To Whom it May Concern:

My name is Brian and I'm looking at finishing out my basement and currently have a 150 Amp service running into the house and was wondering if my current service would be enough or do I need to upgrade to a 200 Amp service. Current living space is 1,750 sq. ft and when the basement is finished, should have a total of 3,200 sq. ft. I am NOT planning on adding any additional heat/air conditioning to the basement. Currently I have the following major appliances:

Dryer - currently on a 30 amp dual breaker
A/C - currently on a 30 amp dual breaker
Dish washer - currently on a 20 amp breaker
Washer - currently on a 20 amp breaker
Furnace - currently on a 15 amp breaker
Garbage Disposal - currently on a 15 amp breaker

The current panel houses the following breakers:
2 - 30 Amp Dual Breakers
10 - 20 Amp Breakers
9 - 15 Amp Breakers

The finished basement will consist of a bathroom, large playroom, bedroom, and work shop. Workshop will not have any heavy equipment, only standard circular saw, 12" miter saw, and such.

On a second note, do GFCI outlets need to run on a 12/2 homerun or can they be on a 14/2?

Sincerely,

Brian

Whether you add any additional HVAC loads or not, 3200 sq. ft. is one heck of a lot of living space for 150A. You should do some load calculations, but I'm sure you would be much happier with a 200A service. It will allow for some additional loads in the future if you end up needing them. And I'm here to tell you, you are going to want 3 circuits alone to your workshop. One for lighting, and two 20A circuits for equipment. I'm telling you... you'll be sorry if you don't plan for at least that.

GFCI circuits can be run with either size wire. The wire size dictates the max allowed current protection. #12 for 20A, #14 for 15A.

Cobraguy,

Thank you for your help. I'm not exactly sure how to preform the load calculations. I attempted to review the '08 NFPA 70 NEC last night, but wow... A lot of information to try and digest. Wasn't really sure where to start.

Regarding the GFCI circuits answer, I had read that they should be run on a 10/2 - 20 Amp circuit. I didn't know if that was code related or just the gentleman's opinion who had written the basement remolding book.

Thank you for all your help.

By the way, is there a general rule of thumb regarding how many amp breakers that can be safely put into a 150 amp panel?

Oh come on, the code is too confusing? Never heard that before.

I will be back soon with the results of the service rating calcs.

Based on a 20 amp load, or 4800 VA of AC load, I arrive at a calculated connected load of 79 amps, which includes the new addition of the finished basement.

A 150 amp service should not be loaded more than 120 amps, therefore you will have a surplus of 41 amps capacity. The 150 Amp service is of sufficient size for the proposed addition.

As Cobra explained, a 20 amp circuit needs #12 wire, and 15 amp needs #14. Either can be with GFI receptacles. The #10 must be someone's opinion, or their experience with long distances and voltage drop.

Not sure what you mean by:

is there a general rule of thumb regarding how many amp breakers that can be safely put into a 150 amp panel?


The label on the panel will tell you the maximum size branch circuit breaker that panel can handle. Typically, the largest size allowed is 100 or 125 Amp breaker as a branch circuit.

If this does not answer your question, get back with more detail and explanation.

So, Article 220 makes your head spin?

He-he-he...

Some things are not as easy as it looks once you start reading the rules.