Did something stupid today wired up a tank pump live and neutral to an old daikin r407 unit only to find that lead number 2 on this particular unit was the comms and 3 was the neutral I soon worked this out after the u4 came on the controller so sorted it out and the unit ran fine with no issues so cut a long story short I had to leave site without checking the pump.could I of blown anything in the pump by putting the the neutral of the pump in the comms cable?