Home run wiring

I recently did an re inspection on a home that had ungrounded three prong receptacles. The electrician installed a GFCI receptacle on the first receptacle in the circuits, and labeled them as GFCI protected, and no equipment ground installed. Awesome.

I was just curious how electricians find out which one is the first receptacle. I have heard electricians call the wiring from circuit breaker to the first device, the home run.

Sometimes it is just an easter egg hunt to find the start of the circuit. Everything on the circuit must be identified. Sometimes it is just wherever is closest to the panel.

So there isn’t any trick?

Why not just install breakers then? Wouldn’t the man hours saved be worth the additional cost?

A lot of times the homeruns involve MWBCs and a GFI breaker won’t work.


I normally take the cover off of the one I think is last as it only has one set of wires since it’s the end; not always the case, though.

Most homes I inspect only have one MWBC , and it doesn’t need GFCI protection.

Are they more common where you are?

But how how does that help finding the first one?

I would find the correct circuit, shut off the CB and then find the receptacle closest to the panel that was off. I would say that the majority of the time that’s the first one. If the cable is visible leaving the panel, like in an unfinished basement, you can trace it to the area where it goes up into the wall. I agree you could waste hours just looking for the first device. In that case a GFCI breaker would work. A MWBC would require a multi-pole GFCI CB.

So before adding in the GFCI receptacle, do you take out the old one, turn the CB back on and make sure everything downstream is off?

Do you have to map out the circuits first, or do you just assume the panel label is correct?

I’m just curious. It really doesn’t pertain to inspections. I was just impressed by the electricians work.

To find the circuit I would use a circuit tracer first and then go on from there. If you’re speaking of NM cable without ground you’re looking at an old installation. If there hasn’t been much alteration to that old wiring tracing it can be pretty easy.

Gotcha. I think I get it now. Thanks!

This one was easy…:wink:

Thats just friggin brilliant right there. :wink:

Going to start seeing that more when AFCI protection is needed on a receptacle replacement.

Yes agreed and that is what I find also many are doing here at least. However they still did not do it right.

What is wrong with that set up?

I will send it to my Master Electrician OK Juan.:wink:

You say they did it wrong but you still need to farm this out to figure out why? If you know it is wrong why do you need to involve another party? Please tell me again what CMI means.

To Juan, the issues I see are the cables are not properly secured and depending on code cycle the GFI may be mounted too high to be considered readily accessible.

No I do not need to farm it out. I find it retarded to discuss the obvious. I will not engage as I do not hold a position as a Master Electrian.
However both of your comments are correct.

Then how do you explain yourself commenting in the first place. Why even bother commenting? :roll:
Don’t bother answering, we all know the answer!