Why is power shown on my Smart Transformer meter negative but power factor is high?

Negative power means your system is generating (delivering/exporting) energy. If your meter is monitoring a generator system, you should see negative power and this is correct.

However, if your meter is monitoring a load that consumes energy, negative power (with high PF) usually results from 3 possibly reasons:

  • the voltage and current are not aligned OR
  • the CTs are mounted in the reverse direction OR
  • the CT leads are wired to the meter in the opposite direction.

Confirm that the voltage and current are aligned, for example, make sure phase ‘A’ correspond to voltage V1 and current I11 and I12 connections etc. Also make sure the P1/S1/H side of the CT faces the utility/source and that the black and white leads of the CTs are connected in the way specified by the CT manufacturer.

You can reverse the CT current direction for each line from the system parameters on the setting mode instead of physically reversing the CT (this can be done on the meter or through the software).

NOTE: This can only be done if the alignment is correct and the CT direction or lead order is the only things wrong.