(A) Adjustments Due to Meter Errors. If any service meter, after being tested as provided in these rules, is found to have a percentage of error greater than three percent (3%) for watt hour meters and four percent (4%) for demand meters, the bills for service shall be adjusted as follows:
(1) Fast Meters — When a meter is found to have a positive average error, the Corporation shall refund or credit the customer’s account with the amount of any charges in excess of either (i) an average bill for the kilowatt hours and/or demand units incorrectly metered or (ii) separate bills individually adjusted for the percent of error for the period the meter was fast, if such period can be determined, or one year, whichever period is shorter. An average bill shall be calculated on the basis of kilowatt hours and/or demand units registered on the meter over corresponding periods either prior or subsequent to the period for which the meter is determined to be fast. No part of a minimum service charge shall be refunded.
(2) Stopped or Slow Meters — When a meter is stopped or has a negative average error, the Corporation may charge the customer for the kilowatt hours and/or demand units incorrectly registered for one-half of the period since the last previous test or one year, whichever is shorter. The amount of the charge to the customer shall be estimated on the basis of either (i) an average bill as herein below described or (ii) separate bills individually adjusted for the percent of error. An average bill shall be calculated on the basis of kilowatt hours and/or demand units registered on the meter over corresponding periods either prior or subsequent to the period for which the meter is determined to be slow or stopped. The Corporation may charge the customer for such amounts except where the Corporation negligently allows the stopped or slow meter to remain in service.
(B) Other Billing Adjustments. Any and all other billing errors, including incorrect rate or rate schedule applications, shall be adjusted to the known date of error or for a period of one year, whichever period is shorter.