VSD effect to energy meter?

[yogesh1997]

We have 10 energy meter in that 4x of them are giving the negative reading. The events shown are two 1is Negative Power Element 2 Warnings & 2. Negative Total Power Warning. The plant is not generating power & we are not sure where this export power coming from on site We have verified the voltage connection, CT reversal & alignment but all is fine. Supplied a new meter which shows the same readings. We have concluded the negative reading could be associated with the equipment connected. The “issues” with the meters are on DB boards where the board is connected to air handling units which are full of variable speed drives and I think that some of these may be DC drives. If that is the case, this may be causing the reverse power flow,??? What effect VSD’s will have on the meter readings?

[Khoa-Vo-Dang]

Please check this FAQ that may help: https://www.se.com/uk/en/faqs/FA86375/ before investigating the VSD side

[Col_W]

What model power meters are you using?

[yogesh1997 · Accepted solution]

We have checked with CT reversal and cabling everything fine but i don't know what is the strange here for getting negative reading?