Elmer R. here from Springfield, Missouri. Got a primary metered industrial account that's been getting hammered on their electric bills. Customer is on Ameren's Large Power Service rate and their monthly bills jumped from around $85,000 to over $340,000 starting in March with no operational changes. Finally got out there last week and discovered the VT ratio in the billing system is 10:1 but the actual VTs are 100:1. That's a 10x overbilling for five months running. Customer is owed about $1.2 million in credits. Anyone dealt with VT ratio errors this large before?
VT ratio error on primary metered account - massive overbilling
Elmer, that's an enormous billing error that will require very careful documentation and likely legal involvement. Randy Dawson here from Memphis. Primary metered VT errors are less common than CT issues but when they happen the impact is massive as you're seeing. First priority is getting Ameren to immediately correct the billing going forward, then work on the historical adjustment. With $1.2 million involved, I'd strongly recommend getting the customer's legal counsel involved early in the process. Document everything - nameplate photos, meter test data, billing analysis showing the exact error period. What does Ameren say about when this error started?
Randy, Ameren claims they don't know when the error started - they're saying their records show the VT ratio has been 10:1 'for years' but obviously that's wrong since the customer's bills were normal before March. I suspect they changed something during maintenance work in February but they're not admitting to any service calls. Customer's attorney is already involved and we're pushing for a complete audit going back 24 months. The meter test data clearly shows 100:1 VTs so there's no question about the physical installation. Elmer R.
Jennifer R. from Sacramento here. Had a similar VT ratio case with SMUD few years back, though not nearly as large. The key was getting their field engineering group to provide a detailed timeline of any work performed on the account. Even if they claim no maintenance was done, there should be records of meter readings, system changes, even software updates that might have triggered the error. Push hard for their internal work order history - something caused that ratio to change in March.
Jennifer, that's a great point about work order history. We're requesting all maintenance records and system change logs from January through March. Customer mentioned they had some power quality issues in February that required Ameren to come out, so there definitely was some kind of service activity around that timeframe. Will keep pushing for those internal records. Elmer R.
Carl N. from Denver. Elmer, one thing to watch out for with VT errors is whether they affected both energy and demand billing consistently. Sometimes the VT error only impacts one component depending on how their billing system is set up. Make sure your calculation methodology accounts for TOU energy rates and demand charges separately. With $1.2 million at stake, Ameren will scrutinize every detail of your adjustment calculation.
Carl, good catch. We've verified the VT error affected both energy and demand calculations consistently, so at least that simplifies the adjustment math. The customer is on a complex TOU rate with seasonal variations, so we're having to recalculate every billing period individually. Ameren finally provided some maintenance records showing they replaced a VT in February - supposedly unrelated to the billing issue but the timing is awfully suspicious. Elmer R.
Elmer, that VT replacement in February is likely the smoking gun you need. Equipment replacement often involves reprogramming meters or billing systems, which creates opportunities for data entry errors. Push Ameren for the specific work orders related to that VT replacement and any associated meter programming changes. With that timeline established, you should be able to limit the adjustment period to March forward rather than having to fight over longer lookback periods. Randy Dawson.
Update: After six months of back and forth, Ameren finally agreed to the full adjustment back to March. Total credit of $1,147,000 being applied over the next 12 months to avoid cash flow issues. The VT replacement work order from February showed they updated the meter programming but entered 10:1 instead of 100:1. Simple data entry error with massive consequences. Customer is also getting interest on the overbilled amounts. Thanks Randy and everyone for the advice - the work order angle was crucial. Elmer R. in Springfield.