Hey Gang,

I have 240v service coming in from outside. There are three wires--two hot and one neutral. I am not sure what gauge the service wire is.

It comes into the panel and is connected to a 60 amp main breaker. But the wire going into the 60 amp main breaker looks narrower than the wire coming in from the street.

Does that mean that each of the hot wires are 120 V and 30 amps (for 240 V and 60 amps total?).

Or is it calculated some other way? Is the main breaker always sized to the maximum current that the service wires can carry?

By the way, this is a Square D QO breaker box.

Thank you!