|Transformer replaced at Wauneta substation|
|Written by Wauneta Breeze|
|Thursday, 25 September 2014 16:50|
A total of four crews were in town Sunday to switch a transformer functioning below par with a refurbished one at the Wauneta substation. Crew members pictured include Dan Sherman, Operations Manager; Dave Schmit, Substation Foreman and Chlancey Dittmer, Substation Apprentice with IES Commercial, Inc. Hidden crewmembers include Mike Mason, Project Manager/Estimator, and Steve Porter, Lineman with IES Commercial, Inc. and Ryan McClain with Doak Construction, who was operating the crane. (Sheri Hink-Wagner | The Wauneta Breeze)
By Sheri Hink-Wagner
The Wauneta Breeze
Representatives from the Village of Wauneta, IES Commercial, Inc. of Holdrege, Doak Construction of McCook and Southwest Public Power District all played a part in replacing a transformer that was performing below standards with a refurbished one at the Wauneta Substation Sunday.
Switching the two transformers resulted in a 4.5 hour planned power outage for the Village of Wauneta.
During the project, a single-phase power transformer and a single-phase voltage regulator were replaced with previously rebuilt units. According to Mike Mason with IES Commercial, Inc., outages such as this one require extensive pre-planning.
Mason explained the process required to change out the two transformers, two weeks prior to the switch Nebraska Public Power and SWPPD were notified of the upcoming power outage and NPPD prepared to issue a “clearance” on the sub-transmission line feeding the substation with power. Due to this pre-planning, when the on-site crews were ready to begin switching the transformers NPPD was able to immediately issue a “clearance” to the substation.
After the “clearance” is issued, the equipment in the substation that controls the electrical feeds to the village were opened at 1:04 p.m. MT, dropping power to the village.
Once the power was dropped in Wauneta, SWPPD opened a switch that isolated the Wauneta Substation from all incoming and outgoing power lines.
Once IES crew members verified that all required switches were visibly open, they used a voltage tester to verify that nothing within the substation was energized. For added safety, protective grounding cables were then placed strategically in the substation to protect crew members from any potential voltage on the lines.
After all these steps are taken to insure the safety of the workers, the work began. Once the electrical cables above the transformer were removed the transformer was completely removed from the system.
After Doak Construction hooked the transformer to the crane it was removed from the substation. Wauneta Village Superintendent Bill Bischoff said the rebuilt transformer weighed 18,000 pounds. Mason explained the voltage regulator is replaced in conjunction with the transformer change-out.
Using a digger/derrick truck, crew members removed the existing voltage regulator and placed the new one in the substation.
Once the new transformer was placed in the substation and electrical cables reconnected the protective grounding cables were removed and the switch for the incoming sub-transmission line was closed.
Crew members then took readings and made equipment adjustments within the substation. Then, the equipment that controls the feeds to the village were closed again and NPPD was notified the work was completed and the clearance on the substation line was released, restoring power to the village shortly after 5:30 p.m. MT Sunday.