I took a look at some of the other threads, but none seemed to give me a clear answer:

My house currently has a mess of a load center setup that I need to correct. There are two Square-D 22? space panels wired to each other, with one being a subpanel with a 60 AMP link from the primary one (there is a 60 AMP breaker in each panel that are linked together with some super-thick aluminum braided wire). The primary panel has a 100 AMP main breaker, connected to the meter outside.

Aside from this thing being a monstrosity, the "subpanel" has corrosion in spots on some of the breaker contact points, reducing voltage to 108 or so on some circuits (diagnosing why some things worked and others didn't when plugged into certain outlets was a multi-day adventure.) The thing that just pushed me into action is that the screw-downs for the feed from the meter on the 100 AMP breaker are corroded, and one is actually loose and occasionally arcs.

I don't have a lot of vertical space to go with a 200 AMP panel with a lot of spaces. I can get the same footprint Square-D panel with either a 100 AMP or 125 AMP main breaker. I can also reduce the number of breaker spaces I need by consolidating circuits (LOTS of the interior outlets are direct runs to the panel, there's no reason the LR, for example, can't all be on one breaker instead of 3), and by using a few tandem breakers.

My questions:

• Does going from a 100 AMP to a 125 AMP panel require any change in the gauge of the wire coming from the meter?
• Is there any limit to the number of tandem switches that can be used in one of these panels (e.g., Square-D HOM2448M125PC)?

Thank you!

John