Client installed capacitor banks 4 months ago to correct a power factor problem on PSO. The electrician confirmed PF improved from 0.78 to 0.94. But PSO is still billing a PF penalty every month. The bill still shows 0.78. What's happening?
Power factor penalty waived by installing capacitors — utility won't remove penalty from bill
The utility's PF meter might be upstream of where the capacitors are installed. If the caps were installed on the customer's side of the meter but the utility measures PF at the meter point before the correction, the meter won't see the improvement. Check where the capacitor bank is physically installed relative to the PF metering point. The caps need to be between the utility meter and the main loads to affect the billed PF.
Derek identified the most common cause. Another possibility: the capacitor bank is on a timer or controller that only activates during certain hours, but the PF penalty is based on the worst 15-minute interval in the month. If the caps are off during early morning or late night when some loads are still running, one bad 15-minute interval can trigger the penalty even though PF is excellent during business hours. Check the cap bank controller settings.
Bingo — the caps were installed downstream of the meter point. The electrician put them at the main distribution panel inside the building but the PF metering point is at the transformer outside. Moving the caps to the service entrance next week. Thanks for saving me a long wild goose chase.