Moving electrical panel. Do I need to rewire all circuits?

Question

We are planning a large remodel in our home. As part of creating a basement apartment we have to relocate the electrical panel so that it's accessible to us as well as the tenants. We will do that by moving the panel a few feet and flipping it to face the outside of the house so it can be accessed from the exterior.

Here's the question: Our GC tells us that as part of moving the panel we need to run new wiring for all existing circuits in the house. The reason for this is that we are effectively establishing new service and the existing wiring can't be extended and/or reused. Is that correct? Is there a way we can meet code and not have to run new wiring for every circuit in the house?

Update: Reading the answers to Relocating Main Panel, seems like it would be possible to install junction boxes and use them to splice the wiring for the existing branch circuits. Is this correct? I'm located in Seattle if it makes a difference.

Answer 1

Yes. I fit steel junction boxes in places the old wires can reach. Then run EMT conduit between the panel and those boxes. No more than 3 circuits (MWBC counts as 1) in each conduit and use 3/4" conduit, for easy pulling and future expansion. NEC limits each conduit run to 9 conductors (4 circuits: grounds and MWBC neutrals do not count) unless you upsize conductors. I'd use the biggest boxes I can get, no smaller than deep 4" 2-gang boxes, because they will be full of splices. I use THHN/THWN through the conduit to the panel. Terminate grounds at the ground lug in the junction box, or run a wire. EMT is a ground path.

But try this. Leave the panel where it is, and install a sub-panel in public or tenant space. In fact, forward-think: if in the future you wanted to set up the tenant with a separate meter, what could you do now (cheaply) that would make that cheaper and easier later? Setting them up with a sub-panel easily converted into a new main panel, would be awesome all around. This isn't necessarily a large investment, mostly just forethought to not paint yourself into a corner.

Honestly I'm surprised your GC is trying to feather-bed the project with unneeded work when the sub-panel is a really worthy effort.

Answer 2

I think the point here should be never take electrical advice from a General Contractor. Get your advice from an experienced electrician.

There is absolutely no reason to replace all the wiring in the house. Upgrading or moving the service does not require a complete re-wire. Fire is about the only thing that requires a re-wire.

If you want to keep the existing panel, as a panel, then Harper's advice of leaving the panel and using it as a sub-panel is a good idea.

If you don't need the panel and just want to extend the circuits to the new location, you could use the old panel AS the junction box and have a sheet metal cover fabricated for it. Of course it would need to continue to be accessible since it is now a junction box.

Good luck with your project!