Let me belabor the 12 gauge -> 14 guage discussion

[pashag]

Hi,

I recently asked whether it's OK an a 20amp dedicated circuit intended for a heater/fan/n.light/light combination to run 14 gauge wire from the switch to the fixture, except for the heater part. And of course, the answer was "no" because you are not suppose to use 14 guage wire on a 20 amp circuit.

But the wire in the fixture is 14 gauge! (Except for the heater part. There are three 14 gauge and one 12 gauge pairs inside the fixture.) How is that not breaking the code on the part of the manufacturer?

Thanks,

Aaron

[Calab]

Because you won't be adding more circuits inside the fixture!

With 14 gauge in your wiring (not inside a fixture) there is the chance that someone will later add more 20 amp circuits because they see the 12 guage wire and don't realize that there is any 14 gauge in your circuit.

[pashag]

Yes, but I was proposing is connecting the switch to the fixture (a 4' run!) with 14 gauge wire. That would essentially make it an extension of the fixture's own 14 guage. Why is that not legitimate. If the answer is that "the code tries to be overprotective", I'll accept that. But I want to make sense out of it.

Thanks.

Aaron

[Calab]

Because the fixture will be at a junction box... Wiring could get added from this box to a new circuit.

[Aaron Fude]

The fixture's junction box is _inside_ the fixture. Are you suggesting that someone might add a new circiut downstream from the fixture? That would be far fetched.

[RBM]

The wiring in the fixture probably wasn't even #14, as the fixture manufacturers use wires sizes only large enough for the loads on them, and don't have a minimum trade size of #14. They are also governed by a different code than the building wiring

[hallerb]

I do admit its wierd, a great example you can plug a 4 0r even 16 gauge extension cord in a 20 amp outlet..........

and probbly have a nice fire........

have customers who try that:(

one in a mall put a groundung adapter in line oin a 16 gauge lamp cord extension cord and plugged in their 18 amp seal press, appearance before function or safety.

this in a mall.

I warned them, documented the hazard on my service slip and left.

6 months later they called again, having new problem.

they had responded to my safety issuem by stapling the lamp cord to a carpeted wall:(

I fixed the machine left it heating, and went shopping for a air conditioner extension cord which I gave them FREE.

came back removed light cord cut into pieces and tossed in trash.

the manager was MAD, We cant pay for the new cord.........

I told them its FREE, my contribution so the mall doesnt burn down or someone get killed, espically a customer..... they could walk by the area.

hey the paperwork for the fire reports will cost more than the extension cord

[ds549]

i use a 12 guage , but have heard that 10 guage and 14 guage shotguns used to be popular , but not anymore.

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[Jim Redelfs]

Only one with full access to the latest National Electric Code would be qualified to address this, but I think you are OK/right.

I recall (Kitchen?) where a 15-amp-rated device or wire is allowed for short-run purposes with 20-amp overcurrent protection.

It has been YEARS since I bought a current copy of the code. Perhaps it's time again, but it's too much money for it every time I look.

[bud--]

Nope. Caleb and RBM are right.

15A wire - no.

A 15A duplex receptacle is rated for 20A total from both halves.

An old NEC probably has the same rules on this. The NEC is available online.

[Wayne Whitney]

The basic answer is this: the manufacturer of the appliance (or fixture) can make the reasonable assumption that the wiring internal to that appliance will only ever carry the load of the appliance. So it can size the wiring based on what the appliance itself will draw. If it is critical that the appliance wiring not be overloaded, the appliance can contain a fuse sized appropriately.

The wiring within your house, however, may get reconfigured or may carry additional loads beyond the single appliance. So it is subject to the usual rules of the NEC, like minimum 12 gauge wire for a 20 amp circuit.

Yours, Wayne

[John Gilmer]

1) that's the manufacturer's problem, not yours. If it's UL approved then that's "gud enuf." There is little question that a hard fault across #14 wire will trip a 20 amp breaker so there really isn't much of a safety concern. Light fixures often have #16 wire inside them. Most extension cords are only #16. 2) In your PARTICULAR case, if you can you might want to run separate circuits for the heater and for the lights. You can flip a coin to decide whether to put the fan on the "light" side or the "heater" side. If the heater is 10 amps or so, you can power it from #14 and #14 is already OK for the lights and a small fan. If you use separate feeds in the same fixture you have to make sure you connect the right neutral wire to the right cable. Of course, the breaker for #14 circuits must be only 15 amps. ** Posted from **

[salty]

Please note that the filiment wire in a perfectly safe and legal 100 watt incandescent light bulb is no where near 14 gauge!

[dpb]

[e-mail] wrote: ...

Also note the temperature it runs at would do serious damage to a distribution wire...

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[AZ Nomad]

Irrelevent. 100W incadecent lights aren't used to carry current to 2000W loads.

[salty]

I guess you aren't following this thread very carefully. The poster was wondering why the wiring inside a fixture did not have to be as large as the circuit TO the fixture. My point is that the code specifies wire gauge in the supply circuit, not inside devices.

Completely relevant.

[Jim Redelfs]

If I recall correctly, NFPA charges A LOT to access the NEC on-line.

I'd rather pay the difference, whatever it might be, and get a hard copy. Still, that, also, is too expensive considering I have no PROFESSIONAL need to purchase such a reference.

[Calab]

Actually, the OP wants to know why he can't use 14 gauge wiring on a 20 amp circuit.

[Seth Goodman]

It's available on-line for *free*.

2008 NEC: 2005 NEC:

[David Nebenzahl]

On 6/3/2008 8:26 PM Seth Goodman spake thus:

Sure, if you don't mind the ridiculous restrictions of "RealRead". (In all fairness, it's probably the only reasonable choice they had to publish it online; if they simply made PDFs available, I'm sure that would cut significantly into their hardcopy sales.)