Electrical wiring

[LRod]

Actually, I'd be surprised if 10/2 was used in 120V circuits at all.

[Patriarch]

Puckdropper wrote in news:46c16738$0$97233$ [e-mail]:

An entirely different kettle of fish. The wire you used is part of the standard for both speeds, and maybe others, and works pretty easily for the setup you describe.

Which is pretty much exactly what was discussed back in the early to mid-90's when all of this started to come together...

Patriarch, who did the same thing, really...

[Doug Miller]

There would be a few rare cases, such as

- very long run on a 20A circuit, where voltage drop is a legitimate concern

- 30A circuit supplying, for example, fixed space heating equipment but I'm sure that its most common use, by far, is in 240V circuits.

[Roy Smith]

Right. It makes dandy speaker wire.

[Wes Stewart]

On Tue, 14 Aug 2007 15:48:08 +0000, LRod wrote: [snip] | |Actually, I'd be surprised if 10/2 was used in 120V circuits at all.

Very common in the recreational vehicle world. Let me rephrase...120V,

30A circuits are very common in the RV world. (What wire size they use is unknown) Most RV parks provide 30A hookups; with some supplying 50A circuits for "big rigs", those with dual A/C, washer/driers, etc.

[jimbrown]

I want to thank all the posters for the information. I have read everyone post and appreciate the time and effort in answering the question. I meet with the electrician next week in wiring the shop.

Thank you.

Jim

[Mike M]

#12 thhn cu wire is actually rated for about 35 amps. The restriction to 20 amps is mainly based on the rating of the terminal on the CB. You may use the higher ampacity ratings before taking your derating but still can't have over a 20 amp breaker.

Mike M

[Doug Miller]

30A, actually.

That's part of it, but not the only reason. 10, 12, and 14 gauge wires are the sizes most commonly used in residential circuits. The allowable overcurrent protection is set by the Code at a value significantly under the actual ampacity of the wires to reduce the risk of fire from overloading a circuit.

Which means that the higher ampacity ratings are, for all practical purposes, irrelevant. :-)

[Mike M]

Shows how bad my memory is getting.

This is true for residential work generally, but in commercial work where you might be derating for continuous load, number of conductors in pipe, as well as ambient temperature it can make a difference.

Mike M

[Jim Brown]

since my first posting a few weeks ago I have contacted an electrician who than decided not to show up. I than decided to do the wiring myself and am happy to say that it is complete and inspection passed.

I would like to thank all posters who threw their 2 cents in.

Jim

[Jim Brown]

Just a quick note about the progress of my garage. Since the first post I have contacted an electrician, who decided not to show up. I thus decided to do the wiring myselft. With the advice from this post the wiring is finished and passed inspection. I want to thank all who have thrown their 2 cents in helped me accomplish this part of my project.

Thank you.

Jim