I stand corrected, 240v not 220v so I hope my question now makes sense.
I have 2 30amp breakers connected together. I believe this gives me 240v. I plan to connect this circuit to a 240v irrigation pump. It looks like the original wire from the main circuit is 12 gauge. The pump will be around 160' from the breaker. can I use 10 gauge wire from the back of the house to the pump or must I use 12 gauge? The distance from the back of the house to the pump is around 100' I would like to mention that the wire will go from the house to a relay box then to the pump. The relay is going to be connected to the irrigation timer and the water pump. We live in Melbourne, FL.