Originally Posted by
Handyman2007
There isn't a "2 phase" electrical service. There are three(sometimes four) wires. One pole is 120, the other is 120 , a neutral and now an equipment ground.
The "unused white neutral" should be connected to the same terminal as the ground (green). The breaker needs to be reduced to 30 amps. If you are not sure how to do this, to err on the side of caution, pay an electrician to do it for you. I have done a lot of electrical work in the last 40 years,,,,,it's only friendly if you KNOW WHAT YOU ARE DOING!!! Good Luck.
Never refer to a breaker as a "switch". They are not designed to be used as switches.