I have someone reporting some abnormal readings on a residential 240/120 system. I cannot be there to verify. They are claiming, with no load, L1=120V L2=125V and N-G=1V. When loaded the measurements change to L1=120V L2=143V and N-G=20V (This person is not an electrician) Yes this points to an open or compromised neutral but why the 120/143 when loaded? All the open neutrals I have seen result in one leg dropping while the other increases the same amount, but in this case the total voltage appears to increase from 245V to 263V. For now I am figuring error on the part of the meter user, but is it possible for this to happen?
