What should i get 100A or 200A double-throw main switch for my 125A main panel?

Question

Here is the thing I need a main double-throw switch before my 125A main panel but the problem is there is no 125A main switch. The standard are 30A, 60A, 100A, 200A. what would be the best 100A or 200A

Answer 1

From what you wrote, I guess you mean a 2 pole main breaker for the 125 amp panel.Contact the AHJ and ask the inspector what would be approved.  IMO the 100 would not, the 200 is more than the panel is rated, so ask the AHJ.  

Answer 2

You have to go with the 100 amp it has to be the same size or smaller then the wire rating, you could order a 125 amp breaker if you wanted to , they do make them

If you are talking about a non fused disconnect switch you can and have to use anything over the 125 amp, so the 200 is what you want to use

Answer 3

you cant use a non fused disconnect as a main disconnect for your 125a main lug panel.you need a 100a fused disconnect as your first means of disconnect for your 100a service .and the term is single pole ,double throw,even though you don't need that info.100a,240volt,fused nema 3r disconnect is all you need

Answer 4

100 amp would be the best because 200 amp would exceed the capacity for you panel. That would be dangerous.