Skip to content

Metering

Meter multiplier errors

The billing system multiplies register readings by the wrong constant, usually after a meter or current transformer exchange.

How often we find it
Found on roughly 1 in 60 transformer-rated meters we audit
Typical impact
Often 25% to 100% of the account's usage charges while the error lasts

Large commercial services are measured with transformer-rated meters. Current transformers (CTs), and at higher voltages potential transformers (PTs), step the service down so a standard meter can measure it. The meter's dial or register then records only a fraction of the real flow, and the billing system multiplies each reading by a constant to restore actual kWh and kW. For an 800:5 CT the multiplier is 160; with a 2:1 PT as well, it is 320. The multiplier lives in the utility's billing record, not on the meter face, so when a technician swaps a meter, upgrades CTs or changes the service, the record must be updated by hand. When it is not, every reading is scaled by the wrong number. The result is a step change in billed usage that does not match the building's operations, sometimes doubling the bill overnight. Under-billing happens too, and utilities can back-bill for it, so findings need care before filing.

How it happens

  • CTs were replaced with a different ratio during a service upgrade and the billing record kept the old multiplier.
  • A meter exchange moved from a self-contained meter to a transformer-rated meter, or the reverse, without a multiplier change.
  • A meter with an internal multiplier was installed where the billing system applies an external one, scaling usage twice.
  • kWh and kW (or kVARh) registers carry different multipliers in the billing record.

How to detect it

  • Look for a step change in kWh or kW that coincides with a meter number change on the bill.
  • Divide billed usage by the register difference to back out the multiplier the utility applied, and compare it to the CT and PT ratios on site.
  • Compare billed demand to the service's physical capacity: billed demand above what the service can deliver points to a multiplier error.
  • Check that consumption tracks occupancy, production volume or degree days before and after the change.

Evidence the utility will accept

  • Bills before and after the meter or CT change, showing meter numbers and register reads
  • Photographs of the CT nameplates and meter face showing ratio and any internal multiplier
  • The utility's meter exchange or field work order
  • Interval data showing the step change in recorded usage

Recovering the overcharge

We file a metering dispute with the nameplate photographs, register math and the work order date, and request a field verification of the CT ratio and multiplier. Once confirmed, utilities rebill every month since the change, usually within the back-billing limits of their tariff or state rules. These claims are among the fastest to resolve because the arithmetic is unambiguous once the ratio is verified on site.

Questions we get asked

Some bills print it next to the meter reading as a constant or multiplier. Others do not, and you back it out by dividing billed usage by the register difference.

The utility can usually back-bill for under-billing within its tariff or state limits. We tell you before filing anything so you can accrue for it.

Once the utility completes a field check, rebilling usually follows within one to two billing cycles.

Find this error in your own bills.

Connect bills for up to 50 meters. Get the findings report in about three weeks. Pay nothing unless money comes back.

Start free trialExplore demo
from bill access to first findings report
21 daysfrom bill access to first findings report
of filed claims accepted by the utility in full or in part
94%of filed claims accepted by the utility in full or in part