Upgrading from 15 to 20 amp circuits?

[Bantik]

My wife and I bought a 1933 house in December. Now that it's summer and we're running the window air conditioning units, we're having a lot of trouble with tripping the circuit breakers. We can't have the stereo or TV on at the same time as the air conditioner, for example.

I'm currently in the process of pulling out all of the old cloth-and-varnish wire (at least there's conduit already!) and running new 14 gauge wiring throughout. My question is, what's involved in upgrading circuits from 15 amp to 20 amps? And since I'm pulling wire anyway, should I be using 12 guage in anticipation of the upgrade?

Thanks,
Corey

[Snoonyb]

Use #12 stranded throughout, and a single #14 as the ground.

[HayZee518]

If you have conduit, run #12 thhn/thwn inside. Any surface or hidden wire use #12 romex with ground. This way you can always downsize the breaker to a 15 amp type or run a 20 amp circuit and not have to worry about nuisance tripping. But should you need a 30 amp breaker make sure the wires are #10 gauge.
An air conditioner should be on it's own dedicated circuit, I might add.

[Bantik]

Snooonyb: Is there any particular reason to choose solid vs stranded?

And to HayZee: If I split the AC onto its own 20 amp cicruit, is it okay to run 12 gauge wire for the new circuit through the existing conduit side-by-side with the 14 gauge serving the old circuit? Is there a color-coding-convention to follow in that case, so that no one will confuse the two circuits?

And if I'm understanding this correctly, 12 gauge wire is fine for 15 amp circuits as well as 20 amp circuits. Right?

Thanks again,
Corey

[LazyPup]

When running multiple circuits of single conductor wires in conduit a trained eye can easily spot the different size of wires however when you have multiple circuits using the same size wire it can become confusing. While color coding is definititely an option often you simply do not have enough colors of wire to make that practical. The simple solution is to use "Numbered Wire Markers". Numbered wire markers are small strips of tape about 1/8" wide and precut to just fit around the wire with a number preprinted on the tape. When the tape is wrapped around the end of the wire you have a visible number to sort out the circuits. The wire markers come in booklets or a plastic dispenser magazine with numbers from 0 to 9. You can then use a combination of number tapes to create any number you desire.

Normally when pulling multiple wires you put a matching number on each end of the wire before pulling it so you can quickly identify both ends of the wire after it is pulled through the conduit. The wire markers are intended for permanent use and they also make trouble shooting a circuit much easier in future.

You can usually find numbered wire markers in the home supply stores in the section with the electrical tools or you can get them at any Electrical Supply House.

[Snoonyb]

Originally Posted by Bantik

Snooonyb: Is there any particular reason to choose solid vs stranded?

Stranded is more expensive and more flexible and because I have a balance of commercial and residential clients, I use the stranded predominently. It is far simpler to pull additional circuits with flexible wire.

[/quote]And to HayZee: If I split the AC onto its own 20 amp cicruit, is it okay to run 12 gauge wire for the new circuit through the existing conduit side-by-side with the 14 gauge serving the old circuit?[/quote]

Yes, and they can share the neutral.
Find this and it will explian a lot: splitting circuits and sharing neutral, bottom of page 2 or top of 3.

[/quote]Is there a color-coding-convention to follow in that case, so that no one will confuse the two circuits?[/quote]

Generaly black,red and blue for the hots.

[/quote]And if I'm understanding this correctly, 12 gauge wire is fine for 15 amp circuits as well as 20 amp circuits. Right?[/quote]

12ga is rated for 20amp. up to 100 feet from the breaker.