I’ve just had a 3em installed and am getting a negative reading on phase 1 when there is no load. When I turn on my 3p bore pump all phases show with positive values in the right range, so the current clamps are correct. I have double checked the clamps and voltage wiring is correct to the right and matching phase. Is this now a calibration issue? I understand they should be calibrated from factory.
No load reading
Bore pump operation
Switchboard wiring