I've got a minor problem and I'll bet the readership here can help me solve it.
32x100' building with new 200 amp service panel mounted about 25' from the front. There is a 70 amp box added about 25' from the main on a circuit from the main 200A box(with #4 AWG wire). I want to continue that wire back another 30' and install another breaker box in a garage area after I change the 70A breaker in the 200A main panel to a 100A breaker. This auxillary box will control a central air/heat unit,an electric H/W heater,a dryer,two bathrooms,two bedrooms,and of course the 24x32 garage. I want to have 220V hookups for a 50A welder,a 30A plasma cutter,a 30A air compressor and the various wall plugs everywhere.
Can I jump from the 200A main panel to a 100A auxillary panel in this manner and have a fully functional electrical system? Will the #4 AWG handle such a setup or do I need to go to #2 AWG?
I've been told that the maximum auxillary box is the existing 70A circuit (70A breaker in the main panel) I know they make the 100A breakers that can be used to replace the 70A that's already there(any problem with that?)
I should explain... This is an old Firehouse(brick walls..tin ceiling) that the front 1/3 was totally renovated..all firerock and all new wiring in flexible conduit...believe me it's right($30 grand worth by the PO). We are adding 3 BR & 2 Baths and the all important work area. I really don't want to run 50-75' homeruns from the main panel to the back 2/3's if I can install a 100A panel off the 200A main back in the shop...from there the longest run would be 15-25'.
I know just enough about wiring to get by,but I know some of you deal with this as a profession...your input would be appreciated.
Thanks for any insight into this--Dave