Section 1220-04-04-.39 - FACILITIES AND EQUIPMENT FOR METER TESTING(1) Each utility shall maintain a meter shop for the purpose of inspecting, testing and repairing meters. The shop shall be open for inspection by authorized representatives of the Authority at all reasonable times, and the facilities and equipment, as well as the methods of measurements and testing employed, shall be subject to the approval of the Authority. A utility may, however, have all or part of the required tests, repairs and adjustments made or its portable testing equipment checked by another agency approved by the Authority and having adequate and sufficient testing equipment to comply with these rules. (a) Each location at which the utility conducts tests of meters shall have three (3) phase voltage supply, one (1) phase of which shall be variable from zero (0) to two hundred seventy (270) volts.(2) Secondary Standards(a) Each utility shall have at least one (1) electronic watt-hour standard meter with a correction of not more than two-tenths percent (0.2%) at commonly used loads. If the correction percentage varies between successive tests by more than one quarter percent (0.25%) a complete check must be made to determine the cause of such variation. If the cause of variation cannot be removed, the use of the instrument should be discontinued.(3) Working Standards(a) Each utility shall have at least one (1) portable electronic watt-hour standard meter with a correction of not more than three-tenths percent (0.3%) at commonly used loads. If the correction percentage varies between successive tests by more than one quarter percent (0.25%), a complete check must be made to determine the cause of such variation. If the cause of variation cannot be removed, the use of the instrument should be discontinued.(4) Secondary standards must be checked periodically (see Rule 1220-4-4-.35(2)) at the National Institute of Standards and Technology (NIST) or any successor thereto or at a utility's option, at a laboratory traceable to NIST.(5) Working standards must be checked periodically (see Rule 1220-4-4-.35(2)) by comparison with a secondary standard in the utility's meter shop.(6) Extreme care must be exercised in the handling of standards to assure that their accuracy is not disturbed.(7) Each standard shall be accompanied at all times by a certificate or calibration card, duly signed and dated, on which are recorded the corrections required to compensate for errors found at the customary test points at the time of the last previous test.Tenn. Comp. R. & Regs. 1220-04-04-.39
Original rule certified May 9, 1974. Amendment filed October 30, 2000; effective January 13, 2001.Authority: T.C.A. § 65-2-102.