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I am building a cabin, we had a discrepancy with someone down at the property about wiring. I am feeding the cabin off the main breaker with a 50 A double pole breaker only using 120 V (single pole of the breaker) fed by a 6/2 UF wire. My neighbor said that only using one pole of a double pole is dangerous, even though they work independently as breakers and both will flip if one does. So he took it soon himself to use the 6/2 wire to rig the other pole. Black and white both hots and the neutral as the bare copper ground and no ground from the main panel. I’m ticked off but is this safe? Or should I make him buy me new wire to run?

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    We cannot answer whether you should "make" your neighbor replace the wire. This isn't the forum for that, and regardless you haven't provided enough information about your neighbor's role in all this. You should remove that part of the question. There are two good remaining questions here, both already answered -- whether you can/should use the existing cable for one-pole (sure, if you want) and for two-pole (no) operation. If there are things that require two pole service, you haven't said so. But if so, you need a new cable.
    – jay613
    Commented May 22, 2023 at 16:17
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    What does your neighbour have to do with your property? Are you co-owners ?
    – Criggie
    Commented May 23, 2023 at 22:35
  • As this touches on some building code areas you should add a rough location tag or description to let people answer. While what is safe for electrical work is universally true, what is recommended or legal varies by political area. I assume you are speaking from the USA but as others have pointed out lots of States have different rules. In the UK the "correct" answer is no to the use of a ground a neutral (but you can make part of a 3 phase supply into a neutral using a well grounded wire in certain circustances).
    – TafT
    Commented May 24, 2023 at 15:47

4 Answers 4

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Absolutely not. Completely illegal.

You need a ground WIRE even if your buddy doesn't know that. A lot of people are stuck in 1966 (1996 for dryers; 2008 for outbuilding feeders) and think neutral and ground are the same thing, or that a ground rod will substitute for a ground wire. Nope, and NFPA has the toe tags to prove it.

And, it's not sufficiently insulated for the task anyway. Neutral needs insulation.

My neighbor said that only using one pole of a double pole is dangerous. even though they work independently as breakers and both will flip if one does.

Complete poppycock. It's perfectly fine to use one pole of a 2-pole breaker as a single. (assuming it's a modern breaker and not Federal Pacific; those tended to "tram" when one side tripped, freezing motion for both sides and thus sticking on - that's why they're gone).

In fact I recommend that when wiring 120V/30A travel trailer outlets, because a 120V/30A breaker is utterly useless except for TT outlets, and a 240V/30A breaker is useful for all sorts of loads including EV charging.

You need a license to do electrical work

So he took it soon himself to use the 6/2 wire to rig the other pole. Black and white both hots and the neutral as the bare copper ground and no ground from the main panel.

Wait. What? He did this? Check your state law but I'm pretty sure it's illegal for anyone but a licensed electrician to do electrical work, unless they are the homeowner and will be occupying the home for at least 6 months (sorry flippers). There are exceptions for low voltage (doorbells; USB powered cams) and for trivial socket or light fixture swaps, but certainly not configuration of feeder wires.

So no. Put it back the way it was, and ban the person from the property. If you find yourself in a political bake-off with the guy, then call the city inspector to tie-break. Once your buddy hears the city inspector is coming, the guy will suddenly disappear.

I’m ticked off but is this safe? Or should I make him buy me new wire to run?

Well... I really wish you'd talked to us before buying any wire, because you could've gotten the best of both worlds for half what you paid.

But no! Your buddy didn't promise you 240V and doesn't owe you 240V. Clearly your original plan was to run 120V/50A feeder to the cabin. FINE - my winter cottage has 120V/30A and that works great. So yeah, just go back to your original plan.

But even in a fantasy world where your buddy owes you wire (promised you an electric dryer?) then it won't be expensive, ask us the best option after mentioning your loads.

If your buddy is the owner of the panel, then the host is free to add additional rules beyond NEC, and if they say "you gotta take 240V and not use half the breaker" then that is a lawful demand. It'll be on you to run 4-wire cable in a legal manner. (obviously, they can't be counted on.) Did you trench it with 24" of cover (or 18" in conduit)? If not, then it's wrong anyway.

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  • To be fair, "tramming" is one of the reasons FPE is gone. Which BTW, I'm pretty sure FPE stands for "Effing Piece of Excrement". Spot on answer. :) Commented May 23, 2023 at 20:58
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UNSAFE!!!

There are three problems:

  • Bare Neutral

There are certain situations, including feeder to the meter and from the meter to the main panel, and some grandfathered-without-ground branch circuits for ovens where a bare neutral is OK. But in general usage on branch circuits, bare neutral is not OK. Why? Neutral carries current, so there is a danger if someone touches a bare neutral in certain situations. In addition, neutral and ground are supposed to be separate except in the main panel, so a bare neutral that contacts ground (e.g., grounded metal box) would cause lots of trouble.

  • Neutral Too Small

6 AWG UF cable, as with most cables with wire larger than 10 AWG, has a smaller ground wire than the other wires. For example, Southwire UF 6/2 has a 10 AWG ground wire. A 10 AWG wire is only rated for 30A.

  • Missing Ground

For decades, ground has been both required on all circuits and required to be separate from neutral except in the main panel. Ground is vital to both life & fire safety. There are some code-sanctioned workarounds on smaller circuits - e.g., GFCI in lieu of ground. But for new stuff ground is required just about everywhere, and certainly including your situation.

So you can't use a bare wire as neutral. You can't get rid of ground. You can't combine neutral and ground (that's the 3-wire dryer issue, which has been against code since 1996).

There is nothing inherently wrong with everything on one leg, as long as you know how things are wired (e.g., if you run the one hot to both legs of a subpanel then 240V circuits simply won't work but MWBCs are not allowed because they would work but run a risk of overloading the neutral). It is not great because it means your utility feed is not being used in a balanced way, but at the small level it should not be a big deal.

Your options are to switch it back to the way you had it (perfectly safe, not ideal in terms of load balance) or change to a hot/hot/neutral/ground cable. Unless there is a local prohibition against aluminum (generally allowed for feeding subpanels at this size), your best bet is probably 2/2/2/4 aluminum cable. That is good for up to 90A and solves both problems.

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    3. Undersized neutral, the grounding conductor in regular cable in the USA is smaller than the current carrying conductors. This is ok for a ground that only carries current under fault condition, but not good for a neutral that may carry full load current. Commented May 22, 2023 at 17:42
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simple answer: UNSAFE AND ILLEGAL

  1. Your neighbor is wrong when he says that it is unsafe to use just one half of a two pole breaker. If either side of the breaker detects an over-current situation, the whole breaker should trip, same as a single pole breaker and same as a three pole breaker.

  2. If you need 120V at the cabin, you can connect the black wire to one half of the two pole breaker, connect the white wire to the neutral bar, and always connect the bare copper to the ground bar. There is no safety issue here, perfectly safe. (I believe this is what the original poster did)

  3. If you need 240v at the cabin, connect the black wire to one half of the two pole breaker, connect the white wire to the other half of the two pole breaker, and still always connect the bare copper to the ground bar. Perfectly safe. (I believe this is what the neighbor changed it to)

  4. If you need both 120V and 240V at the cabin, the 6/2 is not enough, you will need a 6/3.

  5. You should never use the bare ground wire as a neutral, and more generally you should never use the bare ground wire as anything other than a ground. It is definitely NOT safe to use the ground to carry electricity because it can create a shock hazard everywhere that the ground wire goes and anything metal that it touches (such as electrical boxes, metal appliances, etc). The ground is there only to be used when there is a fault in the wiring. There are some minor exceptions such as pilot lights on extension cords and similar scenarios, but then the amount of electricity flowing through is tiny and most people wouldn't even feel it, and it wouldn't be enough to hurt anybody.

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My neighbor said that only using one pole of a double pole is dangerous.

No

There should be a metal tie between the breaker handles. If one side trips, both flip. That's by design. The downsides of this sort of setup are

  1. Wasting money. A double-pole breaker is more expensive than its single pole counterparts. The money is already spent here, so this point is moot.
  2. Wasting space. You could fit something else inside that slot.

There's no safety factor here.

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    Common-trip is normally implemented entirely internally - the handle tie is irrelevant. Breakers are also normally "trip free" - they will trip internally even if the external handle is physically jammed to the "on" position.
    – nobody
    Commented May 22, 2023 at 23:33
  • @nobody yeah exactly. The handle-tie only serves maintainers. Commented May 23, 2023 at 21:22

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