Running light off of outlet and wire guage questions

Old 04-17-01, 10:22 PM
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I've already done this, so let me know if I screwed up. If I tap into an outlet that is a 15 amp on a 20 amp circuit with 12/2 wire do I need to run 12/2 to the switch and on to the light fixture? What I have right now is this: 20 amp breaker, 12/2 wire run to 15 amp wall outlet (GFCI), 14/2 wire run to wall switch, and then 14/2 run to light fixture.

Old 04-18-01, 04:07 AM
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If the outlet is a "brand name" and you didn't use the push in connectors, you should be OK.
Change the 14/2 to 12/2. Don't "mix" wire in a circuit, and 14 ga is inadequate in a 20 amp circuit.
Old 04-18-01, 05:58 AM
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Looks like I got some bad information. It seemed logical to me since the lights would not be pulling anywhere near 20 amps. I know the ground wires do not count toward the total wires allowed in a box. I read somewhere to count the switches as one wire, is this correct? Also, I can wire the lights and outlets on the same circuit in a bathroom can't I? thanks.

[Edited by johnjk on 04-18-01 at 09:08]
Old 04-18-01, 11:14 AM
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Yes, you got very bad information. Do not accept information from that source again. Properly functioning lights won't draw 20 amps. Improperly functioning lights could burn your house down if you don't replace that 14-gauge wire.

Whether or not you can wire the lights and outlets on the same bathroom circuit depends on what else is on that circuit. You tell us and we'll tell you.

Cable fill guidelines are kind of complex and confusing. There is a lot of information you need in order to "count". I suggest you consult a book.
Old 04-19-01, 05:52 PM
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The NEC forbids anything not in that bathroom to be on a circuit that supplies the GFI receptacle. No you can not take power out of a bath room receptacle circuit to serve outside that bath room.

All insulated conductors are counted in box fill calculations except bare grounding conductors. Bare grounding conductors as a total in that box are counted as only one conductor. Devices [switches and receptalces] are counted as to conductors. 12 ga is calculated at 2.25 cu in per current carrying conductors and 14 ga is calculated at 2 cu. in. per conductor.

John is right you should not mix wire sizes in the same circuit regardless whether it is a switch leg for a light or not. Now the NEC does allow this mixing of conductors but I advise that mixing to be done by qualified electricians only. If you opt to mix the wire sizes of a certain circuit then you must size your breaker or fuse that protects that circuit by the smallest conductor in that circuit. If you leave that 14 ga in that circuit reduce the breaker size to 15 amp rated.

Hope this helps

Old 04-20-01, 09:40 PM
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more help needed :-)

I posted a big long reply and lost it somewhere, so here I go again.

First of all, I took all the 14 ga. wire out and put in 12 ga.

I've got a 5' x 4' closet off this bathroom. I ran a light for it off my bathroom gfci. I guess from what you say I cannot do this?

The reason I was asking about the box capacity is this:

I've got a 2 gang switch box, I can't remeber the cu. in., but it's rated for 15 #12 wires, so based on the 2.25 factor it should be around 34-35 cu. in. I have the following in it:

1 12/3 wire
4 12/2 wires
1 3 position switch for my bathroom fan/heater/light
1 switch for my vanity light

It seems I may be 1 conductor over the max. Is that what you all think. Would two switches count as 5 or 4 cu. in.?

Also, I made a slight mistake when hanging drywall and knicked 2 of my wires in the box with my dremel tool. I cut the wires off to a point where they were about .5 inch from reaching the face of the box and installed pigtails. I assume this would not affect my wire count?


[Edited by johnjk on 04-21-01 at 12:49]
Old 04-23-01, 08:36 PM
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Your close the conductor count would be 16 and your box copacity is 15. I wouln't flag a count that close in my jurisdiction. No the pigtails you added neither enter the box nor leave the box and would not be counted.

Now as for a light in a clothes closet, if surface mounted incandescent lighting, you must maintain 24" from the back and side walls and also maintain 12" from the front of any storage shelving in that closet. The incandescent lighting must also be with a closed lens.

Same goes for recessed or flourescent only the measurements for clearance must be 18" from back and side wall and 6" from any shelving.

Good Luck

Old 05-02-01, 01:06 AM
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Since my closet is going to be 60" x 42" can you give me some suggestions on what kind of light to use with a suspended ceiling? It's obvious I'm not going to get 24" clearance on the sides. Also, what would be the best way to mount it to a suspended ceiling? Thanks.

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