Thanks guys! Will try this today. If I stop posting forever, it’s because your bad advice got me electrocuted and I’m dead!
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I’ve already answered him elsewhere, but MaxCut is onto it there. The 60A is almost certainly to a subpanel somewhere that feeds the microwave circuit.
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Good news, everyone!
So here is my situation. I have a pretty large room that I had a guy put some recessed lights in. He’s not an electrician, but he does a bunch of work on my house and always does a good job.
Anyway, twenty light fixtures were installed in this room. All LED (if that matters). He mentioned at some point that when adding that many lights, something needs to be done to the breaker box. I forget what exactly. I’m a bit reluctant to have him handle that part of it because my panels are a complicated mess. I’ve got a generator that some of the circuits are on and there are some other oddities. I’ve got an legit electrician coming over in a month to do some other electrical work and I might have him address this then.
So here are my questions.
- Is this something that can wait a month? Is the house going to burn down before then.
- Can someone explain to me what exactly needs to be done. You’re gonna have to ELI5 it.
I’ll throw out the @microbet batsignal, but I’m sure he’s not the only one who can help me out.
Only a certain number of those lights can go on one circuit. He’s probably saying 20 is too many. Running a new circuit can vary a lot in how hard it is. It’s not the complexity at the panel that’s the issue, it’s physically running the wire. If there’s an attic it might not be too hard, but still could be. The panel could be full and that might make it harder.
The danger? The circuit probably still has a breaker and if it’s properly sized (it shouldn’t have had to be changed) the risk is supposed to just be that you trip the breaker if it’s overloaded. It’s not impossible though that running current just below what it takes to trip a breaker for hours could get wires pretty hot. But it really shouldn’t cause a problem. That’s what breakers are for. A poorly made connection though and all bets are off (unless you have arc fault breakers).
Now if someone said “oh, this breaker is tripping, I’ll just put in a bigger breaker” that’s when you can get a fire.
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Thanks for the reply.
How do we know how many is too many? Is there some way to calculate this?
Couple more questions.
I actually asked him about running wire and he seemed to suggest that really wasn’t an issue. It was something he had to do in the panel. I’ll ask him again if he can explain what he intended to do and I’ll report back.
So are you saying if I just use the lights as normal and there is no breaker tripping, then I’m good?
It’s possibly in the installation manual. It might just be the current rating in amps. It might just be the watts. If it’s the watts, divide by 120 (volts) to get the amps. Add the amps of each light. (x20) If something might be on for more than 3hrs (like lights) you size for 80% of the rating of the wire, so divide your amp total by 0.8.
The wire is probably #12 in a newer house and that’s rated for 20A. In an older house (or some newer) you might have #14, which is rated for 15A.
But…you probably don’t know if the handyman just grabbed some wire that was up there that has other lights or outlets on it. Well, outlets maybe. Lights you’d figure out because the switches wouldn’t work as expected. And this is likely because it sounds like a new circuit was not run.
There are some other things which could affect how much current you can put on a wire like how many wires there are in conduit, if there’s conduit, ambient temperature, and length of run, but those probably don’t apply here (conduit fill maybe if it’s an old but not too old house).
There were no manuals read by anyone.
As far as the wiring is concerned there were a couple of lights that were already in the room. So he hooked up the new lights in series with the old lights. The only new wiring was the wiring between the lights.
So those lights are on the same switch? Anyway, gotta count the amps of those lights too. And you still might not be sure if it goes from an outlet to a switch to all those lights. If it’s like a 30yo house or less, it’s probably not too crazy. The older the house the more weirdness you are likely to see added on. You are adding a little weirdness. In 20 years someone may add some outlets to that circuit and they will have to turn the lights on to use the toaster.
OK, I just took Amps off the boxes the lights came in. There were 10 smaller ones that said 12 amps and 10 larger ones that were 13 amps. So that gives me 250 Amps total.
250/120/0.8 = 2.6 Watts.
Did I do that right?
2 separate switches. One was an existing switch to old lights. He made a new switch for the other ten lights by tapping into a wire that was going into an electrical outlet. However he said that the switch won’t affect the operation of the outlet. I just tried it out and it seems like outlet works if lights are off.
12A is for all 10 of those lights. You’re at 25 amps total and that’s too much for one lighting circuit. You need two.
The thing where the wire came off an outlet? That outlet is on the lighting circuit now. If your lights are on and you plug a vacuum cleaner in you might trip the circuit.
There’s often no easy solution to this and that’s why older houses end up with tripping breakers sometimes. If you have to break open walls to run new circuits it gets expensive.
So if it was 5 lights or 10 lights, it would be 12 A total either way?
Fortunately I don’t think I have ever used the outlet even once. However, it is very possible the folks that we hire for cleaning do plug a vacuum cleaner in there. I guess I’ll find out.
Yeah, I was definitely trying to get this done on the cheap.
Thanks again for all the responses. But circling back to the original concern. If I’m just using everything as normal and no breakers are tripping, then is there anything I need to worry about?
Shit, I realized I fucked up the calculation.
The lights say 12W and 13W (not amps).
So 10 x 12 W + 10 x 13 W = 250 W
250 W / 120 V / 0.8 = 2.6 Amps
Is that right?
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Probably not. It’s probably ~0.83A/light. I just know it wasn’t 12A/light because that’s enough to power a hammer drill and 250A is probably more than your house can supply. So, I’m assuming the 12A on the box was for all 10 lights.
Eh, vacuum is probably like 5A. Probably will be ok.
Sorry, the best I can say is “probably not”. I wouldn’t worry, but I practically have ataraxia.
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Just make sure no one is putting on bigger breakers so things don’t trip.
Old old houses had these fuses called “Edison fuses” that screwed in like a light bulb. If they blew out often some people would shove a penny in there and that was called a “Lincoln fuse” which was no fuse at all.
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I actually remember those. I had them in the first house I lived in growing up.