Chapter PSC 113

PSC 113.0904 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0905 PSC 113.0905 Methods of testing watthour meters.

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) (3) Polyphase meters shall be tested by one of the following 4 methods:

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 113.0905 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0906 PSC 113.0906 Methods of testing block-interval demand registers.

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 113.0906 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0907 PSC 113.0907 Methods of testing block-interval pulse-operated demand meters and pulse recorders.

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 113.0907 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0908 PSC 113.0908 Methods of testing electronic (solid state) meters.

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 113.0908(2) (2) Electronic meters designed to operate over an extended voltage range may be tested at a single test voltage point to determine meter accuracy.

PSC 113.0908 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0909 PSC 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.

PSC 113.0909 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0910 PSC 113.0910 Methods of testing electronic demand registers. Electronic demand registers shall be tested or checked for accuracy. The operation and accuracy of the timing circuit shall be verified. The accuracy must meet manufacturer’s published specifications. The register shall also be checked to verify that the program resets the demand period at the end of the testing demand interval.

PSC 113.0910 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0911 PSC 113.0911 Testing of self-contained single-phase meters and 3-wire network meters at fixed periodic intervals. In this section, “meter” or “meters” may refer to metering system(s).

PSC 113.0911(1) (1) Self-contained single-phase meters and 3-wire network meters, together with associated equipment such as demand devices, control devices, etc., shall be tested for accuracy at unity power factor at the point where they are installed or at a central testing point or in a mobile testing laboratory under any of the following circumstances:

PSC 113.0911(1)(a) (a) Before being placed in service. For new meters given a prior test by the manufacturer, a sample test program meeting the requirements of s. PSC 113.0920 or use of the manufacturer’s certified test results for all meters tested under the provisions of s. PSC 113.0921, may be substituted for this requirement.

PSC 113.0911(1)(b) (b) When they are suspected of being inaccurate or damaged.

PSC 113.0911(1)(c) (c) When the accuracy is questioned by a customer. See s. PSC 113.0922.

PSC 113.0911(1)(d) (d) When they are removed from service.

PSC 113.0911(1)(e) (e) Within a period of 6 months before to 6 months after 5 years of service for non-magnetic-bearing meters and 20 years of service for magnetic-bearing surge-proof meters or in accordance with the plan outlined in s. PSC 113.0921.

PSC 113.0911 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0912 PSC 113.0912 Testing of self-contained polyphase meters. In this section, “meter” or “meters” may refer to metering system(s).

PSC 113.0912(1) (1) Self-contained polyphase meters together with associated equipment such as demand equipment, control devices, etc., shall be tested on the customer’s premises, a central testing facility or in a mobile test facility, except pars. (a) and (d), for accuracy at unity and 50% power factor under the following circumstances:

PSC 113.0912(1)(a) (a) Before being placed in service. For new meters given a prior test by the manufacturer, the manufacturer’s certified test results may be substituted for this requirement.

PSC 113.0912(1)(b) (b) When they are suspected of being inaccurate or damaged.

PSC 113.0912(1)(c) (c) When the accuracy is questioned by a customer. (See s. PSC 113.0922.)

PSC 113.0912(1)(d) (d) Within 60 days after they are removed from service.

PSC 113.0912(1)(e) (e) Within a period of 6 months before or 6 months after 8 years of service for non-surge-proof and 12 years for surge-proof meters. Exception: Thermal and mechanical lagged-demand meters shall be tested every 8 years. Electronic (solid state) meters may be tested instead in accordance with the plan outlined in s. PSC 113.0921.

PSC 113.0912(2) (2) A stator balance test shall be performed on all new meters before being placed in service.

PSC 113.0912(3) (3) Meters with electronic programmable registers may be shop tested on a periodic basis.

PSC 113.0912 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00; CR 02-027: am. (1) (intro.) and (a), Register December 2002 No. 564, eff. 1-1-03.

PSC 113.0913 PSC 113.0913 Testing of meters used with instrument transformers on single-phase service. In this section, “meter” or “meters” may refer to metering system(s).

PSC 113.0913(1) (1) Meters used with instrument transformers on single-phase service, together with associated equipment such as demand equipment, control devices, etc., shall be tested on the customer’s premises, a central testing facility or in a mobile test facility, except pars. (a) and (d), for accuracy at unity power factor under the following circumstances:

PSC 113.0913(1)(a) (a) Before being placed in service. For new meters given a prior test by the manufacturer, the manufacturer’s certified test results may be substituted for this requirement.

PSC 113.0913(1)(b) (b) When they are suspected of being inaccurate or damaged.

PSC 113.0913(1)(c) (c) When the accuracy is questioned by a customer. (See s. PSC 113.0922.)

PSC 113.0913(1)(d) (d) When they are removed from service.

PSC 113.0913(1)(e) (e) Within a period of 6 months before or 6 months after 8 years of service for non-surge-proof and 12 years for surge-proof meters. Exception: Lagged-demand meters shall be tested every 8 years. Electronic (solid state) meters may be tested instead in accordance with the plan outlined in s. PSC 113.0921.

PSC 113.0913(2) (2) Meters equipped with electronic programmable registers may be shop tested on a periodic basis.

PSC 113.0913 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00; CR 02-027: am. (1) (intro.) and (a), Register December 2002 No. 564, eff. 1-1-03.

PSC 113.0914 PSC 113.0914 Testing of polyphase electromechanical and completely solid state electronic meters used with instrument transformers at fixed periodic intervals. In this section, “meter” or “meters” may refer to metering system(s).

PSC 113.0914(1) (1) Polyphase meters used with instrument transformers, together with associated equipment such as demand equipment, pulsing devices, phase-shifting transformers, control devices, etc., shall be tested on the customer’s premises, a central testing facility or in a mobile test facility, except for pars. (a) and (d), for accuracy at unity and 50% power factor under the following circumstances.

PSC 113.0914(1)(a) (a) Before being placed in service. For new meters given a prior test by the manufacturer, the manufacturer’s certified test results may be substituted for this requirement.

PSC 113.0914(1)(b) (b) When they are suspected of being inaccurate or damaged.

PSC 113.0914(1)(c) (c) When the accuracy is questioned by a customer. (See s. PSC 113.0922.)

PSC 113.0914(1)(d) (d) When they are removed from service.

PSC 113.0914(1)(e) (e) Within a period of 4 months before or 4 months after 2 years of service for non-magnetic-bearing electromechanical meters, 4 years of service for electromechanical magnetic-bearing surge-proof meters and 6 years of service for completely solid state electronic meters with electronic registers capable of down-loading voltage and current monitoring readings from the instrument transformers to digital meter reading devices at meter reading intervals. Exception: Electronic (solid state) meters may be tested instead in accordance with the plan outlined in s. PSC 113.0921.

PSC 113.0914(2) (2) A stator balance test shall be performed on all new meters before being placed in service.

PSC 113.0914(3) (3) Meters with electronic programmable registers may be shop tested on a periodic basis.

PSC 113.0914 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00; CR 02-027: am. (1) (intro.) and (a), Register December 2002 No. 564, eff. 1-1-03.

PSC 113.0915 PSC 113.0915 Testing of metering installations utilizing pulse devices.

PSC 113.0915(1) (1) Metering installations utilizing pulse initiators and pulse recorders shall be checked for accuracy each billing period by comparing the recorded pulse count against the registration of the corresponding meter. When the results are not in agreement within the accuracy limits of s. PSC 113.0812 (2) the pulse devices shall be promptly tested and adjusted to required accuracy or replaced.

PSC 113.0915(2) (2) Pulse devices shall be tested before use and as part of the complete metering installation whenever the associated watthour meter is tested.

PSC 113.0915 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0916 PSC 113.0916 Testing of instrument transformers.

PSC 113.0916(1) (1) No instrument transformer shall be placed in service, or allowed to remain in service, if it shows evidence of physical damage, discolored terminals due to overload, change in texture or resiliency of insulation, or arc tracking on the insulation or bushings.

PSC 113.0916(2) (2) Instrument transformers of all utilities shall be tested for voltage withstand by the manufacturer, the utility, or a laboratory approved for such test by the commission before being placed in service. Each instrument transformer that has been removed from service shall be tested for voltage withstand prior to reinstallation if the reason for removal or physical appearance, gives cause to doubt its reliability. The utility shall maintain a record of all such tests.

PSC 113.0916(3) (3) Instrument transformers of class A privately-owned utilities shall be tested at the utility meter shop or the manufacturers’ certified test reports may be used to determine accuracy (ratio correction factor and phase angle):

PSC 113.0916(3)(a) (a) Before being initially placed in service.

PSC 113.0916(3)(b) (b) When removed from service.

PSC 113.0916(3)(c) (c) When there is evidence from outward appearance or performance to suspect inaccuracy.

PSC 113.0916(3)(d) (d) The manufacturer’s calibration results may be acceptable on all new voltage transformers rated above 15,000 volts. Removal tests of these transformers may also be omitted except in those cases where there is reason to suspect that a transformer malfunction has occurred.

PSC 113.0916(4) (4) Instrument transformers of other than class A private-owned utilities shall be tested at the utilities meter shop, the manufacturer’s laboratory or a laboratory approved by the commission for accuracy (ratio correction factor and phase angle):

PSC 113.0916(4)(a) (a) Before being initially placed in service.

PSC 113.0916(4)(b) (b) When there is evidence from outward appearance or performance to suspect inaccuracy.

PSC 113.0916(5) (5) Instrument transformers in service shall be given an approved check (such as the variable burden method in the case of current transformers or a field check of the secondary voltage with a good quality voltmeter in the case of voltage transformers) made in conjunction with each field test of the associated watthour meter. When such check provides evidence that the instrument transformer may be inaccurate, that instrument transformer shall be tested for accuracy.

PSC 113.0916 History History: Cr. Register, July, 2000, No. 535, eff. 8-1-00.

PSC 113.0917 PSC 113.0917 Phase-shifting transformers and loss compensators.

PSC 113.0917(1) (1) For phase-shifting transformers in service, all terminal connections shall be in such condition as to provide good electrical contact and the terminal designations shall be clearly visible. Where there is evidence of physical damage or evidence of thermal overload the unit shall be replaced.

PSC 113.0917(2) (2) Phase-shifting transformers shall be tested on the same schedule and at the same time as the meters with which they are associated. The test shall consist of a single-phase test to be performed as follows: With the approximate rated voltage applied to the input terminals and no burdens connected to the tap terminals all tap voltages, converted to percentage of input voltage, shall agree within plus or minus 2.0% of the theoretical values given in the manufacturer’s published data.

PSC 113.0917(3) (3) In addition, all units shall be tested before use and when returned to the utility’s meter laboratory. For these tests the output-voltage values in terms of percentage of input voltage and under the conditions of sub. (2) immediately above shall agree within plus or minus 1.0%.

PSC 113.0917(4) (4) For transformer-loss compensators in service all terminal connections shall be in such condition as to provide good electrical contact and the terminal designations shall be clearly visible. Where there is evidence of physical damage to the component parts, their adjustments, or to the internal wiring or evidence of thermal overload on the insulation, resistors, terminals, etc., the affected parts shall be replaced or the entire transformer-loss compensator replaced.

PSC 113.0917(5) (5) Transformer-loss compensators shall be tested on the same schedule and at the same time as the meters with which they are associated.

PSC 113.0917(6) (6) The tests shall be made at the normal service test points of the meter. Performance deviations from desired performance shall not exceed plus or minus 0.3%.