means of achieving that additional lock.
keast
Original Author
18 years ago
Ron, thanks for the imput. Yes, by insulation, I mean cable sheath. Out of curiosity, do you know why other than code, the backfed breaker needs an additional fastening means?
greg_h
18 years ago
I think Ron answered that in his first post.
The requirement for a backfeed breaker is that it have some mechanism to prevent the inadvertant removal of an energised breaker (408.16(f)).