We were getting a neutral to earth voltage of 3v during off peak hours and 6-7v during peak load time.Is it due to harmonics ? or poor conductors or some other issues ? is there any device to protect the main UPS from harmonics?
Sorry Sajeev, it's probably due to a poor earthing system and Ohm's Law, I should imagine. It could even be due to too many spurs (instead of ring mains circuits). That is, loads effectively in series, rather than parallel. But, to be specific, where are the potentials you mention actually being measured ... at the outlet where the unit is located (after all, that's what matters in this case)?
