Karen W. from Charlotte NC. Duke Energy replaced our old mechanical meter with new AMI last month and the January bill is way off. Previous bills were running 850-900 kW peak demand, new meter showing 425 kW. Connected load hasn't changed and we're on Schedule SGS-TOU. Looks like they programmed wrong CT multiplier in the new system.
AMI Programming Error After Meter Swap
Greg L. Indianapolis IN. AES Indiana did same thing to us two years ago. Old meter was reading correctly with 600:1 CTs, new AMI got programmed for 300:1. Cut our bills in half which looked great until they caught it six months later and hit us with a huge back-billing adjustment. Better to catch it early Karen.
Greg that's exactly what I'm worried about. Rather find and fix it now than get hammered later with back billing. Problem is Duke is saying the new meter is reading correctly and our load must have dropped. But we've added equipment since December so load should be higher not lower. How do I prove the multiplier is wrong?
Scott H. Denver CO. Karen, check if they actually changed the CTs when they swapped meters. Xcel sometimes installs new CTs with different ratios during AMI upgrades. If they kept the old CTs but programmed new ratios you've got a problem. Also compare the meter constants between old and new bills if they show them.
Randy Dawson here. Karen, you need to request the meter programming details from Duke and compare the CT ratios in their system against the actual CTs installed. Also ask for the calculation worksheet showing how they derived your kWh and demand readings. If your load profile hasn't changed significantly, the demand readings should be consistent. What's your typical monthly kWh usage - did that change proportionally too?
Randy, monthly kWh also dropped from about 285,000 to 142,000 which confirms the multiplier is wrong. Everything got cut in half. Duke finally agreed to send someone out to check the programming but they're saying it could take 3-4 weeks. Frustrating when the math is so obvious.
Arnold K. Bismarck ND. Montana Dakota Utilities pulled this exact stunt on a client. New AMI meter, wrong programming, bills cut in half for four months before they caught it. Back billing was over $18,000. Fight to get it fixed now Karen. The longer it goes the bigger the eventual adjustment.
Update: Duke finally sent tech out and confirmed the AMI system was programmed wrong. CTs are 600:1 but meter was reading as 300:1. They're correcting it and will adjust February bill to include the underbilling from January. At least they admitted the mistake quickly once they actually looked at it.