280 voltage on one leg

[Andymotosan]

I'm working on a GE vertical ptac unit m# AZ85HO9EACW1.

I had one that was giving me heat strips and Fan with 24 volts jumped to the compressor, fan and reversing valve leads at the control board. I thought ok we need a board. But when I was troubleshooting another unit I found that the power supply was 280V to ground on one leg and no power on the other leg. This is In a hotel and I have units that are actually working with this power situation. ???? Anyone have any wisdom on this?

Edited May 13, 2015 by Andymotosan

[Andymotosan]

Ok so I sorted out the voltage question. These things are rated at 265 nominal voltage. They run on one phase of 280 volt AC. 15 years in the biz and I never new. You learn something new everyday! So anyone out there sharp on the Alerton controls?