| You want to add a fourth panel? Do you want to take power from the main panel or one of the other subpanels? Have you done a demand locad calculation?
Is simply replacing the existing subpanel in the basement with a larger one an option?
You mention that you have an existing subpanel in the basement, and you listed all the loads on it. What you didn't say is what loads will be on the new subpanel you are asking about. And tell us how many square feet of finished space will be supported by this new panel.
I'm a bit confused so far.
The way to size a panel is:
1. Figure out what loads will run from it, including planning something spare for the future.
2. Figure out how many watts each of those loads uses.
3. Figure out what will realistically be on simultaneously.
4. Add all those up to get some number of watts.
5. Divide those watts by 240 to get amps.
6. Add a fudge factor to give you a margin of error.
7. Put in a subpanel rated for at least that many amps.
8. Put a breaker in the feeding panel for no more than that many amps.
9. Size the feeder wire based on the feeding panel breaker size.  |