Electrical – Best Way to Bring Wire from Flush-Mount Panel to Surface-Mount Conduit

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I often see people with a flush-mount panel in their garage who want to install some EV charger or NEMA 14-50 receptacle that requires new wiring from the panel.

Unless the desired charger / outlet location is in the same stud bay as the panel (e.g. immediately below it), it's painful trying to run the full length of wire inside the wall through several studs until the desired location. It's much easier to use surface-mount conduit to make the full trip.

I'm aware of 2 ways to "break out of the wall" from a recessed breaker panel to surface-mount conduit going somewhere else:

In-wall wiring from the panel to a metal box in the same stud bay (e.g. below the panel), then add a metal extension ring on top of the box with a blank cover, and use one of its knockouts for exiting via conduit.
Flexible conduit starting from a knockout at the top of the panel (in-wall), and curving and exiting from a hole above the panel. That hole can then be foamed closed.

Out of these, #1 sounds much cleaner and simpler to me.

Are there other common ways to do this? Or other trade-offs with these or other approaches that are worth knowing about?

Best Answer

#1 is easier and looks better than #2. I'd be using EMT, electric metallic tubing, insteaad of PVC.

#2 is also used extensively but not with the sealtite flexible conduit. Regular flexible metal conduit is used more often and is also cheaper. See picture below from Granger.

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Electrical – Proper way to protect cables above surface-mounted electrical panel

Surface wiring is often allowed in areas not readily subject to damage. I'm surprised it was flagged. The panel in my unfinished basement from 1993 has a fountain of cables coming out of it and it is (was) considered acceptable.

I'm no code wizard, but I'd put lumber alongside the cables, flush on the sides of the box, between the box and the ceiling. I'd overlay a small piece of plywood (using screws to keep it removable) and call it done.

--------------------------- < -- ceiling
   ||    |   |   |   ||
   ||    |   |   |   ||
   ||    |   |   |   || < -- framing lumber with cables between
   ||    |   |   |   ||
   ||    |   |   |   ||
   -------------------
   |                  |
   |                  |
   |                  | < -- electrical panel
   |                  |

Cables need to be secured as they would anywhere in a circuit: Every four feet and within 12" of the box. Since they should already be clamped at the panel entry point, you really only need to staple up near the ceiling. If there's a gap behind the cables where they enter the ceiling, install a board of suitable thickness crosswise behind the cables and staple to that.

Electrical – how to replace surface conduit for a two-wire lighting circuit

First, is actual neutral present in the switch box? That's a requirement now, so if it's a switch loop you'll need to re-run it with /3 cable.

Now the purpose of grounding is to

return natural electricity (lightning, ESD doorknob zaps) to its source (earth via the grounding electrode system), and
return artificial-electricity fault current to its source (via the equipotential bond to neutral back at the transformer).

You've created an island of ground. All it'll do is distribute ESD and fault currents to other places in the island. I talk about the badness of that here.

Easy to fix: Retrofit ground to connect your island to your house's grounding system. In 2014 they liberalized the rules to make it much easier. More on how to do that, here.

To answer your questions:

I agree, this is wire repair, not expansion of the circuit.
Grounds should be run home as I describe.

Also, whatever circuit(s) are still on knob & tube, slap an AFCI breaker on them. This will trip on any wire arcing, which is the usual problem people worry about with K&T.

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