We've got a manufacturing client in Charlotte getting hammered with power factor penalties from Duke Energy. Their billing shows 0.72 lagging PF but our Fluke 435 consistently reads 0.88 during the same billing periods. The penalty is running about $1,800/month on their GS-3 rate schedule. Anyone else seen this kind of discrepancy? We've requested meter testing but Duke is dragging their feet. The client has automatic PF correction but it's older ABB capacitor banks from 2003.
Duke Energy claiming 0.72 PF when our meter reads 0.88
Derek, I've seen this exact issue with TVA industrial customers. The utility meters often sample PF differently than our handheld units. Duke might be using 15-minute interval averaging while your Fluke is showing instantaneous readings. Check if your client has any large motor startups or welding equipment that could cause brief PF dips. Those transients can kill your monthly average even if steady-state PF looks good.
Had similar with TXU Energy down here in Dallas. Turned out the client's ABB caps were switching erratically due to failed contactors. The utility meter caught all the switching transients while our spot measurements missed them. Cost them $2,300 in penalties before we figured it out. I'd recommend logging PF continuously for a full billing cycle, not just spot checks.
Marcus makes a good point about the contactors. We see this all the time with Alabama Power customers using older correction equipment. Derek, have you checked the capacitor bank control logic? Those 2003 ABB units might have temperature compensation issues or the CT ratios could be wrong. Birmingham has several plants where the original installation specs didn't match actual load characteristics.
Thanks everyone. We pulled the ABB controller logs and found exactly what you're describing - the contactors are cycling on/off every few minutes instead of holding steady. The temperature sensor appears to be reading incorrectly causing constant switching. Client is getting quotes for replacement but in the meantime we're documenting everything for a penalty dispute with Duke. Anyone have success challenging PF penalties based on faulty correction equipment?
Derek, Georgia Power has been reasonable about penalty adjustments when we can prove equipment malfunction. Document the controller fault codes, get repair quotes showing the temperature sensor failure, and submit a formal dispute. Include your continuous monitoring data showing the PF would have been compliant with working equipment. They'll usually adjust 2-3 months of penalties if you have solid documentation.
Lee's advice is spot on. TVA has a similar policy. The key is proving the malfunction existed during the penalty period and that repairs will prevent future issues. Get the ABB service tech to document the failed sensor in writing. That technical report carries more weight than our analysis alone.
Update for anyone following this - Duke approved a $4,200 penalty adjustment after we submitted the ABB service report and repair invoices. They credited back three months of penalties once we proved the temperature sensor malfunction. New controller is working perfectly, PF steady at 0.96 now.