I getting new 200Amp service to surface mount service panel. I want to run 2oo cable to bring it sub panel in my Garage which is approx 120Ft Run through ceiling.

2 Questions

1. Is there any ristriction on running a 200AMP inside house to garage ?
2. I got a dirt cheap subpanel that has circuit breaker for 200AMP can I have 2 circuit breaker of same size one out side in service panel and one on sub panel.

I am in City of Sunnyvale, CA

Thanks in Advance.

Rob

Don't know your total distance or loads, if total is a long run, may want to use 3/0, instead of 2/0 Copper. I don't do aluminum.
TK is a local specialist, could give good advice on this. Particularly Making the connection,
Bug or Lug solution.
You can have a 200 amp protecting another 200 Amp Panel.
If it is for garage, You may be OK with 100 Amps, 100 Amp Breaker Will Plug right in first panel.
200 Amp Panel doesn't have to have 200 Amps.