PSC 113.0811(3)(3)Meters used with instrument transformers shall be adjusted, if necessary, so that the overall accuracy of the metering installation will meet the requirements of this rule.
PSC 113.0811 HistoryHistory: Cr. Register, July, 2000, No. 535, eff. 8-1-00; CR 02-027: r. (4), Register December 2002 No. 564, eff. 1-1-03.
PSC 113.0812PSC 113.0812Accuracy of demand meters. In this section, “meter” or “meters” may refer to metering system(s).
PSC 113.0812(1)(1)A demand meter, demand register, or demand attachment used to measure customer’s service shall:
PSC 113.0812(1)(a)(a) Be in good mechanical and electrical condition.
PSC 113.0812(1)(b)(b) Have proper constants, indicating scale, contact device and resetting device.
PSC 113.0812(1)(c)(c) Not register at no load.
PSC 113.0812(1)(d)(d) Be accurate to the following degrees:
PSC 113.0812(1)(d)1.1. Curve drawing meters which record quantity time curves and integrated-demand meters shall be accurate to within plus or minus 2.0% of full scale throughout their working range. Timing elements measuring specific demand intervals shall be accurate to within plus or minus 2.0% and the timing elements which serve to provide a record of the time of day when the demand occurs shall be accurate to within plus or minus 4 minutes in 24 hours.
PSC 113.0812(1)(d)2.2. Lagged-demand meters shall be accurate to within plus or minus 4% of full scale at final indication.
PSC 113.0812(2)(2)The overall accuracy of demand metering installations utilizing pulse-initiator and pulse-recorder equipment shall be acceptable when the monthly kilowatt-hours calculated from the pulse count do not differ from the corresponding kilowatt-hour meter registrations by more than the kilowatt-hour constant of the meter, or 2%, whichever is greater. The timing element error shall not be more than plus or minus 4 minutes per day.
PSC 113.0812(3)(3)When a timing element also serves to keep a record of the time of day at which the demand occurs, it shall be corrected if it is found to be in error by more than plus or minus 4 minutes per day.
PSC 113.0812 HistoryHistory: Cr. Register, July, 2000, No. 535, eff. 8-1-00.
PSC 113.0813PSC 113.0813Requirements for instrument transformers.
PSC 113.0813(1)(1)Instrument transformers used in conjunction with metering equipment to measure customers’ service shall:
PSC 113.0813(1)(a)(a) Be in proper mechanical condition and have electrical insulation satisfactory for the service used.
PSC 113.0813(1)(b)(b) Be 0.3% accuracy-class units and otherwise have characteristics such that the combined inaccuracies of all transformers supplying one or more meters in a given installation will not exceed the total accuracies for the following conditions:
PSC 113.0813(1)(b)1.1. Power factor equals 1.0 and 10% load, accuracy equals 0.6%.
PSC 113.0813(1)(b)2.2. Power factor equals 1.0 and 100% load, accuracy equals 0.3%.
PSC 113.0813(1)(b)3.3. Power factor equals 0.5 and 100% load, accuracy equals 1.0%.
PSC 113.0813(2)(2)
PSC 113.0813(2)(a)(a) Meters used in conjunction with instrument transformers shall be adjusted so that the overall accuracies will come within the limits specified ss. PSC 113.0811 and 113.0812.
PSC 113.0813(2)(b)(b) Instrument transformers shall be tested with the meter with which they are associated by making an overall test, or may be checked separately. If the transformers are tested separately, the meters shall also be checked to see that the overall accuracy of the installation is within the prescribed accuracy requirements.
PSC 113.0813(2)(c)(c) The results of tests of instrument transformers shall be kept on record and available for use when transformers are installed. For other than 0.3% accuracy class instrument transformers, the results of the most recent test for each instrument transformer shall be entered on or attached to the test card form for each test of the associated meter prior to the test of that meter.
PSC 113.0813(3)(3)Phase shifting transformers shall have secondary voltages under balanced line-voltage conditions within 1% plus or minus of the voltage impressed on the primary.
PSC 113.0813 HistoryHistory: Cr. Register, July, 2000, No. 535, eff. 8-1-00.
PSC 113.0814PSC 113.0814Portable indicating instruments. All portable indicating electrical instruments used for determining quality of service to customers or for billing purposes, such as voltmeters, ammeters and watt meters, shall be checked against suitable secondary reference standards at least once in each 6 months. If the portable indicating instrument is found appreciably in error at zero or in error by more than 1% of indication at commonly used scale deflections, it shall be adjusted. A history and calibration record shall be kept for each such instrument.
PSC 113.0814 HistoryHistory: Cr. Register, July, 2000, No. 535, eff. 8-1-00.
PSC 113.0815PSC 113.0815Type of instruments. All electric service of the same type rendered under the same rate schedule shall be metered with instruments having like characteristics, except that the commission may approve the use of instruments of different types if their use does not result in unreasonable discrimination. Either all of the reactive meters which may run backwards or none of the reactive meters used for measuring reactive power under one schedule shall be ratcheted.