R746-313. Electrical Service Reliability  


R746-313-1. Authority
Latest version.

(1) This rule establishes electric service reliability and continuity requirements as provided for in Utah Code Sections 54-3-1, 54-4-2 and 54-4-7.


R746-313-2. Definitions
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  (1) "Customer average interruption duration index" ("CAIDI") has the same meaning as in IEEE 1366 or RUS 1730A-119, as applicable.

  (2) "Electric company" means an electrical corporation or a distribution electrical cooperative that is also a public utility, as defined in Utah Code 54-2-1.

  (3) "Form 7 - Information on Service Interruptions" means:

  (a) Part G of the United States Department of Agriculture Rural Utilities Service Form 7 Financial and Statistical Report,

  (b) Part H of the National Rural Utilities Cooperative Finance Corporation Form 7 Financial and Statistical Report, or

  (c) their equivalents.

  (4) "Governing Authority" means:

  (a) for a distribution electrical cooperative as defined in Utah Code 54-2-1(6), its board of directors; and

  (b) for an electrical corporation as defined in Utah Code 54-2-1(7), the Public Service Commission of Utah, otherwise referred to as the commission.

  (5) "The Institute of Electrical and Electronics Engineers Standard 1366" ("IEEE 1366") means the 2012 edition of the IEEE Guide for Electric Power Distribution Reliability Indices.

  (6) "Loss of power supply"

  (a) "Loss of power supply - Distribution Substation" means the loss of the electrical power supply system due to an outage/failure of a distribution substation component.

  (b) "Loss of power supply - Generation/Transmission" means the loss of the electrical power supply from the electric company's own electric generator or transmission system, including transmission lines and transmission substations, or from another electric company or electric corporation.

  (7) "Momentary average interruption event frequency index" ("MAIFIe") has the same meaning as in IEEE 1366 or RUS 1730A-119, as applicable.

  (8) "Major event day identification threshold value" ("TMED") has the same meaning as in IEEE 1366 or RUS 1730A-119.

  (9) "Operating area" means a geographic subdivision of an electric company's Utah service territory that functions under the direction of an electric company office and as a separate entity used for reliability reporting within the electric company. An operating area may also be referred to as regions, divisions, or districts and may also be a reliability reporting area.

  (10) "Reliability" means the degree to which electric service is supplied without interruptions to customers.

  (11) "Reliability indices" means the electric service interruption indices identified in IEEE 1366 or RUS 1730A-119, as applicable.

  (12) "Reliability reporting area" means a grouping of one or more operating areas, for which the electric company calculates major event thresholds.

  (13) "Reporting Period" means the 12-month period, based on the previous 365 days, or 366 days for leap years, for which an electric company is tracking and reporting reliability performance.

  (14) "Rules" means the Electric Service Reliability rules R746-313-1 through 8.

  (15) "RUS 1730A-119" means the United States Department of Agriculture Rural Utilities Service Bulletin 1730A-119 entitled "Interruption Reporting and Service Continuity Objectives for Electric Distribution Systems," dated March 24, 2009.

  (16) "System average interruption duration index" ("SAIDI") has the same meaning as in IEEE 1366 or RUS 1730A-119, as applicable.

  (17) "System average interruption frequency index" ("SAIFI") has the same meaning as in IEEE 1366 or RUS 1730A-119, as applicable.

  (18) "System-wide" means pertaining to and limited to the electric company's customers in Utah.


R746-313-3. Purpose, Scope, Applicability and Exceptions
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  (1) This rule establishes requirements for each electric company to monitor and report on electric service reliability.

  (2) Unless otherwise approved, an electric company whose governing authority is the commission shall:

  (a) follow the provisions of IEEE 1366 in the collection and analysis of interruption data and in the calculation and reporting of reliability indices as required by these rules. If there is a conflict between any provision in IEEE 1366 and the rules, the rules govern; and

  (b) include both "distribution system" interruptions and "interruptions caused by events outside of the distribution system," as defined in IEEE 1366, in the electric company's record keeping, calculations, reporting, and filing as required by R746-313-4 through R746-313-8.

  (3) Unless otherwise approved, an electric company whose governing authority is not the commission shall:

  (a) follow the provisions of either IEEE 1366 or the RUS Bulletin 1730A-119 in the collection and analysis of interruption data and in the calculation and reporting of reliability indices as required by these rules. If a conflict exists between any provision in IEEE 1366 or RUS 1730A-119 and the rules, the rules govern; and

  (b) include both "distribution system" interruptions and interruptions caused by events outside of the distribution system in the electric company's record keeping, calculations, reporting, and filing as required by the Electric Service Reliability Rules R746-313-4 through R746-313-8.

  (4) The commission may, upon written request and for good cause shown, waive or modify any provision of these rules in accordance with R746-1-109, Deviation from Rules.


R746-313-4. Electric Service Reliability
Latest version.

(1) An electric company must have a written reliability program.

(2) Within 3 months after the effective date of these rules an electric company whose governing authority is the commission must file for commission approval of reliability performance baselines for SAIDI and SAIFI reliability indices.

(3) The filing required by 746-313-4(2)must include, but is not limited to:

(a) the basis for the proposed SAIDI and SAIFI values; and

(b) identification of systems and description of internal processes to collect, monitor and analyze interruption data and events including:

(i) definitions of all parameters used to calculate the proposed standards and major event days, and the time-period upon which the proposed standards are based (e.g., 12-month rolling average, 365-day rolling average, annual average);

(ii) identification of all proposed deviations from IEEE 1366 used in the calculation of reliability indices and determination of major event days; and

(iii) a description of all data estimation methods used for the collection and calculation of SAIDI, SAIFI, CAIDI, and MAIFIe.


R746-313-5. Electric Service Interruption Records
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(1) Except as provided in subsection (4) of this Section:

(a) An electric company using predominantly non-automated methods for identifying outages and tracking reliability shall keep an accurate record of each sustained interruption of service that affects one or more customers.

(b) An electric company using an electronic outage management system for identifying electric service interruptions and/or tracking outages shall keep an accurate record of each interruption of service that affects one or more customers.

(2) Each record shall contain at least the following information:

(a) the operating area where the interruption occurred;

(b) the reference identification of the substation involved;

(c) the reference identification of the circuit involved;

(d) the date and time the interruption started or was reported. If the exact time is unknown, the beginning of an interruption is recorded as the earlier of an automatic alarm or the reported initiation time;

(e) the date and time service was restored;

(f) the duration of the interruption;

(g) the number of metering points affected by the interruption;

(h) the cause of the interruption;

(i) whether the interruption was planned or unplanned;

(j) the interrupting device that made the interruption, if known; and

(k) the component involved (e.g., transmission line, substation, overhead primary main, underground primary main, transformer, etc.).

(3) For interruptions where customers are not simultaneously restored, an electric company shall keep records that document the step-restoration operations.

(4) For major events where an electric company is unable to obtain accurate data, the electric company shall make reasonable estimates and explain these estimates in any report filed with its governing authority.

(5) An electric company shall retain the records associated with this rule in accordance with R746-310-10 Preservation of Records.


R746-313-6. Inquiries about Electric Service Reliability
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(1) A customer may request a report from its electric company about the reliability of the electric service provided to the customer's own meter which the electric company must provide at no cost within 20 business days of the request. If a customer requests one or more additional reliability reports for the same meter within one year of the date of the first request, the electric company may charge the customer the cost of preparing the report(s).

(2) For an electric company whose governing authority is the commission, the report to the customer must include:

(a) The name of the customer;

(b) The date of the request;

(c) The address where the meter is installed;

(d) The meter identification number;

(e) The general identification of the equipment serving the customer; and

(f) A chronological listing of interruptions to the customer including all associated interruption data required by R746-313-5(2) covering at least the 36 months preceding the date of the request, if available. If 36 months of data are not available, the chronological listing must include all available data.

(3) For an electric company whose governing authority is not the commission, the report to the customer must include:

(a) The name of the customer;

(b) The date of the request;

(c) The address where the meter is installed;

(d) The meter identification number;

(e) The general identification of the equipment serving the customer; and

(f) A chronological listing of interruptions on the feeder serving the customer's meter including all interruption data required by R746-313-5(2) covering at least the 12 months preceding the date of the request. If 12 months of data are not available, the chronological listing must include all available data.

(4) Other than those inquiries specified in R746-313-6(1), each electric company must have a written policy for consistent treatment of all other inquiries pertaining to electric reliability. At a minimum, the electric company must provide to the inquiring party, by electronic means, the electric company's most-recently filed report on electric service reliability required by R764-313-7.


R746-313-7. Reporting on Electric Service Reliability
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(1) An electric company must report deviations from the reliability performance baselines established in accordance with R746-313-4 within 60 days after the end of the month when the deviation(s) occurred.

(2) Beginning May 1, 2013, and by May 1 of each succeeding year, an electric company shall file with the commission a report on electric service reliability for the previous calendar year. The electric company must make electronic copies of the report available to the public upon request and may charge a reasonable cost for requested paper copies.

(3) For an electric company whose governing authority is the commission, the report on electric service reliability must contain at a minimum:

(a) the calculated SAIDI, SAIFI, CAIDI, and MAIFIe reliability indices for the reporting period. At a minimum, the electric company must report this information on a system-wide basis compared with the previous four years' performance and, for SAIDI, SAIFI, and CAIDI on an operating area compared with the previous four years' performance;

(b) an analysis of the system-wide and reliability reporting area sustained interruption causes compared to the previous four-year performance. Outages may be categorized using the following cause categories:

(i) Loss of Supply - Generation/Transmission;

(ii) Loss of Supply - Distribution Substation;

(iii) Distribution - Environment (e.g., unpreventable contamination, corrosion, airborne deposits, flooding, fire/smoke not related to faults or lightning);

(iv) Distribution - Equipment Failure;

(v) Distribution - Lightning;

(vi) Distribution - Operational;

(vii) Distribution - Planned Outages;

(viii) Distribution - Public;

(ix) Distribution - Vegetation;

(x) Distribution -Weather (other than lightning);

(xi) Distribution -Wildlife;

(xii) Distribution - Unknown; and

(xiii) Distribution - Other.

(c) a listing of the major events experienced during the reporting period and a listing of significant events as defined by the electric company, their cause, and their effect on reliability performance during the reporting period;

(d) comparisons of budgeted and actual maintenance spending, maintenance activities, capital spending, vegetation management spending and vegetation management activities;

(e) identification of areas whose reliability performance warrants additional improvement efforts.

(f) a listing of the TMED values that will be used for each reliability reporting area for the forthcoming annual reporting period.

(g) a summary of the changes the electric company has made or will make pertaining to the collection, calculation, estimation, and reporting of electric service reliability information and changes in reliability reporting areas and/or operating areas; and

(h) a map showing the reliability reporting areas and/or operating areas.

(4) For an electric company whose governing authority is not the commission, the report on electric service reliability must contain, at a minimum:

(a) The reliability indices listed in Form 7 - Information on Service Interruptions based upon the cause codes listed in RUS1730A-119 ; and

(b) A summary of any estimation methods and/or an explanation of any factors used in calculating reliability indices presented in the electric company's report on electric service reliability.


R746-313-8. Major Event Reporting by Electric Utilities
Latest version.

(1) Major event reporting for an electric company whose governing authority is the commission. Within 30 business days after the conclusion of each event which an electric company determines satisfies the criteria for major event classification in accordance with IEEE 1366, the electric company shall file a major event report with the commission for its consideration. The major event report must include, at a minimum:

(a) a description of the major event, the interruption causes, and a summary of restoration efforts and factors that affected restoration of service;

(b) identification of reliability reporting area and geographic area affected;

(c) the total number of customers affected, and the number of customers without service at periodic intervals;

(d) the calculated SAIDI, SAIFI, and CAIDI impacts (i.e., Event SAIDI, SAIFI, and CAIDI) associated with the major event to customers for each reliability reporting area and system-wide; and

(e) restoration of service information including resources used and cost.

(2) Major event reporting for electric company whose governing authority is not the commission. Within a timely period after each event which an electric company determines satisfies the criteria for major event classification in accordance with IEEE 1366 or RUS 1730A-119, as applicable, the electric company shall provide a major event analysis to its governing authority.