[rick1040]

Hello, I have bought a house that was gutted do to a fire, the house was built in 1967 (Texas) all of the wiring in the house is aluminum, since 1/3 of the wiring was damaged in the fire I won't to replace all the wiring with copper wire. I will run #15 wire for all lights, #20 wire for outlets (living, hall,4-bedrooms). How do I calculate how many lights to a #15 and how many outlets to #20. I have been told 7 to 8 outlets on #20 and 10 to 12 lights on #15. In the kitchen I was planning on running #20 to refrigerator and one outlet, #20 to stove (gas) and microwave, #20 to dishwasher, garbage disposer and 3-counter top outlets.
Thank you in advance for all your insight.

[Stratmando]

I take it you mean 12 gauge wire which handles 20 amps, and 14 gauge wire which will handle 15 amps.
The Kitchen recepticles are 2 to a circuit and need to be GFI protected. If money is not real tight, I wouldn't use #14 gauge wire. #12 for everything, except for the large loads, A/C Range Dryer Etc.

[rick1040]

Tks
For living room and bedrooms what is a good rule of thumb for how many recepticles to one circuit?

[donf]

In residential wiring, there is no limit on the allowable receptacles.

However common sense does limit what you install.

For example, a 15 amp / 120 VAC circuit will allow up to 1800 Watts.

If for example you wanted to supply power for a 1700 Watt device you would be fine using this circuit as a independent or dedicated circuit.

However, if you are planning on supplying more than one outlet you are limited to 80% of the 1800 Watts or 1800 X .8 = 1440 Watts.

So you would figure out how many outlets you want to use and the number of watts used per outlet to get a circuit total.

For example, 1400 / 60 (sixty watt lamps) = 24. If however you wanted to use 150 watt lamps, then it would be 10.

The math applies to a 20 amp circuit.

With respect to the kitchen, there must be two 20 amp branch circuits to supply the kitchen counter top receptacles and both must have GFCI protection.

There is a very good book on Residential Wiring by Ray Mullin that shows you how to do the worked based on the 2008 NEC. I do not know if he has released a 2011 book yet.