PSC 113.0904PSC 113.0904 Watthour calibration. Each utility which normally checks its own working portable standard watthour meters or instruments against primary or secondary standards shall calibrate these standards or instruments before they are submitted to a commission-approved test facility annually and attach to them a record of such calibration.

PSC 113.0905(1)(1) In all tests of watthour meters where comparison of revolutions is made, at least 2 revolutions of the meter under test shall be taken at light load and at least 9 revolutions at heavy load. At least 2 checks shall be made at each load. The accuracy of the meter under test at each load shall be the average accuracy determined from 2 checks taken at the same load which must agree within 0.2 of 1%. However, if an electro-optical testing device is used, the test procedure may be modified, provided equal accuracy of the method is maintained.

PSC 113.0905(2)(2) If the watthour meter has a contact device which operates a demand mechanism, the disk revolutions when testing should be multiples of the number of revolutions per contact in order to take account of the varying friction which may be present during the movement of the contact cam from one contact to the next.

PSC 113.0905(3)(a)(a) Single-phase test with the potential circuits connected in parallel and all current circuits connected in series. Three-stator, 4-wire delta meters must have correct values of current and potential applied to the differently rated circuits. The normal test loads apply. (See s. PSC 113.0811 (1) (c).)

PSC 113.0905(3)(b)(b) Individual stator test with the potential circuits connected in parallel and each current circuit tested separately. (For 2-stator, 4-wire delta meters, the current circuits of the 3-wire stator should be connected in series and treated as a single circuit. Three-stator, 4-wire delta meters must have correct values of potential applied to the differently rated circuits.) The light load test current shall be one-tenth N times the reference test current and the heavy load test current shall be between one-half and one N times the reference test current but not more than twice the test ampere rating of the meter. (N equals the number of stators in the meter except for 2-stator, 3-phase, 4-wire wye meters. For the latter, N shall be 4 for the current circuits which are not common to both stators and N shall be 2 for the current circuit common to both stators.)

PSC 113.0905(3)(c)(c) Individual stator test with the potential circuits connected to the polyphase circuit in the same manner as in service. (For 2-stator, 4-wire delta meters the current circuits of the 3-wire stator shall be connected in series and treated as a single circuit.) The light load test current shall be one-tenth N times the reference test current and the heavy load test current shall be between one-half and one N times the reference test current but not more than twice the test ampere rating of the meter. (N equals the number of stators in the meter except for 2-stator, 3-phase, 4-wire meters. For the latter N shall be 3 for each current circuit.)

PSC 113.0905(3)(d)(d) Polyphase test with the meter connected to a polyphase circuit in the same manner as in service, with balanced polyphase currents on the current circuits. This requires the use of a polyphase standard watt-hour meter or as many single-phase standards as there are current circuits under test.

PSC 113.0905(4)(4) Instrument transformers shall be tested with a burden equivalent to that with which they are to be used or with burdens from which curves showing the accuracy of the transformer can be derived. Any approved method may be used for testing instrument transformers. Also see s. PSC 113.0916.

PSC 113.0906(1)(1) For meters with block-interval demand registers, demand interval timing check shall be performed and a determination made that the pointer pusher or test dial pointer has reset to zero at the end of the billing period demand interval.

PSC 113.0906(2)(2) Demand registers used with instrument transformer rated watthour meters shall be tested with the demand register mounted in a normal operating position on the watthour meter. The demand registered on the demand meter during the test shall be at least 30% of full scale with the demand test interval varying from a fraction of an interval up to a full interval.

PSC 113.0906(3)(3) Demand registers used with self contained watthour meters shall be tested with the demand register mounted in a normal operating position on the watthour meter. The demand registered on the demand meter during the test shall be equivalent to the test ampere rating of the watthour meter with the demand test interval varying from a fraction of an interval up to a full interval.

PSC 113.0907(1)(1) The test of block-interval pulse-operated demand meters and pulse recorders shall include a check of the electrical and mechanical operation of the demand register or pulse recorder, an inspection of the pulse initiator and a check to determine that the demand meter resets properly.

PSC 113.0907(2)(2) A demand meter or pulse recorder, its associated pulse initiators, relay and circuitry may be considered to be operating properly when a kilowatthour check indicates that the demand meter kilowatthours are within the required accuracy limits of the watthour meter kilowatthours.

PSC 113.0908(1)(1) Each measurement circuit of an electronic meter shall be tested in accordance with the requirements of s. PSC 113.0905. Internally calculated quantities, such as in a multifunctional meter, are not normally subject to test.

PSC 113.0909PSC 113.0909 Methods of testing electronic registers. Necessary tests or checks shall be made to determine that the correct program is in the meter, that the correct register is active as determined from the program, that the meter is displaying the correct date and time and that the meter’s battery mode is working and will retain register programs and recorded data during loss of power.