Michigan Administrative Code › Department - Licensing and Regulatory Affairs › Public Service Commission › Technical Standards for Electric Service › Part 6 - METERING EQUIPMENT INSPECTIONS AND TESTS › Section R. 460.3613a - Electro-mechanical meter and metering equipment testing requirements

Current through Vol. 24-12, July 15, 2024
Rule 613a.
(1) The
				  testing of any unit of metering equipment must consist of a comparison of its
				  accuracy with a standard of known accuracy. Units that are not properly
				  connected or that do not meet the accuracy or other requirements of these meter
				  and metering equipment rules at the time of testing must be reconnected or
				  rebuilt to meet these requirements and must be adjusted to within the required
				  accuracy and as close to zero error as practicable or must be
				  discontinued.
(2) Self-contained,
				  electro-mechanical, combination electro-mechanical and solid state,
				  single-phase, and network meters must comply with all of the following
				  requirements:
(a) Be checked for accuracy as
				  provided for in R
				  460.3602.
(b) Notwithstanding the provisions of
				  subdivision (a) of this subrule, the testing of self-contained,
				  electro-mechanical, combination electro-mechanical and solid state,
				  single-phase, and network meters in service must be governed by a quality
				  control plan that complies with all of the following:
(i) Meters must be divided into homogenous
				  groups by manufacturers" types, and certain manufacturers" types must be
				  further subdivided into separate groups by manufacturers" serial
				  numbers.
(ii) The meters in each
				  homogeneous group must then be further subdivided into lots of not less than
				  301, and not more than 35,000, meters each, except that meters of the most
				  recent design may be combined into lots regardless of manufacturers" type,
				  except that where the number of meters of a single type is 8,001 or more, that
				  number of meters must be segregated by types for the formation of
				  lots.
(iii) From each assembled
				  lot, a sample of the size specified in table A-2, ANSI/ASQ Z1.9-2003(R2018),
				  must be drawn annually. The sample must be drawn at random.
(iv) The meters in each sample must be tested
				  for accuracy pursuant to paragraphs (v) to (xi) of this subdivision.
(v) The test criteria for acceptance or
				  rejection of each lot must be based on the test at heavy load only and must be
				  that designated for double specification limits and an acceptable quality level
				  (AQL) that is not higher than 2.50 (normal inspection) as set forth in table
				  B-3, ANSI/ASQ Z1.9-2003(R2018).
(vi) The necessary calculations must be made
				  pursuant to Example B-3 of ANSI/ASQ Z1.9-2003(R2018). The upper and lower
				  specification limits, U and L, must be 102% and 98%, respectively.
(vii) A lot must be rejected if the total
				  estimated percent defective (p) exceeds the appropriate maximum allowable
				  percent defective (M) as determined from table B-3 as specified in paragraph
				  (v) of this subdivision.
(viii) All
				  meters in a rejected lot must be tested within a maximum period of 60 months
				  and be adjusted pursuant to the provisions of
				  R 460.3607 or be replaced with
				  meters that comply with the requirements of
				  R 460.3607.
(ix) During each calendar year, new meter
				  samples must be drawn as specified in this subdivision from all meters in
				  service, with the exception that lots that have been rejected must be excluded
				  from the sampling procedure until all meters included in the rejected lots have
				  been tested.
(x) The electric
				  utility or cooperative may elect to adopt the following sample plan for lots
				  that have been rejected the previous year:
(A)
				  From each rejected lot, a sample of the lot size specified in table A-2,
				  ANSI/ASQ Z1.9-2003(R2018) using general inspection level III, must be drawn at
				  random.
(B) The test criteria for
				  acceptance or rejection of each lot must be based on the test at heavy load and
				  must be that designated for double specification limits and an acceptable
				  quality level (AQL) that is not higher than 2.50 (tightened inspection) as set
				  forth in table B-3 of ANSI/ASQ Z1.9-2003(R2018).
(C) The necessary calculations must be made
				  pursuant to Example B-3 of ANSI/ASQ Z1.9-2003(R2018). The upper and lower
				  specification limits, U and L, must be 102% and 98% respectively.
(D) A lot must be rejected if the total
				  estimated percent defective (p) exceeds the appropriate maximum allowable
				  percent defective (M) as determined from table B-3 specified in paragraph (B)
				  of this subdivision. If the acceptability criteria of the sampling plan are
				  met, then the lot is considered acceptable and must be returned to the
				  variables sampling plan the following year. If the acceptability criteria of
				  the sampling plan are not met, then the electric utility or cooperative shall
				  reject that lot and all meters in that lot must be tested and adjusted or
				  replaced within a maximum period of 48 months after the second
				  rejection.
(xi) The plan
				  specified in paragraph (x) of this subdivision does not alter the rules under
				  which customers may request special tests of meters.
(c) Be checked for accuracy in both of the
				  following situations:
(i) When a meter is
				  suspected of being inaccurate or damaged.
(ii) When the accuracy of a meter is
				  questioned by a customer under
				  R 460.3601.
(d) Be inspected for mechanical and
				  electrical faults when the accuracy of the device is checked.
(e) Have the register and the internal
				  connections checked before the meter is first placed in service and when the
				  meter is repaired.
(f) Have the
				  connections to the customer's circuits checked when the meter is tested on the
				  premises or when removed for testing.
(g) A meter may not be tested or checked for
				  any reason if the device was tested, checked, and adjusted within the previous
				  12 months except when a complaint is received.