By Philip Reed
On July 30, 2021, a lightning storm caused damage to Gila Substation in Yuma, Arizona, spurring not only immediate collaboration for a solution, but also a lengthy process of replacement and repair that lasted through early this year.
The Gila electrician crew responded quickly after they saw the trouble report, and they immediately saw what had happened.
“There are two transformers in the Gila yard, and one of them was hit by the lightning," said Regional Substation Maintenance Supervisor Miguel Rodriguez. “There's no way to really know if it were a direct hit, unless there were video or a camera, but one of the lightning arrestors did what it was designed to do: It absorbed the lightning and took it to ground."
The lightning arrestor functioned as intended, but then it caused problems of its own.
“It essentially just exploded the lightning arrestor from one of the transformers," Rodriguez explained. “It sent debris all over the place."
Modern lightning arrestors are often made of polymer, but this one was older, made of glass with a porcelain skirt.
“There was broken glass and damage to the bushings," said Rodriguez. “Both sides of the transformer took damage. So then the next step was to assess that damage."
Substation Maintenance Manager Mike Simonton was involved from the start. As soon as the assessment was made, he scheduled meetings with stakeholders and customers to let them know of the situation. He also arranged internal WAPA meetings to keep others abreast of developments and solicit solutions.
A few things were immediately clear from the assessment, such as the fact that the bushings would need to be replaced and the further fact that the age of the equipment would make doing so difficult.
“The transformer was a 1957 vintage, from an Italian manufacturer that has been out of business for quite a while," he continued. “Same scenario for the bushings. They were a little bit newer than the transformer, from 1974, but they were from another Italian brand that's also gone out of business."
Dealing with equipment that old can be difficult. Materials and specifications evolve over time as technology changes and design improves. Finding something from several decades ago from a defunct manufacturer can prove to be a serious roadblock.
Rodriguez reached out to the other regions in the hopes that he would find compatible bushings. He worked with Foreman III Electrician Orry Lesh and Foreman III Electrician Jim Higgins, among others. He reached out to Rocky Mountain, Sierra Nevada and Upper Great Plains, but was unable to find replacements.
“Bushings in particular are kind of tricky, because certain dimensions have to be correct in order to fit into and work with the transformer," said Rodriguez. “Sometimes they're built so tight that you may not have any more room. You may not even have an inch of clearance. These dimensions are critical, and finding bushings that fit became pretty much impossible. We were not finding any."
Delaying repair was not an option.
“The Yuma area is an important part of our system with special priority use power customers, such as the Yuma County Water Users' Association," said Simonton.
“These two transformers are critical to the area," Rodriguez agreed. “They're about seven megavolt amperes each. They're pretty essential to Desert Southwest for all of the loads and the customer needs for the region. This is an irrigation region, meaning that there are a lot of pumps pumping water throughout, and all of this water flow has to stay on schedule."
The system was returned to service by backfeeding it through another line, but that was not a permanent solution and the service it provided would be far less reliable. The clock was ticking.
Solving the problem could not be accomplished in a vacuum and would require significant collaboration. Rodriguez and other staff began reaching out in the hopes that they could find replacement bushings, and quickly.
“At that point in time, we were reaching out to other entities in the area, the customers, everybody that we had contacts for, to try to get replacement bushings," he said. “We reached out to bushing manufacturers. We got responses, but they were saying that they couldn't find them, either."
One of the customers who was contacted suggested reaching out to Transformer Network, based on positive experiences in the past.
“We reached out, and one of the things we heard back was that they had a transformer that was available, sitting at the dock somewhere, and they could easily bring that and rent it to us," said Rodriguez. “Unfortunately, after looking at the specs for that transformer, it was determined that it wouldn't be compatible with our system or our needs."
That may have seemed, at first, like another dead end, but the vendor was actually able to provide some help after all; it just required a little bit of creativity.
“After talking to them and explaining what had happened and what our needs were, they pretty much told us that they were able to basically retrofit the existing transformers," Rodriguez continued. “They took care of our needs by allowing us to use bushings that we could actually find replacements for."
Unfortunately, by the time this potential resolution to the problem was found, it was Aug. 28, with only around one month remaining in the fiscal year.
“It became an urgent need to process a contract for this repair work," said Rodriguez.
Collaboration and coordination between departments was necessary to ensure funding, complete the contract and meet all related administrative responsibilities, not to mention the importance of keeping the permanent repair on track.
So began a long process that had an estimated completion time of 14 weeks.
Transformer Network agreed to repair and refurbish both existing transformers, as well as perform a further inspection on internal components. That required the transportation of both units, which itself was not easy.
“The vendor is based in Florida, but they have shops in South Dakota," said Rodriguez. “So we got the agreement in place and the contract set up, but then we had to set up transport. We arranged for two trucks to come pick these up, then we had to coordinate a crane service so that the transformers could be loaded onto the trailers."
That took care of a few of the outstanding considerations, but it left one question open: How could Gila Substation keep providing reliable service in the meantime?
Rodriguez and others began looking into any available mobile transformers that might suit their immediate needs.
“DSW and Sierra Nevada do not have any mobile transformers," he said. “For WAPA, all the mobile transformers are either at RM or UGP. So then we needed to start looking at what was available and where it was. Did we have a mobile transformer that was the right fit and configuration and voltage to cover both the primary and secondary side?"
It was a lot to consider and a tall order, but he found two of them: One was in Montana and the other was in Nebraska.
“The one in Montana wouldn't work due to its configuration, which left just the one in Gering," explained Rodriguez. “We had to coordinate transport for that, as well. We worked with Orry and the foreman for that area. We had a couple of their electricians and a couple of our electricians hit the road and they met halfway, in Albuquerque, New Mexico, and they swapped drivers and finished the delivery that way."
Upon arrival in Yuma, the mobile transformer was tested, commissioned and installed, keeping service reliable for the customers who depended on it.
“That was a lot to happen in just a little over a month," Rodriguez emphasized. “It really speaks to the great coordination by all of the regions and departments involved. It moved really fast."
“The whole experience highlights excellent customer service, communication and collaboration," Simonton agreed. “It highlights the way DSW was able to coordinate both internally and across regions. It also highlights the amazing crews we have, and how they were able to mobilize and get things done. This cross-germinated with so many groups and organizations, and involved so many different subject matter experts, that it was a great reminder of just how responsive WAPA is and how seriously it takes reliability."
The refurbished transformers were returned, with the second arriving Jan. 21. In the days that followed, it was set on its concrete pad, tested and installed. Both transformers were back in service by Jan. 31.
“I would like to thank our partners in Procurement, Engineering, System Protection, Communications and our transmission-line and substation employees," said Rodriguez. “Our support staff and our customers who provided valuable information were also very helpful in the success of this project."
Note: Reed is a public affairs specialist.
One lightning storm at Gila Substation in Yuma, Arizona, led to a monthslong process of implementing a permanent fx and keeping the power fowing in
The lightning arrestor exploded upon absorbing the strike, and the debris caused
its own damage to the transformer.
A permanent solution to the problem required the temporary use of mobile transformers and the
repair and refurbishment of existing transformers, as well as a good deal of collaboration across