I recently discovered that an electrical outlet in my attic somehow had two separate electrical circuits running to it. By this, I mean two circuits on two separate breakers running to the same outlet. My inspector was testing the outlet, and when he tripped the GFCI and then pressed the reset button, the outlet made a spark and the breaker powering the whole sub-panel to my home tripped.

My home builder's electrician came out to fix the issue, and what he did was disconnect one circuit, cap the ends, and then tucked them into the outlet.

Through this whole process I discovered that the circuit feeding my furnace is also powering the attic outlet mentioned above, attic lights, the lights in my utility room, and one outlet in my utility room. Is this up to code? Should the furnace unit in my attic be on its own dedicated circuit?

By "furnace unit" I mean the actual furnace and air handler/coil unit for the A/C which are in my attic.

For reference, below are pics of the breakers connected to the circuits mentioned above.

The load -probably- works to have a light, a couple of receps, and the furnace on the same circuit but 99 times out of 100 it should be separated.

To trip the breaker feeding your subpanel it was a good ol fashioned dead short, one to get enough fault current the branch breaker didn't catch it. Was that GFCI working before he hit the test button? Seems like it would tripped and tripped in a MF hurry if it was on before he reset it.

Also smells like someone got cables crossed coming out of the panel and used the furnace circuit instead of the receptacle circuit. Electrician should have capped the furnace circuit at that receptacle and should have disconnected it and capped it at both ends. He should also do the next guy a favor and label it dead.

I don't know if the GFCI outlet in the attic was working prior to this since I never used it. I only discovered this problem because I had an inspection done.

I am definitely thinking wires got mixed up, and I'm trying to get their best electrician out to look at everything. If the code is to have the furnace unit on its own circuit, then I want to be able to leverage that to make them fix it the right way.

My thought is that they definitely got some wires crossed up there because the breaker labeled utility/garage/attic should definitely be powering everything currently on the furnace circuit that's not the furnace.

I think the breaker labeled utility/garage/attic is tied to the circuit that he capped the ends of because if I turn it off I can't find anything in the house that's dead.

422.12: Central Heating Equipment.

Central heating equipment other than fixed electric space-heating equipment shall be supplied by an individual branch circuit.
Exception No. 1: Auxiliary equipment, such as a pump, valve, humidifier, or electrostatic air cleaner directly associated with the heating equipment, shall be permitted to be connected to the same branch circuit.
Exception No. 2: Permanently connected air-conditioning equipment shall be permitted to be connected to the same branch circuit.

Thank you! That's the NEC right?

Yes

What year was the house built ?

I have seen a 1980 house where the hvac equip in attic had a 110 plug and then it also dropped down and fed the bathroom gfci outlet

House is about a year old

I'm not sure what to do next. The electrician came out again, and I explained the need for the furnace to be on its own circuit. The electrician's boss was called, and he confirmed the need for the furnace to have it's own circuit because this electrician kept trying to tell me it was fine.

There is quite a mess with the wiring in the attic. In the pic below, the plug for my furnace is in the foreground, and you can see it has two wires leaving it. Apparently the wire that's sloppily strung across the floor is feeding the power to the furnace, and the other wire heading into the floor goes to my utility room to power some lights and another outlet.



The electrician wanted to splice some wires together in the outlet in the background as well as in the outlet in the foreground in order to have pass through wires to give the furnace its own circuit and maintain the circuit to the utility room as well. Is this safe or a good solution?

I'd rather they run a new wire straight to the furnace instead of having all these splices inside the outlet boxes and multiple wires running along the floor, but that will likely require cutting into drywall to run a new wire.

What a mess...

You can run different circuits in the same box, but it'd be better to add a second junction box or two for the splices and separate the circuits. Super easy and very cheap to do, especially in an open space like this attic.

The splices wouldn't concern me, but the workmanship here does.

BenTheGoodAg said:

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What a mess...

You can run different circuits in the same box, but it'd be better to add a second junction box or two for the splices and separate the circuits. Super easy and very cheap to do, especially in an open space like this attic.

The splices wouldn't concern me, but the workmanship here does.

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Thanks, I may push them to do that. Where would you place the junction boxes?

What could be done to improve the workmanship? I want to make a list of all the potential issues.

I don't know what they were thinking running a cable right through a maintenance area like that. It's not secured (both at the ends near the boxes and throughout the run). It shouldn't be on the floor. The way it's crinkled up, it's obvious they're not used to unspooling romex. There's no reason a new build should look like that.

The new boxes could go right next to the existing boxes. Btw, a box is like $1.

Yeah I am pretty annoyed about that wire running along the floor where people working on the A/C will have to pass over and step on it. The builder's electrician is particularly annoying because when I talked to him he wanted to run a second wire along the floor next to it because that's the easy way to do it.

Not sure the solution to that other than removing that wire and making a new run to the furnace from the breaker box, but then they also have to figure out how to serve the wire running into the floor another way as well because it was being sourced from the furnace plug.

If there was a way to fish the wire under the attic floor, even though it would be loose under there, would that be acceptable?

Personally, that's what I would do. You might get an inspector that doesn't like it, but it's typical when you retrofit to do that.

I'm sort of dumbfounded they did that on purpose. There's some subjectivity in the 'physical protection' requirements of the code, but to me, running on the floor like that is pretty far out of bounds. Maybe that's typical in attic installations elsewhere, but I doubt it.

One of my friends familiar with the code said that our city is on the 2020 NEC, and it would be up to code if it was going along the floor with pretty much anything like a conduit or a 2x4 on the ground that the wire is protected by. Anything that would prevent it from being stepped on directly.