How many circuits do I need?

trekkiejt

Howdy, I am going to finish my basement and am unsure of the wiring situation. Right now, everything down there is running on one circuit (except the dryer) as well as the outside outlet and the dishwasher upstairs. This includes the washing machine, dehumidifier, gas furnace, A/C, and nine lights. I plan on putting in a bathroom, finish the laundry area, and add two bedrooms plus a large storage closet (plus various little closets, pantry). How should I (re)wire this? I'd like to put 3 outlets in each bedroom, two in the laundry, and two in the bathroom plus a couple extra lights. How many circuits do I need and what should be on them? I have room on my main panel (100 A) to add six breakers. The existing wiring is all original to 1957 without ground but the plastic insulation on the individual wires (under the paper and fabric wrap) is still pliable and peels off the copper almost like it's new.

AllanJ

One 20 amp circuit for laundry area receptacles only (mandatory), one 20 amp circuit for bathroom only (mandatory), two 20 amp circuits for all other receptacles and lights, one circuit for furnace, as a reasonable bare minimum. Starting with the single existing basement circuit and six empty slots you have two slots remaining for air conditioners and will need both for one AC circuit for one and possibley two 240 volt AC units.

Depending on whether your panel will accept them in terms of fit and total number of breaker handles, you can use a few tandem breakers (single wide double breakers) so the dishwasher and receptacles in unfinished parts of the basement for the dehumidifier don't have to share the two general purpose basement circuits and/or furnace circuit. Also nothing keeps you from plugging the dehumidifier into the laundry circuit if you don't trip that breaker.

You will need to do a load calculation (refer to National Electric Code) for the entire house for a project this big. It is possible you may need to upgrade the 100 amp service to 150 amps or 200 amps.

You will not need to replace all the upstairs original wiring with grounded cables in order to do this project.

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trekkiejt

Very detailed and exact, thank you. This is exactly what I needed. Would it be better to just install a subpanel in the basement?

ddawg16

Unless you see the need for additional ckts at a later date...I personally don't think it's worth the effort...unless your a pretty good distance from you main load center.....or, if your running out of spaces in your main load center.

If the dryer is electric....you will need a 240 outlet for it in addition to the dedicated 120vac outlet for the washer.

On a personal note....I would run a second 20a....put it near the washer/dryer for use by an iron....

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trekkiejt

The main panel is almost closer to the basement than the first floor. It's in the stairwell on the wall opposite the door at the bottom above the lower stairs. The dryer already has a dedicated 240. Why a separate circuit for an iron? I only use one to put patches on clothing and I don't think my wife has ever used the one we have.

AllanJ

In addition to the required dedicated 20 amp circuit, a laundry area can have receptacles on other circuits shared with other rooms.

It is your choice whether to add receptacles on a different circuit depending on if you trip the breaker while doing ironing while the washing machine is on, which is not that likely with a 20 amp circuit.

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The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.