I’m hoping some of our US-based DIY Dopers can help me out with this: I’m trying to run some new wiring and outlets in my basement so that I can put an upright freezer down there, plus I’d just like a couple more outlets anyways (there’s only one in the main area). However, I’m not sure about how safe my current (ha!) setup is:
The previous owners had a creepy indoor barrel hot tub down there. It was wired in a terrible manner: there are two 15A breakers in my breaker box that lead to the junction box that fed this hot tub using grounded 10/2 wire. I think the hot tub needed a 240V connection, and this is the shitty way that they did it. Right now, I have those breakers switched off and the two 10/2 wires capped off in the junction box.
What I want to do is get either 12/2 or 14/2 wire (with ground wire, of course), and junction it to one of those 10/2 lines. From that junction, I want to feed 3 or 4 15A receptacles: one for an upright freezer, and the other three for general usage (lamps, maybe a TV eventually, and the Shop Vac once in a while).
-Can I junction the smaller wire to one of those 10/2 wires without a problem?
-Can I feed a 15A receptacle with 12/2 wire?
-Do I need to have a pro come out and upgrade those 15A breakers with 20A breakers and replace the 10/2 with 12/2? I read somewhere that 10/2 should be coming out of a 30A breaker, 12/2 a 20A, and 14/2 is used for 15A breakers. Is it a problem that I’ll have 15 feet of wire that’s too large of a gauge in this run?
I’ll just say that you shouldn’t do anything else until you get that hot tub wired properly. You should contact a mod, this could go into the General Questions forum.
Oh, sorry that I left that dumb detail out: the hot tub is long gone. The idiots had left the wires hot in the junction box, though, so I turned off the breakers and capped the lines. Now I want to use one of those lines to feed new receptacles.
Yes, just make sure you use the correct size wirenut or connector. (Read the package to see what the maximum number and gauge is for each connector.)
Yes.
Too large is not a problem - BUT your breaker must be sized for the load limit of the smallest wire on the circuit. If you’re using 12/2, then a 20A or 15A breaker will be fine. Since it’s a basement, I would recommend using a 20A breaker with 20A GFCI receptacles. (This may actually be required in your area.) You could also use standard 20A receptacles with a GFCI breaker.
You can replace the breakers yourself if you’ve got a way to shut power off to the panel. (Or if you’re brave.)
I’m certainly no electricity expert, but it reads to me like there could be differing opinions on whether the OP will “have a problem” with some of his ideas, so I’m going to leave it in place for now.
If enough people feel strongly that these are one-answer-only factual questions, I will be happy to revisit the issue.
This is generally frowned upon since someone could look in the breaker box at some later time and see the 10/2 wires connected to that breaker, and they could think that they could safely put in a larger breaker instead, not realizing that part of the circuit uses smaller wire.
I don’t think it actually violates code, though, and functionally the larger wire won’t be a problem. In fact you’ll get less wire losses due to the heavier wire gauge through that part of the circuit.
I was thinking about that, actually. I’m not sure I’m comfortable upgrading the 15A breaker to a 20A, since it may be a 15A for a reason, but I might go in and take out the two 10/2 wires and replace them with 12/2. This would also let me make a home run from the breaker box to the first new outlet I run, right? Or should I still go Breaker box --> Junction box --> Receptacle box?
If you are removing the 10/2, I would also remove the junction box, it really doesn’t serve a purpose other than a possible point of failure (not likely but possible).
Code may require a separate circuit dedicated for the freezer. I really can’t remember but it is something to verify before you move forward. It has been a long time since I used the code for residential construction.
A 15 amp breaker requires #14 wire or larger. A 20 amp breaker requires #12 wire or larger. A 30 amp breaker requires #10 wire or larger.
#10 wire does not require a 30 amp breaker.
You can use the #10 wire and the 15 amp breaker with no problem. Me I never use #14 wire in my house only #12. that way if I want to I can up size the breaker.
If the home run from the junction box to the panel is short then maybe remove the box and new home run, but if there is any distance then leave it alone and use it. Why waste money. If you are going to put in more than one outlet and daisy chain from box to box do not daisy chain through the outlets. Connect only one hot, neutral, and ground to each outlet.
As to why two 15 amp breakers were use for the hot tub sounds like they installed on the cheap. Probably had the breakers on hand along with the wire.
I have the same question. Almost all outlet wiring I’ve seen was daisy chained from outlet to outlet. My house is a rarity, it’s a log cabin, there are no hollow walls to run wiring in, for most of my outlets I have boxes daisy chained in the basement with a single cable running vertically through the floor to outlet boxes on the wall.
Also, I don’t know if it’s code, but the electricians around here will always match the wire size to the breaker. They say the inspector requires that, but I don’t know if that’s actually in the code as opposed to the way they were trained in order to avoid potential problems. Of course codes vary, they don’t always make sense, but to err on the side of caution isn’t a bad thing.
This is called pig-tailing, and is the superior method. The running line then connects via one wire nut, which are highly reliable.
If you daisy chain through the outlets, then the running lines have two screw or speedwire (god forbid) connections in series, or 4 if you consider hot and neutral, and also through the break-away tabs on the outlet, which are not at all over-sized.
You also have to pack 4-6 solid wires (what did you do with the grounds?) into the box as you install the outlet into the box, rather than 2-3 possibly stranded ones.
You can buy pigtailed wire nuts to facilitate this. These have a stranded pig tail terminated with a crimped spade lug coming out of the pointy end, so you only have to get the nut onto the incoming and outgoing wires. IME “real” electricians eschew these…two more things to run short of on a job.
Both actually. While the code itself doesn’t specifically require the wire and breaker match, it does require specific or greater wire size to the breaker as Snnipe 70E said.
The Electrical Code is at the Federal level, but each state and/or municipality can make it more strict, i.e. wire size must match breaker.
and
Most electricians are trained to, and mostly out of habit, match wire size and breaker to avoid problems later. Having to fix something later at your cost isn’t good business.
Most simple electrical repairs are well within the capabilities of a reasonably handy homeowner. Nothing wrong with asking questions to make sure you do it right.
I think that generally, it boils down to 14 awg is less expensive than 12 awg, so the thinking is why spend the money to wire for 20 amp circuits when you’re going to use a 15 amp breaker? I’d suggest the OP determine what current the freezer needs and work from there.
