I'm new here so please bear with me. I'm currently working as an outside contractor for a manufacturing facility. We are installing around 30 machines which are all 240 volt 3 phase. The company insisted on purchasing a used 225 kva transformer and a used 400 amp bussway. The transformer and bussway voltage all test fine until a load is applied, then one phase drops to 0 volts to ground while the other 2 read 240 volts to ground. When you test across the phases they all read 240 volts. Approx. 6 machines of the 30 are up and running and they all run fine. One of the machines has been running parts for 3 days and they're the type of company that if a machine wasn't working they would be on the phone to let me know about it. The transformer has a grounding conductor from the panel which it is fed from and also a ground to building steel. It is a delta to delta transformer 480 volts to 240 volts with no XO tap. I was fully expecting to have one high leg, but not to have one with no voltage to ground. I appreciate your time and thoughts.