re: need help

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TexasMaster

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Lubbock Texas
re: need help

Just saw a post that reminds me of something I've always wanted opinions on from people in other areas for years now. The city I work out of and surrounding communities have always allowed us to use 14gage on a 20amp ckt where it's just a swt-leg, swt-loop, or just connecting lighting. In residential only. Is anyone else doing this or know any loop-hole that allows this?
 
It's not an NEC rule as the NEC specifically prohibits it. If your locality allows it, I would still not wire it that way. The NEC is a minimum standard, and local amendments should be more stringent, not less.
 
Often discussed here. It was allowed in many areas for so long it still appears as "normal" to some old-timers. I beieve it has been shown here to have never been "legal", but was simply accepted.
A left-over from the days when every room had one incadescent lamp for illumination, I guess
 
I could see adding an exception to permit this for the switch leg for a single residential occupancy light fixture. The short circuit and ground fault time current curves for 15 and 20 amp breakers are almost identical and it would be unlikely that the fixture would have a load greater than 12 amps. The code already permits up to 50' of #18 fixture wire to be protected by a 20 amp OCPD. 240.5(B)(2)
 
The short circuit and ground fault time current curves for 15 and 20 amp breakers are almost identical and it would be unlikely that the fixture would have a load greater than 12 amps.
But, could #14 heat up to dangerous temperatures at a current that wouldn't trip a 20a breaker (but would trip a 15a)?
 
But, could #14 heat up to dangerous temperatures at a current that wouldn't trip a 20a breaker (but would trip a 15a)?
Larry,
If this was limited to a single fixture, it would be almost impossible to overload it from the fixtute load (I haven't seen a residential fixture that you could install more than 1440 watts of load), and excessive heat from a poor connection is not detected by a standard breaker.
Also the #14 won't exceed 60?C with a 20 amp load per Table 310.16.

I don't expect the code making panel would accept a proposal like this, but I don't see a safety issue with it...remember they already permit the use of up to 50' of #18 fixture wire on a 20 amp OCPD. The theory that permits that is the same as I am suggesting for the #14. The load is limited by the fixture and the short circuit and ground fault protection is provided by branch circuit OCPD.
 
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