Planning Circuit

I'm planning the electrical circuit for my new bathroom addition. I'm learning fast, but I don't know enough about planning circuit size & load. Are there any good websites that can tell me things like how many fixtures/outlets I can have on a circuit and/or what circuit size to use? I've actually already drawn my wiring plan, but I'm not sure of what size circuit to use. Thanks in advance...

 

Nobody should attempt a home wiring project without a good book or two. Such books are inexpensive at home centers, or free at public libraries under the search term "home wiring". Some may disagree, but most books are organized much better for learning how to do a project than most web sites. Web sites such as this and many others are great for researching specific questions that may arise in the course of the project.

Bathrooms and kitchens are the two most regulated rooms in the house, as well they should be, since water is involved.

The simplest way to wire a bathroom is to devote one 20-amp circuit to it (you may not use a 15-amp circuit for the bathroom receptacle). Put in exactly one GFCI-protected receptacle per sink (no MORE than 36" from the edge of the sink), and put the lighting and exhaust fan on this circuit too. Do not put anything outside the bathroom on this circuit. Keep all outlets out of the shower/tub enclosure, and only put a light in the tub enclosure if the light is specifically approved for that use (but I recommend against it anyway). This advice is not the only code-legal way to do it, but it is the simplest way and the way I would recommend.

If you plan a significant heater too, you may need another circuit for that.

Any questions?

 

I asked a similar question in the "Bathroom Circuits" thread I started before I read this one. Mr. Nelson answered my question, but I do have a follow-up:

- Would it be within code to do the GFCI recept and exhaust fan as you said, but put the lighting on another circuit with other lighting in the house?
- If yes, would that be safe and/or would you recommend it?

The reason I'm considering that, is if there were a problem with the exhaust fan and/or receptacle, it would be nice to still have light in there to see to work.

If it would be safer to have the light on the same, then I would rather be safe than be convenienced.

 

Moonpie, your way is fine too. I neither recommend for it or against it.

 

Many people reccommend your method of light and recepticle on different circuit just for the reason you stated. The lights stay on of you trip the gfci or the cb.

 

Thanks for the replies. I didn't mention in my earlier post that I have already purchased TWO books. They do a pretty good job, but I was still hazy about circuit size. I assure you that I do LOTS of homework before I undertake any project, especially electrical. I have built my entire bathroom addition on my own, and I've learned how to do everything along the way, including framing, plumbing, and HVAC.

Thanks a bunch for the replies... once I get a final wiring plan drawn up, I'll probably post it here for you all to critique. Of course, everything will be inspected and to code. Thanks....

Brian