Reliability Standard: PRC-008-0
Requirement: 1
Region: SPP
Issue: SPP conducted a compliance audit on June 27, 2011, during which it found that Malden violated R1 of PRC-008-0 in that it failed to have an Under Frequency Load Shedding (UFLS) equipment maintenance and testing program that show the UFLS equipment or the UFLS equipment testing and maintenance schedule before April 4, 2011. Furthermore, after April 4, 2011, Malden didn't include the potential transformer (PT) that works with its only under-frequency relay.
Finding: SPP found that the issue posed a minimal risk to the reliability of the bulk power system since Malden was able to demonstrate that it had been conducting tests on its UFLS protection system not beyond the manufacturer's recommended testing intervals, thus making it less likely to harm the BPS. Therefore, SPP found the issue to be one of documentation. Furthermore, Malden only has assets connected 100kV or below, with its load being served by a 69kV connection with another entity, had a summer peak load of 13.3MW, and possesses one UFLS relay.
Dairyland Power Cooperative (DPC), Docket No. RC13-8, April 30, 2013
Reliability Standard: PRC-008-0
Requirement: 2
Region: MRO
Issue: While conducting a Compliance Audit in March 2011, MRO found that DPC, a DP and TO, had not tested one station battery in 2009, accounting for approximately 1% of all devices, in accordance with the schedule established in its Under Frequency Load Shedding (UFLS) equipment maintenance and testing program. As such, it could not provide the results to that test upon request and as required by PRC-008-0 R2.
Finding: The violation was deemed to pose minimal risk to BPS reliability but not serious or substantial risk which was mitigated because each month cell and battery voltage was checked, and each year cell and battery impedance was checked. No issues were found upon testing. Also, had the battery been unavailable, DPC would have been able to meet its load obligation.
Delmarva Power & Light Company (Delmarva), FERC Docket No. RC13-3-000 (December 31, 2012)
Reliability Standard: PRC-008-0
Requirement: 2
Region: RFC
Issue: Delmarva self-reported a violation of R2 of PRC-008-0 to RFC on September 18, 2012, regarding the failure of maintaining test results to show that it tested a distribution microprocessor relay with an under frequency load shedding (UFLS) scheme within the time frame mandated by PRC-008-0 Protective System Schemes Protection and Maintenance Program & Procedures (Procedures). The particular issue involved Delmarva's failure to test the relay again before December 21, 2011, as required by the Procedures. Furthermore, Delmarva could not show the test results for March 4, 2007 trip test.
Finding: RFC found this issue to be a minimal risk to the reliability of the bulk power system since the relay that Delmarva failed to test is less than 1% of its UFLS equipment. Without this delay, Delmarva would be able to satisfy the required load shedding had it undergone an under frequency excursion, and also would be able to shed 13.7% of its estimated annual peak load, more than the 10% required by the UFLS program. If the relay went through a false trip, it would only trip one distribution circuit with 20 MW of the peak load. Furthermore, the self-monitoring microprocessor relay is designed to alert operators in case of failure, but during the time period, did not produce any alerts. Moreover, the relay functioned within expectation during the time period as confirmed by the health check before the trip test. During the time period, there was neither a frequency false trip nor a system under frequency event. Since this was an isolated event found while performing a compliance activity pursuant to its Procedure, RFC determined the issue to be a minimal risk.
Find, Fix and Track Entity, Docket No. RC11-6 (September 30, 2011)
Reliability Standard: PRC-008-0
Requirement: R1
Region: FRCC
Issue: FFT Entity self-reported that it had not implemented a maintenance and testing program for its UFLS relays.
Finding: FRCC found that this issue constituted only a minimal risk to BPS reliability since FFT Entity was actually conducting some maintenance and testing on the UFLS relays (even though it was not being properly documented). FFT Entity is also a very small entity.
Find, Fix and Track Entity, Docket No. RC11-6 (September 30, 2011)
Reliability Standard: PRC-008-0
Requirement: R1, R2
Region: MRO
Issue: During a compliance audit, MRO determined the FFT Entity did not identify all UFLS equipment in its UFLS equipment maintenance and testing program. Specifically, the program did not identify UFLS station batteries, DC control circuitry, and frequency sensing devices in violation of R1. FFT Entity was in violation of R2 because it failed to provide evidence of weekly pilot cell voltage and specific gravity readings or the annual cell voltage, cell impedance or stop resistance testing of its station batteries used in its UFLS program. The violation encompassed two station batteries, or approximately 9.5% of its UFLS devices.
Finding: MRO found that this issue constituted only a minimal risk to bulk power system reliability because the FFT Entity only has two interconnection points and will only shed 23 MW of UFLS load.
Find, Fix and Track Entity, Docket No. RC11-6 (September 30, 2011)
Reliability Standard: PRC-008-0
Requirement: R1, R2
Region: SERC
Issue: Following a self-report, SERC determined FFT Entity violated R1 because it did not have a written procedure addressing UFLS equipment identification and a schedule for UFLS equipment testing and maintenance. During a compliance audit, SERC determined the FFT Entity violated R2 because it could not produce evidence that the under frequency element of the electronic re-closer control relays had been tested.
Finding: SERC found that this issue constituted only a minimal risk to bulk power system reliability because the FFT Entity’s TO/TOP has its own protective relaying, and FFT Entity owns protective relaying to protect its own equipment on its side of the delivery point. Therefore, it is unlikely that an event occurring on FFT Entity’s system would affect the BPS. In addition, FFT Entity is a minimal size utility.
Find, Fix and Track Entity, Docket No. RC11-6 (September 30, 2011)
Reliability Standard: PRC-008-0
Requirement: R2
Region: MRO
Issue: FFT Entity self-reported that it had not fully implemented its UFLS maintenance and testing programs as it did not conduct the required testing for 10 devices (out of 68).
Finding: MRO found that this issue constituted only a minimal risk to BPS reliability since, in a worst case scenario, FFT Entity’s UFLS equipment would only have had an 80 MW impact for load shed. In addition, once tested, the relevant UFLS devices were found to be in satisfactory condition.
Find, Fix and Track Entity, FERC Docket No. RC12-1 (October 31, 2011)
Reliability Standard: PRC-008-0
Requirement: R2
Region: MRO
Issue: During a compliance audit, MRO determined that FFT Entity did not possess all of the required maintenance and testing records for 33 of its UFLS relays, 5 of its UFLS station batteries, 79 of its voltage and current sensing devices, 24 of its station batteries, and 33 of its DC control circuits.
Finding: MRO found that the issue constituted a minimal risk to BPS reliability. Only 17% of the total UFLS load shed for which FFT Entity is responsible for would be affected by problems with the 5 relevant UFLS station batteries. And when the relevant devices were tested, no issues were discovered. In addition, FFT Entity is always monitoring, via SCADA, the DC power supply to the UFLS devices.
Greenwood Utilities Commission (Greenwood), Docket No. RC12-14 (July 30, 2012)
Reliability Standard: PRC-008-0
Requirement: 2
Region: SERC
Issue: While conducting a compliance audit, the SERC audit team found that Greenwood had not tested 10 out of 17 (or 59%) Under Frequency Load Shedding (UFLS) relays within the time required by Greenwood’s UFLS maintenance and testing program. Greenwood reported that it missed testing because it was in the start-up process to a new substation and the contractors were working on testing those UFLS relays.
Finding: The issue was deemed by SERC to pose minimal risk to BPS reliability because the ATCID was revised to include the required information and the models connected with this ATCID were shown to be complete.
Metropolitan Edison Company (MetEd), Docket No. RC13-9, May 30, 2013
Reliability Standard: PRC-008-0
Requirement: 2
Region: RFC
Issue: Further to a Compliance Audit, RFC determined that MetEd, as a DP and TO, had an issue with PRC-008-0 R2 because Met Ed could not provide Under Frequency Load Shedding (UFLS) program results for three UFLS relays. Specifically, MetEd could not provide the results of the maintenance and testing that corresponded to its database maintenance and testing records for its Fairview, Hokes, and Walker UFLS relays.
Finding: RFC determined that the issue posed a minimal risk to the reliability of the BPS because this was merely a documentation issue. In addition, MetEd was able to provide maintenance and testing dates as well as UFLS program results for all other UFLS relays when requested during the Audit, and the most recent maintenance and testing dates for the three UFLS relays at issue were within the five-year UFLS maintenance and testing interval.
North Carolina Eastern Municipal Power Agency (NCEMPA), Docket No. RC12-13 (June 29, 2012)
Reliability Standard: PRC-008-0
Requirement: R1
Region: SERC
Issue: NCEMPA is a DP and is registered as a JRO on behalf of 15 municipalities, including the City of Washington, NC (City), a participant in Progress Energy Carolina’s (PEC) Under Frequency Load Shedding (UFLS) program. On August 26, 2011, NCEMPA submitted a self-report stating that UFLS program used by the City did not include the underfrequency functionality. The issue came to light upon NCEMPA’s implementation of a new UFLS equipment and testing program to replace the differing UFLS programs used by its members. The City reported to NCEMPA that the program it had been using included functional relay testing for UFLS relays, but it did not contain provisions for testing of the relays’ underfrequency capability. SERC review determined that the UFLS program used by the City did contain a maintenance and testing schedule, but it did not have the list of equipment required by R1 of PRC-008-0. SERC noted that the other member municipalities using PEC’s UFLS program had submitted the required equipment list. NCEMPA has 87 UFLS relays of which nine (or 10.3% of all NCEMPA’s UFLS relays) were not included on the City’s equipment list in its UFLS equipment maintenance and testing procedure.
Finding: The issued was deemed by SERC to pose minimal risk to BPS reliability as the 40 relays were tested and found to be functional and Ameren had backup protection provisions in the event of a relay failure. The two station batteries were also tested with no problems reported. The batteries were also alarmed to notify personnel to any failure and were less than 10 years old.
Northern Indiana Public Service Company (NIPSCO), Docket No. RC13-10, June 27, 2013
Reliability Standard: PRC-008-0
Requirement: R2
Region: RFC
Issue: NIPSCO, as a TO, self-reported an issue with PRC-008-0 R2 to RFC when it found that a six-year maintenance and testing interval, rather than a two-year interval required by its Under Frequency Load Shedding (UFLS) program had been entered into its relay tracking system database for eight UFLS relays. Due to this error, the TO failed to test or maintain eight of 167 UFLS relays within the two-year interval.
Finding: RFC determined that the issue posed a minimal risk to the reliability of the BPS because relays at issue are microprocessor-based and perform self-testing and alarming. They are also monitored through NIPSCO’s distribution management system, and upon performing maintenance and testing, NIPSCO found that the relays were set properly and would have responded correctly to an under frequency event.
Oklahoma Municipal Power Authority (OMPA), Docket No. RC13-6-000 (February 28, 2013)
Reliability Standard: PRC-008-0
Requirement: 2/2.1/2.2
Region: SPP RE
Issue: OMPA submitted a self-report in November 2012 explaining that, as a DP, it had not tested 7 of 42 (16.67%) Under Frequency Load Shedding (UFLS) relays within the three-year timeframe established in its Protection and Control procedures. One had been removed from service; one was unable to be taken out of service for testing due to the amount of load on the substation during the testing period; and the other five were missed due to a scheduling error by OMPA's testing consultants.
Finding: The issue was deemed to pose minimal risk to BPS reliability and not serious or substantial risk. The risk to BPS operations was mitigated because of the small amount of relays involved and that five were tested only one month out of time and two were tested within a year of the due date, which was still earlier than NERC's 10-year testing interval recommendation.
Piggott Light & Water (Piggott), Docket No. RC13-7-000 (March 27, 2013)
Reliability Standard: PRC-008-0
Requirement: 2
Region: SPP RE
Issue: While conducting a compliance audit, SPP RE found an issue with PRC-008-0 in that Piggott, a registered Distribution Provider, had not updated its Under Frequency Load Shedding (UFLS) relay settings after an October 2007 update to its UFLS program. In October 2007, Piggott added three distribution load shed points – i.e., UFLS relays at three locations – available to respond to underfrequency events to its UFLS Relay Testing and Battery Maintenance/Inspection Program, but the three relays were not tested at the time to ensure they would initiate a breaker trip at the appropriate frequencies. In March 2012, Piggott discovered that, although the change had been made to its UFLS program, changes had not been made to the settings of the three relays, and so its UFLS program was operating under the program prior to the October 2007 update. Once discovered, Piggott revised its relay settings to include the loads identified with the three distribution circuits; however, the relays were eventually found to have been set to trip below the SPP UFLS plan's requirements. After July 19, 2012, Piggott tested and set the relays at the appropriate level.
Finding: The issue was deemed to pose minimal risk to BPS reliability and not serious or substantial risk because the two relays associated with the pre-October 2007 UFLS program were maintained and tested pursuant to required intervals and would have performed according to the SPP UFLS plan. Once the three relays had been set to automatically trip, although incorrectly set, it was determined that Piggott's system would have been able to shed all required load if a load shedding event had occurred. Also, the time involved with the incorrect set points was limited to only a four-month period.
Town of Sharpsburg (Sharpsburg), Docket No. RC12-12 (May 30, 2012)
Reliability Standard: PRC-008-0
Requirement: R1
Region: SERC
Issue: Sharpsburg, in its role as a DP, submitted a self-report detailing that it was in violation of the Standard because it had no documented underfrequency load shedding (UFLS) testing program in place before March 2011.
Finding: The issue was found to pose minimal risk to BPS reliability because even though Sharpsburg did not have a formally document UFLS program until March 11, 2011, the UFLS relay was being tested. And, the size of the Sharpsburg facility and the fact that Sharpsburg does not own any BPS facilities lessened any risk to BPS operations.
Virginia Electric and Power Company (VEPCO-Trans), Docket No. RC13-9, May 30, 2013
Reliability Standard: PRC-008-0
Requirement: 2
Region: SERC
Issue: VEPCO-Trans, as a DP and TO, self-reported an issue with PRC-008-0 R2 to SERC after finding that six Under Frequency Load Shedding (UFLS) relays were tested outside of the defined interval and that VEPCO-Trans was unable to produce the field record maintenance and testing documentation for six other UFLS relays.
Finding: SERC determined that the issue posed a minimal risk to the reliability of the BPS because the three stations (corresponding to the six UFLS relays) at issue totaled 230 MW and if VEPCO-Trans were to exclude these locations, it would have a load shed of 5,266.3 MW (30.20%), which is still in excess of the 30% required by the regional criteria. Furthermore, when the relays were tested, they were found to be functioning properly, and even if they had not functioned properly in the event of a UFLS event, the 30% load shed value requirement would have still been met.
