Michigan Administrative Code
Department - Licensing and Regulatory Affairs
Public Service Commission
Consumer Standards And Billing Practices For Electric And Gas Residential Service
Part 4 - METER READING PROCEDURES, METER ACCURACY, METER ERRORS AND METER RELOCATION
Section R. 460.115a - Meter accuracy and errors for electric customers only

(1) An adjustment of bills for service for the period of inaccuracy must be made for over registration and may be made for under registration pursuant to any of the following conditions:

(2) The amount of the adjustment of the bills for service must be calculated on the basis that the metering equipment is 100% accurate with respect to the testing equipment used to make the test. The average accuracy of watt-hour meters must be calculated pursuant to R 460.3616.

(3) If the date when the inaccuracy in registration began can be determined, then that date must be the starting point for determining the amount of the adjustment and is subject to R 460.115.

(4) If the date when the inaccuracy in registration cannot be determined, then it is assumed that the inaccuracy existed for the period of time immediately preceding discovery of the inaccuracy that is equal to 1/2 of the time since the meter was installed on the present premises, 1/2 of the time since the last test, or 6 years, whichever is the shortest period of time, except as otherwise provided in subrule (5) of this rule and subject to R 460.115(4).

(5) The inaccuracy in registration due to creep must be calculated by timing the rate of creeping under R 460.3101 to R 460.3804 and by assuming that the creeping affected the registration of the meter for the period of time immediately preceding discovery to the inaccuracy that is equal to 1/4 of the time since the meter was installed on the present premises, 1/4 of the time since the last test, or 6 years, whichever is the shortest period of time subject to R 460.115(4).

(6) If the average inaccuracy cannot be determined by test because part, or all, of the metering equipment is inoperative, then the utility may use the registration of check metering installations, if any, or estimate the quantity of energy consumed based on available data. The utility shall advise the customer of the metering equipment failure and of the basis for the estimate of the quantity billed. The same periods of inaccuracy must be used as explained in this rule.

(7) Recalculation of bills must be made on the basis of the recalculated monthly consumption.

(8) Refunds must be made to the 2 most recent customers that received service through the meter found to be inaccurate. If a former customer of the utility, a notice of the amount of the refund must be mailed to the customer at the customer's last known address. Upon demand made by the customer within 3 months of mailing of the notice, the utility shall forward the refund to the customer.

(9) If the external meter display is not operating so that the customer can determine the energy used, but the meter is recording energy correctly, then no adjustment is required. The utility shall repair or replace the meter promptly upon discovery of the failure.