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Can I wire sockets with 18gauge wire for 40watt bulbs?
fadingathedges
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Registered User regular
I have two light fixtures that I am rewiring the sockets on - one four socket fixture and one five socket fixture. I only use and intend to continue using 40watt bulbs. I believe each is wired with a basic 110 jigawatt line. Is the 18 gauge wire I bought gonna do me right? The 16 was much fatter and I didn't like it.
Bonus point question: Can one still buy the rope-style wires, without the asbestos of yore? I'm picturing a modern wire with an aesthetic cord casing - it seems like someone should have done this.
e~ I don't know anything else about my circuit box except that the house is old as balls and probably was at least partially rewired several times.
Bonus point question: Can one still buy the rope-style wires, without the asbestos of yore? I'm picturing a modern wire with an aesthetic cord casing - it seems like someone should have done this.
e~ I don't know anything else about my circuit box except that the house is old as balls and probably was at least partially rewired several times.
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Looks like 12 is the standard for sockets, 14 for lights, and 18 for low voltage lights.
http://electrical.about.com/od/wiringcircuitry/a/electwiresizes.htm
Seriously though, Google results are telling me different things everywhere I look. Do you happen to have experience with this kind of thing?
What classifies as a low-voltage light? My lamps run 60watt bulbs.
Old house, you're probably not going to live in it for the rest of your life, the next owners may use 60w (or larger) in the receptacle, etc etc etc make the lighting up to code and just use the 14 AWG
Better safe than on fire
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Low-voltage usually refers to lighting that runs off a DC supply, 12 or 24 volt. Any standard incandescent or fluorescent bulb you use is going to be 120 volts, regardless of the wattage.
Low-voltage wiring is usually for telecomm, networking, fire, burg, video and access control systems. Electrical sockets, and residential lighting generally doesn't fall into that category. As to why 18 gauge wire isn't a good idea:
18 gauge wire is rated for about 10 A. What you're proposing will be less then 10 A so on the surface it seems like it should work. Except that the circuit breaker for most lights is going to be rated for 15 A. Meaning it's not going to trip until it hits that point. Which is 5 A over what the wiring itself will deal with. If you're around 12 to 14 A for an extended period of time then there is a chance it will catch fire. This is generally seen as a bad thing. This is why the electrical code sets out very narrow guidelines about what wires you use for what circuit breakers and what circuit breakers get used for what situations. Now you may say "Well I'm never going to go above 40 watts, so fuck it." which is the exactly wrong attitude. If the home passes into other hands, they are unlikely to be aware you cut that corner.
So it make it brief, it's a fire hazard. Don't do it. The code exists for a reason and the code isn't written by idiots. Follow it.
It's like chandeliers, the wires with the juice poke out of the ceiling when they are taken down. I am wiring 4 and 5 separate sockets on two chandeliers. The existing wire is ancient brittle stuff with rope casing - somewhat like the stuff shown here but very very old:
e~ The current wires are very small, I can't tell if they were 16 or 18 gauge inside the casing because they are pretty frayed. The guy who was supposed to be doing this job said that they were only supposed to run 40watt bulbs, and the previous tenant was using 60's in the operating sockets.
I'm not an electrician.
But I am an engineer. Listen to this guy. You want to design a system so that the weakest link is what is meant to fail in the case of an accident. In this case, you'd want the circuit breaker to fail before the wire does.
If you are running each socket with its own set of wires to a central point and then joining them to one wire that runs up the chain to the ceiling, your weak point is the wire running up the chain. It will be carrying the load from all 5 (or 4) sockets. If you want to prepare for the worst case (that someone will try to run 200+ watt bulbs in every socket), you could size that final wire to the breaker (14g for a 15 amp circuit and 12g for a 20 amp). But generally, lamps are wired with smaller wire internally all the time.
I talked to my electrical engineer dad and he seemed to think that this was the best plan for my situation. His primary safety concerns were:
1) Don't shock yourself.
2) The 'workbox' in the ceiling which structurally supports the fixture and feeds down the wires is sturdy but old - the wires have the same cloth material casing as the ones I'm replacing on the fixtures (though they are thicker and in much better shape). Point is - probably not up to code. I am not capable or willing to address this, so I'm going to pass that on to my landlord and let him worry about it.
3) The act of joining five wires into one larger wire which I run to the ceiling probably requires a specific technique to do properly.
How to do?
Is there a widget that makes this safe and easy? Is there a picture and a list of Do's and Dont's that I can learn from? How many beers should I have first? Googling for it hasn't helped, and I'd prefer a "this is correct" from someone with some experience before I trust a picture.
Thanks again PA
e~ Man at Lowe's says "just twist them all together in a wire nut".
Well, if the wire nut is somewhere in the wall, a junction box isn't "you'll probably want," it's code. It also has to be accessible.
Yeah that's what I figured, I am obviously not a contractor so I couldn't say for certain.
If he sells his house and someone finds out that it's not up to code he'll probably end up on the hook for the entire house being gutted and redone. Which is fun.
But yeah, junction box if it's not at the fixture. You'll likely still need wire nuts, and the red one is for 3+ wires, so go with what the other poster said. All in all it's like $15, it's worth it to not have to pay $house.
And before anyone says it, yes I am an actual engineer. Not electrical, but smart enough to know it!
Wait a second. Landlord?
Does he know that you're rewiring part of his property without a licensed electrician? Some landlords freak out when you hang up a picture, so I'd be shocked if this guy gave you the go-ahead.
If you do this without his say so, and something goes wrong, he can take you to court. If that house burns down and you survive, you're still completely and totally fucked.
Bad idea. Follow the NEC, do it right the first time. You can save yourself a lot of headaches by doing this.
Make sure you purchase the correct wire type and size. Remember, the ampacity of the wire has to equal or exceed the current rating of the breaker.
Here is a pretty good chart for reference http://www.stateelectric.com/formcalc/ampacity.asp . It is highly unlikely you will be able to buy any #18 or #16 THHN at lowes or home depot.
NEC Article 400, Table 400.4 Lamp cord, voltage 300, AWG 18-16.
400.7 Uses Permitted (2) Wiring of luminaires.
We also have 402.5 Fixture wire, allowable ampacities for 18 AWG, 6 amps.
240.5(b)(2) Fixture wire shall be permitted to be tapped to the branch-circuit conductor of a branch circuit in accordance with the following:
(1) 20-ampere circuits -- 18 AWG, up to 15m of run length
That being said, 18 gauge should be ok for the sockets themselves, but you need to be really careful and tie those wingnuts on properly, because if they get loose, you're going to have some issues (Potentially fiery ones). Also: Running wires in parallel like you're suggesting isn't up to code up in Canada, but then again, I'm a bit confused as to what exactly you're trying to do here.
I'd never try to do something just barely touching the code limits, let alone something beneath them. Electricity is dangerous stuff.
Seems like he's running a length of fire(edit wire, but that is potentially what he's doing) to two different locations. I'm concerned though, because his breaker probably won't trip properly.
Reason I'm asking is because I have a similar situation, I'm basically making a 3 light set up for my balcony, standard E26 sockets with 25W (max 40W) lamps. But I'll be running it out the wall socket rather than ceiling junction box. All the light plug/socket/wire combinations I've found at hardware stores use 18AWG, even the ones I've found at IKEA... so I don't really see the many "words of caution" on this matter. Light bulbs don't take juice like powered tools, low amperage won't heat wires, 1100 watt capacity per hour vs a max of 120W/hr and specifically considering the setup will not always be on. As @Mushiwulf said, it's pretty standard and whoever said parallel connections is not code, it is my understanding that 3+ light fixtures are done this way, not in series certainly.
Would be interesting to hear from OP, I'm fairly certain he had no issues whatsoever.
OP probably hasn't had any issues - most people won't.
The amount of money and work you save is negligible, use 14 gauge.
If you don't know what's code, find out and follow it.
After the rewiring I've had many far fewer bulbs burning out too - but my place is old and anything would have been an improvement.
I was trying to accommodate the space in an original antique fixture and the thinner wires worked out for my needs - but still, I'd have to agree with @zagdrob that you shouldn't do anything less than standard if you're starting a project and have the option to just be smart.
Where you can get into trouble is not just if someone puts 200W bulbs in every socket, but if a hot wire breaks and shorts back to ground. The current will rapidly rise until the breaker trips. Your wire had better handle that current beyond the breaker's trip point.
I would throw in a curveball of the wire temperature rating as well. I recently picked up a waterproof lamp socket for a project. There are surprisingly 14AWG wires built in, instead of teh usual 18 AWG. However, the rating on those wires is TW, which translates to 60 degrees C and maximum 20A current. Looking at 18AWG wire in some lamps, it is all rated TEW for 105 degrees C, or 18-20A max current. That should be enough to trip a 15A breaker before the wire catches fire.
References:
IEWC Suggested Ampacities
Cooner Wire Amp Chart
ee.nmt.edu/~wedeward/EE382/SP02/current_capacity.pdf
Thanks,
--H