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Working on a family home remodel, there is a 20 amp circuit with 12 gauge wire. Recently, at the end of the run, 13 LED can lights were added in an inaccessible vaulted ceiling with no attic space. The LED’s were added with 14 gauge wire.

The max load of the lights is a total of just under 2.0 amps. I have confirmed there are no devices downstream and it’s not practical that anything would ever be added downstream from these lights.

Other than to be code compliant or to reduce risk of hazard if overloaded, is there a compelling reason to actually rip all this out and rewire to 12 gauge? The remodel is not being inspected and the home is NOT being sold anytime soon.

This topic has been well addressed, I’m not looking for a debate of code and the obvious. The purpose of my question is to uncover any practical knowledge of why this IS or IS NOT a true problem in the real world of remodels. We will note the actual as-built issue to reduce the chance anyone ever attempts to add additional load on this 14 gauge branch of the circuit.

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    Depending what else is on the circuit, just lights or an outlet for higher amp device, might just be easier to switch the breaker to a 15 amp. 14 gauge is good on 15 amp breakers, so is 12 gauge.
    – crip659
    Commented Dec 6, 2022 at 16:10
  • @crip659 Great point - I should have mentioned that. We are looking at that as well. My only hesitation is this is an older condo (1970’s) with a very limited panel so each circuit has quite a few “items”, however, this is something to consider.
    – Richard
    Commented Dec 6, 2022 at 16:14
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    Since it is older the lighting circuits would have all been sized for incandescent. Unless there's some big fixed consumer on there a 15A breaker should be fine. Right now, for example, my whole house with two people active in it is only using about five amps, excluding the heat pump.
    – KMJ
    Commented Dec 6, 2022 at 17:21

3 Answers 3

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Except when there is an actual danger right now (there isn't), the problem is always the future. It is extremely unlikely that any future homeowner or electrician doing additional work will notice the 14 AWG wire. An electrician working on it should notice the 14 AWG wire, but a homeowner very well may not. So the concern is that in the future someone decides they want to add another receptacle in the room with 14 AWG lights. They tap into the switch box (assuming they don't want the receptacle switched with the lights!) and run a cable to the new receptacle. They're just planning to use it for phone charger, laptop computer, desk lamp, etc.

But then the next person decides to plug in a space heater when the HVAC is broken. And actually plugs in 2 space heaters because it is getting really cold, and because they don't realize you shouldn't do that. Each space heater draws 12A (that's the standard in the US for a 15A circuit with continuous usage). Two of those (24A) on a 15A breaker would be 60% over and trip in a few minutes, before the 14 AWG wire heats up too much. Two of those on a 20A breaker would be 20% over and might trip in a while (10 minutes or more) or possibly might never trip because of the way breakers are designed (some tolerance for moderate overcurrent, manufacturing variance, etc.). Meaning you have now created the situation for a major failure.

In my own house when putting in a new panel (permitted, electrician did the real work), there was one circuit on a 15A fuse in the old panel. Clearly 12 AWG wire coming out of it. Unknown whether somewhere else in the house (some of the circuits go all over the place) there might be 14 AWG wire, therefore did not up-size to a 20A breaker. That's a little different case, but the point is the same.

There really are only two options:

  • Replace the 14 AWG wire with 12 AWG wire.
  • Replace the breaker with a 15A breaker.

Anything else is, long-term, a huge risk.

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    Great full scenario explanation. I did’t think the “usual” response to this question would sway me, but you’re 100% correct and reading it convinced me to just bite the bullet and replace the wire or step the breaker down (likely). It’s one of those items that normally will not cause an issue, but if it does, it can be really bad. Thanks
    – Richard
    Commented Dec 6, 2022 at 17:04
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    And even worse: Insurance might not pay for damages and/or sue you for non compliant electrical work. Even in places where homeowners can do their own electrical work, they have to follow the rules. Commented Dec 6, 2022 at 17:07
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    And if you go the breaker change out, add a note in the main panel as to why you did it so a future owner won't change it back to a 20.
    – JACK
    Commented Dec 6, 2022 at 17:46
  • The receptacle (or lack thereof) seems key to the likelihood of ever overloading that branch. That's one reason to keep lighting on its own separate circuits.
    – MarkHu
    Commented Dec 7, 2022 at 20:00
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In the real world you can't control what crazy-seeming thing the next guy is going to do 20 years down the line. What seems unlikely to you today (extending the circuit off the end of that 14 gauge wire), may for some reason look like a good idea to someone else in 20 years.

If you change over to a 15 amp breaker now, then changes down the road will require at least one extra screw-up to create a dangerous situation.

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    And, sadly, the "someone else in 20 years" could be you in 2 years because, you know, life got involved and you forgot what you did 2 years ago...
    – FreeMan
    Commented Dec 6, 2022 at 19:28
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    @FreeMan What did I eat for dinner? Where are my keys? Did I lock my door Commented Dec 7, 2022 at 3:47
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You could just pull the 20A breaker and put in a 15A breaker. That's the easy, code compliant solution. Also 14AWG won't set on fire until it's got 50-60A passing through it. Heat and age come in to play if it were to continuouldy and frequently see too much current the insulation could wear down over time and expose you to some risk. When in doubt, for all things safety related, I say take action and make them right. when you adopt the mindset of "it'll be fine" and cut a corner, you're gambling. If you gamble enough, you're a gambler. You will lose one day, ask any gambler. Will it cause a fire? I highly doubt it. doubt isn't certainty though... good luck, and change that breaker, ya hack!!! ;-)

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    This doesn't really add anything that wasn't already addressed many hours previously. (Note that the other 2 answers both say this, but that they were posted within about 1 minute of each other - they were being typed at the same time.) If you'll look through the help center, particularly on answering, you'll note that we prefer answers that add new info or a different perspective, and don't just repeat others.
    – FreeMan
    Commented Dec 7, 2022 at 12:40
  • I appreciate this concise answer. Not bothered if the facts are embedded in longer prior answers. Clear wording matters.
    – MarkHu
    Commented Dec 7, 2022 at 20:02
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    @MarkHu, how is "continuouldy" clear wording? :) Commented Dec 7, 2022 at 22:54

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