[elknuts]

Hey guys, I have a question about a microwave that I am checking out, it is a ge spacemaker model jvm1871sk04. I am checking the input voltage at the HV transformer, in the past when i have checked these there have only been 2 wires, this one has 3 a red black and a blue, i get 120 across the black and blue but only 20 across the red and black, why are there 3 wires, and what should i see as far as voltage on each color combination. Any help is greatly appreciated, Bruce!!