Phase 3 AC units, running backwards a problem?

At work we had an electrician come and replace the electrical box out back and when we turned the AC on, it worked, but barely. We went on the roof where the unit is and noticed it was in thermal overload, so we cooled it off, then turned it back on and noticed it was running backwards? Is this a problem? We had somebody come out and tell us that it's shot, but not the building owners fault and that he's not responsible. But if the electrician hooked it back up wrong, then it's not our fault but the electrician's right? We lease our office space. Any help is greatly appreciated.

Sorry, I should have mentioned before. My boss did HVAC for a living prior to owning our business and when he saw that it ws running backwards, he switched thw wires around and tried it. It would run for a minute or two, then turn off, but even when it ran it wouldn't cool the air. So we switched them back and called the electrician back to take a look. He said that the converter is shot.

The electrician hooked up the 3 phase lines in the wrong order. This will cause a 3 phase motor to turn in the opposite direction. Have him come back and rewire the box he installed. Before he leaves have him start the AC unit to make sure it is operating correctly

it is doubtful the unit is shot as overload in compressor would keep it turned off ....all you have to do is change any two lines coming to unit and it should work fine....the man who came and checked your unit should nave done this before he told you it was shot....if he didnt then call electrician and have him come and change the wires on box he installed...shouldnt take him long and this should be free as he should have made sure he got all the lines back in the right order..

Yeah, that's a problem, they don't work well running backwards. If you can't get the electrician to settle the matter, it is simple to fix. Go to where the main power wires connect to the unit, there should be 4 wires, 1 being ground. The 3 hot wires will be accessable, switch ANY 2 hot wires and the unit will run the opposite direction. Please make sure that the power is off.

HMM, maybe he should have used a phase rotation meter to determin the proper rotation.....