Gary Parker from the ECA gives guidance on the THD readings a Voltimum user has recently measured.

This Q & A is one of the thousands posted in our Technical Expertise area and answered by our Voltimum Experts.
Question:
The total harmonic voltage distortion (THD) of a neutral conductor is between 190- 320% But the line conductors are between 1-3%. Could you confirm that the neutral value is exceptionally high and also common causes of this?
Answer:
Gary Parker, ECA
It does seem very high indeed.
I would suspect that there are large amounts of electronics in this installation causing this. It may be that you look to balance loads or increase neutral CSAs, providing the distortion is coming from your side, not the distributors.