Originally Posted by
datlas
Good question. I think one is for the 110 and one is for 220? That's my best guess.
Don't think so. Typically most houses have 3 wires coming in - 2 hot, and one neutral. Measure between either hot to the neutral you get 110 - measure across the two hots you measure 220.
I wonder whether at one time part of the house was rented out separately, and it was set up with a separate breaker box and meter.