12/2 w/grd. circuit with a 14/2 w/grd. branch

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hardworker

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I am working in a single family residence that has a circuit of 12/2 w/grd. that has a 12ft. branch on the end of this circuit that is served by 14/2 w/grd. The 12/2 feeds 10 100wt. light bulbs in another part of the house and the 14/2 branch feeds 8 100 wt. light bulbs over a large vanity. I would replace the 14/2, but I would have to tear-out half the bathroom to get at it in the wall. What does code say about the breaker to serve this circuit? 20amp or 15 amp. ? Please comment. Any other code problems here?
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

The scariest part about this situation is that the potential is there for this circuit breaker to be replaced by a 20A even with the right intentions in mind. For example, if the circuit breaker was to fail at some future time and need replacing the homeowner, not knowing that some of the wire of the circuit is only 14ga., could replace the breaker with a 20A based on the fact that he/she sees 12ga. wire terminated. Are there provisions to provide proper warning for such a situation?

Bob
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

If I placed a notation warning on the service panel, would that pass code?
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

The warning should be "if you don't know what you are doing, stay out of the panel." Anyone that blindly changes a 15A CB to 20A shouldn't be doing the work. There are so many ways the homeowner can screw up the wiring a warning could never cover them all.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

The NEC has no requirement for a warning label in this application. A conductor has to be protected at is ampacity per 240.4.
However a warning label is a good idea, I would put it on the conductor by the ckt breaker, use a write on wire label. Take a picture and keep in it your file. You could also put a label inside the panel door as well, the one on the wire is less likely to be removed.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

I see this sort of thing all the time...

I'd downgrade it to a 15A breaker (if its permissible for that branch to be 15A) and make a note on the panel cover stating that particular breaker must remain 15A because #14 is present downstream.

You might suggest to the homeowner that using some CF lamps will go a long way towards reducing the load on that branch.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

The 14/2 in this case does not meet any of the requirements in 210.19(A)(4) exception 1 or 410.67(C) for tap conductors, so it has to be protected by a 15 ampere OCPD. Installing a 15 amp breaker to this circuit with 18, 100 watt bulbs (1800 watts) would create another violation. Lighting is a continuous load - a 15 amp, 120v circuit breaker under continuous load is suppose to carry 1440 watts maximum.
You can use smaller wattage bulbs.

Pierre
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Are there any legal branch circuit taps, besides the exception for the microwave off of the range? I think just about every tap must be a feeder tap.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Ryan

Are you saying that it?s legal to tap off a 50 amp range circuit to feed a standard microwave? If so I disagree.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Ryan the only time a microwave can be taped off a range is if it is listed for hard wiring. if it requires a receptacle outlet then NO.

Look at 210.19(A)(4)(c)
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

when I find a wiring situation like you mentioned ie. 12 and 14 mixed. I cut the feeder in the panel close to the box. I then connect a piece of 14 wire to replace the 12, all conductors. This way it is a #14 wire. If the breaker gets replaced then it still is a #14 and should be used with a 15 amp breaker. If it is overloaded then you have to make changes.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Ryan

Standard microwaves come with 16-3 or 14-3 flexible cords and a 15 amp cap. They are only listed for connection to a 15 or 20 amp circuit. 240.5 would also prohibit connecting them to a circuit larger than 20 amps.

The newer light bake ovens such as the GE Advantium are hard wired appliances and require a 30 amp 120/240V circuit. The instruction allow them to share a 50 amp circuit with another single oven.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Thanks for all the input. I have a theoretical question on this subject. Why is it permissible by code to wire lights with 12ga., use a 20amp breaker, when everybody knows the wire within the light fixtures are probably 20ga. stranded or lighter? How does this make sense?
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

So, if our microwave oven had a 20 ampere capacity cord, it could be connected via a 20 amp receptacle and #12 copper tap conductors from the 40 or 50 amp range circuit?
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Hardworker,
Check out Table 402.5 and 240.5(A)(2). The wire in fixtures isn't regular building wire, but rather fixture wire (of all things). Maybe that's why fixtures are now called luminaires?
Anyway, NEC 240.5(A)(2) allows fixture wire of #18 AWG up to 50 feet long to be connected to a 20 amp branch circuit. But, 240.10 requires supplementary protection for the fixture wires, limited by Table 402.5, which limits #18 to 6 amps.
The fixture should have a OL thingie in series incorporated into the fixture somewhere.
Ballasts have a cutout switch. Regular incadenscent luminaires have a sticker that limits the wattage size of the lamp. (If you overlamp the fixture how do they find out?) But, a 100 watt bulb draws less than one amp. How big do light bulbs go? I've seen 200 watt, anything larger requires a mogul socket. Using #18 fixture wire, we are allowed to draw 6 amps.
Maybe this is why those receptacle that screw-in the light socket adapters are not a good idea?
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Early - I believe 210.19(A)(4) exception 1(c) prohibits receptacles from being supplied from a tap.

[ February 18, 2004, 12:05 PM: Message edited by: dana1028 ]
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

210.19(A)(4) Other Loads does, but 210.19(A)(3) Household Ranges and Cooking Appliances doesn't.
The handbook lists four conditions:
1) The taps are not longer than neccessary
2) The taps are properly spliced
3) The junction box is adjacent to each unit
4) The taps are of sufficient size for the load.
I don't see any prohibition on receptacles or a requirement for hard wiring.
The tap article, 240.21, deals with feeder taps only, as it refers the reader to 210.19 for branch circuit taps.
 
Re: 12/2 w/grd. circuit with a 14/2 w/grd. branch

Early - the Handbook illustrates the use of taps to feed countertop cook top units, ovens, etc....

The purpose of these taps are to supply the related (hardwired) cooking unit/range/oven appliances...

I do not see this as allowing a tap to create a receptacle for countertop portable appliances.
 
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