R8‑12 METER ACCURACY
(a) Creeping. - No watt hour meter which registers on "no load" when the applied voltage is less than one hundred and ten percent (110%) of standard service voltage shall be placed in service or allowed to remain in service.
(b) Initial Accuracy Requirements. - No watt hour meter shall be placed in service which is in any way mechanically defective, or which has incorrect constants, nor shall any watt hour meter be maintained in service which is not adjusted to meet the following requirements:
Average error not over 2% plus or minus;
Error at heavy load not over 2% plus or minus;
Error at light load not over 4% plus or minus.
(c) Adjustment after Test. - Whenever a test made by the utility or by the Commission on a service watt hour meter connected in its permanent position in place of service shows that the average error is greater than that specified above, the meter shall be adjusted to bring the average error within the specified limits.
(d) Allowable Error. - A service watt hour meter having an average error of not more than 2% plus or minus, may be considered as correct, and no adjustment of charges shall be entailed by such an error.
(NCUC Docket No. E‑100, Sub 29, 11/29/77.)