HI Sean. Can you help with what instrament/and the "how to" to check phase? I am doing maybe the unthinkable. I take a 3 wire 220 air conditioner circuit( 2 20 amp breakers joined in the box) black and white are both hot/the bare copper,being the neutral. A black and the bare copper being one outlet. The white and the same copper being another outlet.I have been doing this for 7/8years.-----But,how to tell;are they phase?