Im wiring a custom home, and have some homeruns that were so long i up-sized the wire for voltage drop. Now that i have a 10-3 in my 2 gang nonmetallic box, i need to pig-tail the wire down so it will fit on my devices, which are rated only for 12 awg. I came across NEC 2002 table 210.24 and saw that i can tap #14's off of the 10's. Am i in the correct Table? if so, how long can those pigtails be? If not, where do i look?

It is not a tap as the breaker will be (better be) a 15 amp.

Most receptacles I use will accept 10 AWGs anyway.

Tap with 12 or limit breakers to 15 amp.

I had a situation where # 2 had to be used for voltage drop to a duplex receptacle. Then pigtailed to #12 for the device and at the breaker.
Alan--

We need to be careful how we use the word tap. Many of us use the word 'Tap' in ways that the NEC does not.

Here is the NEC definition of tap for Article 240


Bob

Clem, if you have home runs long enough for voltage drop to be a real concern, you should look into using sub-panels. This increases the performance of the system, as well as possibly even reducing labor and materials costs.

We're wiring a 7500+ sq.ft. house, and we used a pair of sub-panels, one for each main panel. This is because we used the two 200-amp panels to divide the standby-generator loads from the non-generator loads; and only needed one 200-amp ATS.

socalclem,

You're hunting for table 210.24....

Also study 240.5 particularly 240.5(2)

Also study 210.19 (A)(3) exceptions #1,#2

Also study 210.19 (A)(4) exception #1 (c)

These tap conductors are limited to 18 inches.

The Code permits #14 protected by 20A breakers for this application.

I'd think the simplest thing would be to use receptacles that will take #10 wire. Many or all of the Hubbells will take #10, and I believe some or all of the Levitons will, as well. I haven't looked at the specs on other brands; I suspect a lot of them will take #10, too.

[This message has been edited by SolarPowered (edited 12-07-2005).]

This section applies to your situation: "210.19(A)(2) Multioutlet Branch Circuits. Conductors of branch circuits supplying more than one receptacle for cord-and-plug-connected portable loads shall have an ampacity of not less than the rating of the branch circuit."

This section does not apply, because you are using receptacles: "210.19(A)(4)(c) Individual outlets, other than receptacle outlets, with taps not over 450 mm (18 in.) long."

You have to have minimum #12 copper for a 20 amp branch circuit, including the pigtails to receptacles, and even if you use 15 amp receptacles. The length of the pigtails is not stated. Sufficient to do the job, but not so long that you can't stuff all the wires back into the box.

Thanks for all of the information, i was hoping i could find a place where i could pig-tail Down in size say on a 12-2 to 14, so i could stab all my receptacles instead of wrapping them. I guess it was too good to be true.

Ok, another situation: with copper prices as high as they are, using scrap pieces of wire is becoming more common. What if i wanted to use an 8-2 to supply say a laundry circuit instead of 12-2, now what am i suppose to do with #8 on a receptacle?

I have done this more than once to save on wire, there has to be a time when we can be able to "pigtail down" to accomodate situations like these.

Why backstab, Did you not bid the job high enough to make a fair profit? I don't mean to come off rude but it has been my experience and many others that backstabbing is going to cause problems in the fututre.

Do you really want others in the future (if someone else ends up doing their electrical work) explaining to the homeowner that the reason they are paying a service call and having problems is that the electrician who wired the house tried to save time by backstabbing the devices?

Yes, you certainly can "pigtail down" to fit a device; just remember that the breaker must be sized to protect the pigtail. I wouldn't use stab-wiring in any case.

You can run #8 to a recepacle, and then use a smaller pigtail on the terminals, again as long as the breaker is rated for the smallest conductor it protects.

You'd have to do that anyway, to protect whatever gets plugged into a 15 amp outlet. Typically a table lamp with #18 zip cord.

There is one very specific difference between the pigtail to a receptacle and the cord of a lamp you plug in. You are only providing short circuit protection to the lamp cord, the lamp socket itself is defacto overload protection. In the case of the receptacle you have to provide overlaod protection too, since you have no control over what is going to get plugged in so 240.4(D) rules.
I suppose someone can still put a plug adapter in a lamp and plug in the 1440W heater but we can't save everyone.

The way I see it, you only increased the wire size for voltage drop across the run and the device isn't rated for more than 15 amps anyway, so you are absolutely going to put a 15 amp breaker in the panel.
What's the problem?
The #14 pigtail is good for the maximum the breaker will allow. no problem right?