Photos by Jack Murray
The ongoing pandemic has had a necessary effect on the specific ways in which WAPA accomplishes its mission, but the need for reliable, affordable hydroelectricity continues. The organization’s work of upgrading and maintaining the grid remains a top priority.
Crews in Desert Southwest demonstrated this commitment with recent work at Mead Substation in Nevada. The first week of April saw the start of a large-scale 230/500-kilovolt transformer rebuild project, which is expected to take around one month to complete.
“When the year began, it wasn’t our initial plan to rebuild it,” said Vice President of Transmission System Asset Management Jack Murray. “As maintenance was performed, however, issues were discovered that caused major concern.”
Needless to say, the transformer was immediately and comprehensively tested in order to assess its reliability.
“After thorough testing, it was determined that we could have put the transformer back into service with just the planned maintenance,” said Murray. “But that was not something we were comfortable with. The risk for catastrophic failure of the transformer during the peak summer season was too great. Reliability is paramount. We decided to move forward with replacement.”
Transformer replacements are big jobs. In the case of Mead Substation, the crew working on the project consisted of around 10 craft employees. The replacement involved the use of cranes and bucket trucks to move and handle the components of the transformer. For example, just one of the 500-kV bushings weighs around two and a half tons.
It’s not just the weight of the components that makes things difficult; there’s also the fragility.
“Interesting factoid,” Murray said, “the bushings are ceramic-coated, so installation of this behemoth requires finesse and care to avoid chipping or breaking any of the ceramic.”
Removing and installing bushings requires careful coordination between the crane operator, the crew member in the lift, two crew members atop the transformer and two crew members inside the transformer, all of whom focus intently on guiding it into a relatively tight space without damaging it or anything else.
Of course, multiple employees sharing close quarters like this is not normally advisable or acceptable during a pandemic, but crews exercised the necessary precautions. Employees working fewer than six feet apart wore body suits and masks to ensure their personal safety.
One upcoming phase of the transformer replacement involves removing each of the nine radiators, relocating them and replacing gaskets, seals and other components in need of maintenance before reinstalling them.
“The entire crew worked like crazy to make sure this process went smoothly, and it did,” said Murray. “That’s a testament to just how experienced and knowledgeable our crews really are.”
Foreman II Electrician Tony Lucero prepares a
transformer for reinstallation of a bushing.
Foreman II Electrician Brian Brameier guides a
500-kilovolt bushing, weighing around 5,000
pounds, into place.
Difficult work such as this requires the
choreography of many craft employees to
complete successfully, safely and without