Help determining if I need to upgrade the electrical service on my home

[wschenck311]

I searched the forums and found similar posts but they didn't answer my question. I'm hoping you all can help out with some math.

I currently have a 200amp service. My peak demand is ~12kW. I have this number from the POCO as well as hourly monitoring done by my solar power system. There are no electrical issues that I've noticed and the home is ~5 years old.

I want to add a swimspa that needs a 1x50amp and 1x60amp breaker at 240V. This will be on a subpanel installed in the backyard.

Is there enough current capacity in the system or do I need to upgrade the service?

 

[charlie b]

I am going to reopen this thread just long enough to answer the one question you asked. Then I will close it again. Forum rules do not allow us to assist a person who is not an electrician to perform their own electrical installation work.

Assuming the 12KW peak value is correct, here is what the electrician you hire to do this work will likely tell you. 12KW on a 120/240 volt system (standard for most houses) equates to 50 amps (12000/240 = 50). To be conservative, they will add 25% and declare your present load to be 65.5 amps. They will look at the specs for your swimspa to find out how much load it really draws. Then then can tell you whether or not you need to upgrade your service.

It's a good bet that a pair of 50 and 60 amp breakers will not actually draw 110 amps, let alone taking your present 65.5 amp load over the service limit of 200 amps. So I would say that the project is worth pursuing.