Sandra H. in Wichita here. I've got a primary metered industrial client served at 13.2kV getting billed by Evergy on what appears to be wrong voltage transformer ratios. The CTs are definitely 1200:1 but I think the VTs might be programmed wrong too. Bills are running $180,000/month on Rate Schedule LGS-TOU when similar facilities are around $95,000. This is way over my head - anyone deal with primary metering multiplier issues?
VT and CT Ratio Errors on Primary Metered Account - Help!
Ken G. from Lincoln NE - Sandra, primary metering is tricky because you've got both CT and VT ratios that can be wrong. NPPD burned me on a case where the CTs were right but VTs were programmed 120:1 instead of 60:1. You need to verify both ratios independently. The VT nameplate should be accessible in the switchgear.
Randy Dawson here. Sandra, primary metered accounts are the most complex multiplier situations we deal with. You need to verify: 1) CT primary and secondary ratios from nameplates, 2) VT primary and secondary ratios from nameplates, 3) How these are programmed in the billing system, and 4) Whether the meter is calculating true RMS values correctly at primary voltage levels. I'd strongly recommend hiring a power engineering consultant who specializes in primary metering. The potential errors can be massive and utilities often resist admitting mistakes on these high-dollar accounts. Document everything before you make accusations.
Randy and Ken - thanks for the guidance. I'm definitely in over my head on this one. The client is getting desperate because cash flow is being killed by these bills. Do either of you know consultants who specialize in primary metering audits? I don't want to screw this up.
Hank B. in Minneapolis here. Sandra, I've used Power Systems Engineering out of Denver for primary meter audits. They found a VT ratio error on our Xcel Energy account that was costing $40K per month. Worth every penny of their fee. Xcel initially fought the findings but eventually paid full adjustment.
Marcus W. from Memphis - be very careful with primary metered accounts. MLGW tried to claim our consultant's findings were wrong until we got an independent PE to verify. The utility had been using 100:1 VT ratio when actual transformers were 69:1. Took 14 months to resolve but got $127,000 refund.
Marc H. in Bakersfield - Sandra, also check if they're applying demand and energy multipliers consistently. PG&E had our primary account with correct energy multiplier but wrong demand multiplier for 8 months. Schedule E-20 bills were totally screwed up until we caught it.
Update - hired the consultant Hank recommended. They found VT ratio programmed at 110:1 when actual is 220:1, so we've been getting doubled bills for 11 months. Evergy is finally admitting the error after seeing the PE report. Looking at $850,000+ refund. Sometimes you have to spend money to save money!