Basic Question 220v polairity

Discussion in 'General Electronics Chat' started by jcc2010, Apr 23, 2011.

  1. jcc2010

    Thread Starter New Member

    Apr 23, 2011
    The attached picture is from an RV transfer switch which burned out and I am replacing...

    Shore Power "IN" (far right) is 220v, 50amp, wired
    HOT 1 = Red,
    HOT 2 = black.

    Both the Load Panel and the Generator are wired just the opposite:

    HOT 1 = black
    HOT 2 = red

    Does this matter? I know polarity matters, but not sure if this would affect polarity. I just noticed the difference and thought I should check!!!

  2. SgtWookie


    Jul 17, 2007
    There are labels on the white sheet below the wires that indicate what should be connected where.

    I would simply connect them back up as they are now.
  3. DigitalReaper


    Aug 7, 2010
    Those bare earth wires should be sleeved too, that's just begging for a short circuit...
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    You can think of a 220V system as two 110V lines cross-linked. I will not say tied together as there is a phase difference.

    In a 220V system both the red and black wires carry the voltage, and the green or bare wire is earth ground. Each red or black wire carries 110V to ground, but since they are 180 degrees out of phase they carry the full 220V between them.

    So swapping red and black really makes no difference, though it seems to me the builder was a little sloppy. I personally would keep red to red and black to black, though it will not harm anything if you leave them as they are.
  5. Jotto


    Apr 1, 2011
    I used to do commercial and residential electrical. My boss would have told you to pull it all out an start over. The length of the wire should have been longer and bent inside of the box. The ground should have never been run over the buss, they should have went along the bottom an up the side to the ground bar, also would change the side the ground wire goes in. Those buss bars allow you to go in from either side.