Hi, I just bought a house it has an 100A Main at the house and a 100A sub panel in the garage. The wire is buried underground about a 50ft run and it is 10-3. I have a lot of wood working tool and would like to make it a shop. I was just wondering is 10-3 sufficient from panel to panel because I thought it should be 2 or 4 gauge?
The breaker is correct, a 10-3 wire is capable of carrying 30 amps, 240 volts, no more. If you need more current capacity, you will need to install a larger capacity 4 wire cable, and an appropriate panel in the garage. There are dozens of threads on this forum with detailed instructions on how to make such a connection, just do a search.