Section 170 IAC 4-1-10 - In-service tests; watthour meters, self-containedAuthority: IC 8-1-1-3; IC 8-1-2-4
Affected: IC 8-1-2-35
Sec. 10.
(a) A utility may adopt either Method A as described in subsection (b) or Method B as described in subsection (c) for maintaining the accuracy of self-contained meters without attachments or with frictionless attachments.(b) For Method A, periodic testing of watthour meters, each public utility shall, after the adoption of this rule, use not more than a sixteen (16) year schedule of periodic testing.(c) For Method B, quality control testing of watthour meters, a public utility may adopt the following quality control testing method for self-contained watthour meters, in service, on written notice to the commission:(1) Meters shall be divided into homogenous groups.(2) The meters in each group may be further subdivided into lots; however, no lot size shall be less than three hundred one (301) meters.(3) From each lot there shall be drawn annually a number of meters to be tested as specified in Table A-2, ANSI/ASQC Standard Z1.9, dated 1993, using Inspection Level II. Due care shall be exercised that the meters to be tested shall be drawn at random, and all such meters shall be tested for accuracy.(4) The test criterion for acceptance or rejection of each lot shall be based on the test at full load only and shall be that designated for Double Specification Limit-Variability Unknown-Standard Deviation Method at the 2.50 Acceptable Quality Level (normal inspection) as shown in Table B-3, ANSI/ASQC Standard Z1.9, dated 1993.(5) The necessary calculations shall be made in accordance with the illustration (Example B-3), ANSI/ASQC Standard Z1.9, dated 1993. The upper and lower accuracy specification limits, U and L, shall be one hundred two percent (102%) and ninety-eight percent (98%), respectively.(6) A lot shall be rejected if the total estimated percent defective (p) exceeds the appropriate maximum allowable percent defective (m) as determined from Table B-3, ANSI/ASQC Standard Z1.9, dated 1993.(7) Meters in a rejected lot shall be subject to an accelerated test schedule to be completed within a maximum period of ninety-six (96) months and shall comply with section 9 of this rule, or shall be retired from service. Such accelerated testing of a rejected lot may be discontinued when the subsequent test results show that the lot is within acceptable limits of accuracy.(8) A public utility, operating under this optional testing plan, may elect to test the meters included in any group or lot on a test schedule of not more than sixteen (16) years subject to section 9 of this rule.(9) Each public utility shall keep all necessary records to enable the commission to check procedures followed, tests made, and calibrations employed in conformance with this optional testing method.(10) All provisions of the aforesaid ANSI/ASQC Standard Z1.9, dated 1993, explanatory of or essential to the application of Table A-2, Table B-3, and Example B-3, as referenced in subdivisions (3) through (5), are hereby incorporated in this rule by reference.(d) Requirements for other watthour meters are as follows:(1) Electromechanical watthour meters with surge proof magnets and the following: (A) Mechanical KWH registers shall be tested at least every sixteen (16) years.(B) Mechanical demand registers shall be tested at least every eight (8) years.(C) Electronic demand registers shall be tested at least every sixteen (16) years.(D) Mechanical cam pulse initiators shall be tested at least every two (2) years.(E) Mechanical gear shutter pulse initiators shall be tested at least every eight (8) years.(F) Electronic pulse initiators shall be tested at least every twelve (12) years.(G) Electronic registers, for example, TOU or recorder, shall be tested at least every sixteen (16) years.(H) Thermal demand registers shall be tested at least every eight (8) years.(2) Electronic meters shall be tested at least every sixteen (16) years.Indiana Utility Regulatory Commission; No. 33629: Standards of Service For Electrical Utilities Rule 10; filed Mar 10, 1976, 9:10 a.m.: Rules and Regs. 1977, p. 342; filed Feb 23, 1998, 11:30 a.m.: 21 IR 2324; readopted filed Jul 11, 2001, 4:30 p.m.: 24 IR 4233; readopted filed Apr 24, 2007, 8:21 a.m.: 20070509-IR-170070147RFA; readopted filed Aug 2, 2013, 2:16 p.m.: 20130828-IR-170130227RFAReadopted filed 4/11/2019, 9:04 a.m.: 20190508-IR-170190136RFA