Talk:SAIFI

I don't think the units are right here. The numerator has units of "outages" while the denominator is measured in "customers." How does outage/customer equate to hours? Can someone with a copy of the standard please check this out?

Please confirm for me if SAIFI = Number of Interruptions / Number of Customer Served

or SAIFI = Number of Customer Interrupted / Number of Customer Served

Research on December 1, 2010: SAIFI refers to the frequency of interruption, not duration, so it never comes out to hours. The index answers the question "how many times did we interrupt power to any given customer (in a given period of time - usually one year)". See SAIDI or CAIDI for duration (hours). From a utility perspective, the "number of customers served" is really the number of "service points" (meters) served, not the number of customers. A "customer" (example: xyz company or John Doe with a primary and secondary residence) may have many meters over a broad geographic area.

Regarding the reference, the wording in the article is almost an exact match to http://collaborate.nist.gov/twiki-sggrid/pub/SmartGrid/CSCTGHighLevelRequirements/Power_System_Reliability_Indices.doc, but this document is not authoritative, and does not itself provide a reference. What you really need for a reference is the governmental or industry standard that originally defined the measurement. If appears that the IEEE standard applies, but you must be a member or be willing to pay in order to see the actual standard. Here is the best citation that I could find: IEEE Std 1366-2003, IEEE guide for electric power distribution reliability indices, Transmission and Distribution Committee, IEEE Power Engineering Society, USA, 2004. It would be helpful if a member of IEEE could validate the citation.

ElecUtilityITappsTD (talk) 18:05, 1 December 2010 (UTC)

Clarification: SAIFI is based on the number of interruptions not the number of customers. If a given customer (meter) looses power 3 times in a year, all three interuptions are counted. The "S" means system, so the denominator is the number of customers (actually, meters) served, not the number who lost power.

ElecUtilityITappsTD (talk) 18:18, 1 December 2010 (UTC)

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See discussion on Talk:SAIDI. --Викидим (talk) 00:38, 17 April 2022 (UTC)