OPD Crews Install Two New Transformers

By VERNON ROBISON

Moapa Valley Progress

It seemed like a complex game of musical chairs for Overton Power District (OPD) crew members one day near the end of last month. But there was much more at stake than people rushing to find a seat as in the familiar party game. Instead, it involved the shuffling of huge pieces of complex electrical equipment from one location to another; each one weighing thousands of pounds.

OPD crews and contractors were busy on Friday, Mar. 31 moving a total of four huge distribution transformers to new homes in three different OPD substations in Mesquite. Two of the transformers were brand new, having only recently been ordered, built and delivered for the district. The other two moves involved equipment that was already in the OPD stock, but which needed to be relocated to keep up with growing power demand.

The project took crews most of the day to complete. In the end, the endeavor was safe and successful and was completed about three hours ahead of schedule, according to OPD Engineering/Operations Manager Jon Jensen.

Jensen said that the end result of all of these efforts would be improved service to OPD customers. “Our main goal is reliability – keeping the lights on for our customers,” he said. “The new equipment will build redundancy in our system and make our service more reliable.”

Distribution transformers, like the units delivered that day, are a major investment for a small utility like the OPD. The units have to be ordered over a year in advance and are built to precise specifications for the needs of the OPD system. The two new units delivered were made by General Electric and each have a 20 megawatt capacity. Their function is to step power down from the high voltage distribution lines to the lines that feed homes and businesses throughout the system.

Jensen explained that the new transformers came equipped with four circuits, instead of the two circuit transformers that are more common in the OPD system. That upgrade brings important benefits to OPD customers, he said.
“It allows us the flexibility to switch power loads across the system,” Jensen said. “If we have a problem somewhere in the system, we can re-route power around that problem and better avoid outages that way.”

The cost of the units were deeply discounted by the manufacturer at $333,000 apiece. Jensen explained that the district had originally put in a request for pricing on just one unit. Though district staff knew that a second transformer would eventually be needed, they were convinced that they would not be able to afford purchasing two at once. But the discounted price on the pair was to good a deal to pass up.
“They offered such good pricing on the two that it just didn’t make sense not to buy the other one,” Jensen said. “Especially since we knew that we would need it eventually.”

Jensen pointed out that the OPD board and senior staff had worked hard in recent years to trim budgets and expenses so that funding was available to make this major infrastructure purchase.
But the money for the two units didn’t all come from the OPD coffers, Jensen said. After all, the need for the new infrastructure had been triggered by continual growth in the area. Construction of new homes and industrial facilities in the northwest portion of Mesquite has brought about the need for additional capacity. So a healthy portion of the infrastructure costs were bourne by developers, Jensen said.
“When the developers propose these projects they agree to pay for the infrastructure they will need to power their homes,” Jensen said. “So a good part of the substation development is paid for by them.”

Still, a part of the cost must be shouldered by the district, Jensen added. That portion is advanced to get the infrastructure in place. But much of the expense is expected to be recovered as future development comes and fills the excess capacity created.
“The benefits of these improvements are more widespread than just supporting the new developments,” Jensen said. “They also help the reliability of the entire system.”

With the two new transformers, the district now has infrastructure that well exceeds the capacity currently needed in that area. When the Dinosaur Substation was built in the northwest end of Mesquite, it was designed to have a 20 megawatt capacity, Jensen said. The transformer on site, however, had only a 10 megawatt capacity. So that unit had to be moved to make way for the new transformers.

OPD crews planned to install the existing unit at the Canyon Substation, also in Mesquite. Because it was full of oil and completely dressed out with all of the necessary eqipment, this unit was actually the heaviest one for the contracted crane operating team to lift. The older unit came in at about 63,000 pounds.

The district also had a need to move another existing transformer, which had been sitting in storage as an emergency backup unit, and move it to the Falcon Substation in western Mesquite where it would be put into service.

All of this moving posed quite a project for both the crane operating team and OPD crews. And it wasn’t going to be cheap. Nevertheless, in carefully planning and scheduling the project, OPD staff had found ways to minimize costs, Jensen said.

Staff was able to schedule the moving of the existing transformers on the same day as the placement of the new units. The transformer manufacturer’s quote just for offloading the new transformers had been $20,000. But staff members decided to pull that piece out of the contract and hire the crane company directly for a full day of work, including the two other moves. This reduced the cost by about half.
As the day dawned on March 31, all the elements were in place. Unfortunately, the day began with a storm blowing through, bringing periods of morning rain. But work continued on the project.
“It was a big project that we had scheduled with the crane operators,” Jensen said. “So the rain wasn’t really going to shut things down. We just had to be mindful of safety with surfaces being wet. Otherwise, the only difference was to wear a raincoat.”

Everything went smoothly and safely throughout the day with all the anticipated work being completed without incident.
“All in all, the day went safely, smoothly and quickly,” Jensen said. “I would like to commend all involved for their dedication and professional approach to making this project a success. A lot was at stake!”