Related Files
Status
A final ballot for FAC-003-4 Transmission Vegetation Management is open through 8 p.m. Eastern, Monday, February 8, 2016. The voting results for the standard will be posted and announced after the ballots close. If approved, the standard will be submitted to the Board of Trustees for adoption and then filed with the appropriate regulatory authorities.
Background
In FERC Order No. 777, the Commission directed NERC to “conduct or contract testing to obtain empirical data and submit a report to the Commission providing the results of the testing.” NERC retained the Electric Power Research Institute (EPRI) to conduct testing to support appropriate Minimum Vegetation Clearance Distances (MVCDs) specified in NERC Reliability Standard FAC-003-3. The MVCDs in the Standard are calculated based on application of the Gallet equation which incorporates a gap factor. The preliminary test result findings determined that the gap factor applied in the Gallet equation requires adjustment. The resulting adjustment will increase MVCDs for all alternating current system voltages covered by Table 2 of the Standard.
Standard(s) Affected: FAC-003-3 Transmission Vegetation Management
Purpose/Industry Need
The purpose of the revised standard is to address the findings of the Electric Power Research Institute (EPRI) report, which was a part of the Federal Energy Regulatory Commission (FERC) Order No. 777 directive. The revised standard uses an updated gap factor of 1.0 in the Gallet equation to develop minimum vegetation clearance distances to decrease vegetation related events.
