OAR 860-023-0081: Definitions and Terms for Electric Service Reliability

(1) Effective beginning January 1, 2012, the definitions in IEEE 1366, as defined in subsection (2)(b) of this rule, are adopted unless otherwise expressly modified by this rule. If there is a conflict between the definitions in IEEE 1366 and this rule, the definitions in this rule govern. (2) The following definitions apply to the Electric Service Reliability Rules, OAR 860-023-0081 through 860-023-0161: (a) "Electric company" means a public utility, as defined in ORS 757.005, that supplies electricity. (b) “IEEE 1366” means the Institute of Electrical Electronic Engineers (IEEE) Standard 1366 entitled “IEEE Guide for Electric Power Distribution Reliability Indices” (the 2012 edition), approved on May 14, 2012 by IEEE-SA Standards Board. (c) “Loss of Supply — Substation” or “Power Supply — Substation” means an interruption cause category related to an outage of a distribution substation component. (d) “Loss of Supply — Transmission” or “Power Supply — Transmission” means an interruption cause category related to the interruption of the electrical supply by the electric company’s transmission system or by another electrical utility or operator. (e) “Reliability reporting area” means a grouping of one or more operating areas, for which the electric company calculates major event thresholds. (f) “Reporting Period” means the 12-month period, based on a calendar year, for which the electric company is reporting reliability performance. (g) "System-wide" means pertaining to and limited to the electric company's customers in Oregon. (3) For reference only, some IEEE 1366 acronyms or terms commonly used in OAR 860-023-0081 through 860-023-0161 are repeated herein. (Note - refer to exact definitions and calculation methodologies in IEEE 1366.) (a) "CAIDI" means customer average interruption duration index. (b) “Customer” means a metered electrical service point for which an active bill account is established at a specific location (e.g., premise). (c) “Interruption” means the loss of service to one or more customers connected to the distribution portion of the system. It is the result of one or more component outages, depending on system configuration. (d) "MAIFIE" means momentary average interruption event frequency index. (Note -This index does not include events immediately preceding a lockout.) (e) “SAIDI" means system average interruption duration index. (f) “SAIFI" means system average interruption frequency index. (g) “Major Event” designates an event that exceeds the reasonable design and or operational limits of the electric power system. A major event includes at least one Major Event Day (MED). (h) “Major Event Day” or “MED” means a day in which the daily system SAIDI exceeds a threshold value, TMED. For the purposes of calculating daily system SAIDI, any interruption that spans multiple calendar days is accrued to the day on which the interruption began. Statistically, days having a daily system SAIDI greater than TMED are days on which the energy delivery system experienced stresses beyond that normally expected (such as severe weather). Activities that occur on major event days should be separately analyzed and reported. (i) “TMED” means a major event day identification threshold value. [Publications: Publications referenced in this rule are available for review at the agency.]