Section 69-09-02-25 - Meter testing equipment1. Each utility shall maintain sufficient laboratories, meter testing shops, secondary standards, instruments, and facilities to determine the accuracy of all types of meters and measuring devices used by the utility.2. Each utility maintaining primary standards such as precision wattmeters, volt boxes, resistances, and timing devices shall have such standards certified at the time of purchase as to accuracy by a recognized laboratory other than that of the manufacturer of the standard.3. Utilities not maintaining standardization laboratories may obtain authorization from the commission to have their standards certified for them by an approved laboratory.4. Secondary watt-hour meter standards shall not be in error by more than plus or minus three-tenths of one percent at loads and voltages at which they are to be used, and shall not be used to check or calibrate working standards unless the secondary standard has been checked and adjusted, if necessary, within the preceding twelve months. A history and calibration record shall be kept for each secondary standard watt-hour meter.5. Any two or more of at least three watt-hour meters may be used as a secondary standard to check portable rotating standards provided there is no discrepancy in accuracy between any two of the watt-hour meters used by more than two-tenths of one percent at standard test loads. Calibration and history records shall be maintained for each of the meters used as secondary standards.6. Secondary standard indicating instruments shall not be in error by more than plus or minus one-half of one percent of indication at commonly used scale deflections, and shall not be used to check or calibrate portable indicating instruments unless the secondary standard has been checked and adjusted, if necessary, within the preceding twelve months. A calibration record shall be maintained for each standard.7. All working rotating standards, when regularly used, shall be compared with a secondary standard at least once a month if they are of the commutator type, and at least once in every six months if of the induction type. Working rotating standards infrequently used shall be compared with a secondary standard before they are used.8. Working rotating standards shall be adjusted, if necessary, so that their accuracy will be within plus or minus three-tenths of one percent at unity power factor, and within plus or minus one-half of one percent at fifty percent lagging power factor at all voltages and loads at which the standard may be used. A history and calibration record shall be kept for each working rotating standard.9. The meter accuracies herein required for all primary, secondary, and portable standards shall be referred to one hundred percent. Service measuring equipment shall be adjusted to within the accuracies required assuming the portable test equipment to be one hundred percent accurate; provided, that a utility may use calibration records to compensate for known errors of secondary standards and working standards in adjusting service measuring equipment.N.D. Admin Code 69-09-02-25
General Authority: NDCC 49-02-11
Law Implemented: NDCC 49-02-11