Adding a Subpanel for Electrical Service

CyinCo

Well-Known Member
Mar 24, 2006
5,745
254
63
Clive, IA
I have a house with 200 Amp service and I'm finishing the basement now. When I'm done running my basement circuits, my box will be full.

In the near future, I would like to set a hot tub outside. I'm going to pull the wire for the 50 Amp, 240Volt service required for the tub, however, with my box full, eventually I'll need a subpanel for that circuit.

So, some questions:

If my house is already 200 Amp, how many more amps can I put on the main service feed and be OK? Will 50 more Amps be an issue? It was built in 2007.

To add a subpanel, I'll need at least two spaces free for a bi-pole sub-breaker that feeds the subpanel main breaker, correct? If so, that means I'm also moving two circuits from the existing main panel to the sub-panel in order to free up those two spaces. That means that I can't simply add a 50 Amp sub, I'll need something larger. Should I do a 100 Amp sub?

I WILL hire this done by an electrician. I just want to understand what I'm getting into here.
 

besserheimerphat

Well-Known Member
Apr 11, 2006
10,478
13,007
113
Mount Vernon, WA
When we looked into doing geothermal last spring, they said that you need 400A service for the pumps. I thought I recalled the electrician saying that you needed some special stuff from the pole outside your house to get more than 200A inside the house. I don't remember what all he said, but you're probably looking at upgrading everything between the your breaker box and the grid... Good luck