Substation equipment changed out during planned outage for City of Rushford
Cresco, IA | Rushford, MN (11:30 a.m. Dec. 19, 2017)— On Monday, shortly before midnight, crews from Dairyland Power Cooperative, ITC Midwest and MiEnergy Cooperative were at the City of Rushford’s substation to replace lightning arrestors and fuses.
Earlier in the day, an investigation of the substation by MiEnergy with an infrared camera showed a hot spot on an arrestor. The data was confirmed by Dairyland and both cooperatives were confident that Saturday’s electric blinks could be related to this equipment issue. The cooperatives acted immediately in an effort to alleviate the possibility of future blinks. As it is in most cases, the cooperatives chose an overnight planned outage as it typically affects less businesses.
Dairyland changed out three lightning arrestors and fuses on the high side of the transformer within the substation and MiEnergy changed out three arrestors on the low side of the transformer. Lightning arrestors are designed to protect substation equipment.
“When changing out the arrestors and fuses, the suspect arrestor did show signs of degradation with burn marks on the steel base it was mounted to,” said Brian Krambeer, MiEnergy president/CEO. “Based on what they saw Monday night, we are hopeful the problem has been found and corrected.”
The overall outage was approximately two hours, which was an hour longer than expected due to a fuse mount that was found bent.
In the meantime, fault indicators on ITC’s transmission line will continue to be in place should another fault occur it will help pinpoint the location.
MiEnergy, ITC Midwest and Dairyland thank everyone for their patience during this frustrating series of blink events.
The blinks on Saturday were felt by the cities of Lewiston, Utica, Rushford and Stockton and the rural areas surrounding those cities. Saturday’s blinks were a separate issue from the ones experienced two weeks ago when ITC Midwest changed out insulators on a stretch of transmission line north of Rushford. Fault indicators showed Saturday’s blinks in the area between Good Shepherd Nursing Home and the City of Rushford’s substation.