PUD Upgrades Transformer at Scappoose Substation

Riggers from Wilhelm Trucking
Riggers from Wilhelm Trucking & Rigging watch closely as the new transformer begins moving off the truck and down the rails to the concrete pad.

January 9, 2012 – Columbia River PUD energized a new substation transformer on Thursday that will improve reliability, replace aged equipment and accommodate future growth in the Scappoose area.

A substation transformer plays a vital role in the electrical grid. It converts the transmission voltage of 115,000 volts to 12,500 volts for delivery throughout the PUD’s service area. A single substation transformer will serve several thousand homes and businesses.

The PUD’s new transformer has a maximum load capacity of 28 megavolt-amperes (MVA). It is more energy efficient and has more capacity than the 8 MVA, 50-year old transformer it replaces. The new transformer is large enough to accommodate new development in the Scappoose area and to provide a backup power source to customers in the Warren and Dutch Canyon areas.

“This new transformer will provide reliable electric service to Scappoose for the next 50 years,” said PUD Engineering & Operations Manager Steve Hursh.

In November, Olinger Transport hauled the transformer from its manufacturing site at CG Power Systems in St. Louis Missouri to Scappoose. While the cross-country journey was uneventful, moving the 50-ton, $520,000 transformer off the truck and onto the reinforced concrete pad inside the substation took a bit of ingenuity. A crew of riggers from Wilhelm Trucking & Rigging in Portland, Oregon used an old-fashioned “jack & roll” technique to slowly and safely move the transformer past existing substation equipment and into place.

Once the transformer was in place, PUD line crews installed high-voltage bushings, cooling radiators and surge arrestors to protect the transformer from damage. After thorough testing to ensure everything would function properly, the transformer was energized and connected to the PUD’s power grid.

This transformer is the first substation transformer that the PUD has purchased since 2000, when Don Nys Substation in Rainier was constructed. It is one of two new substation transformers the PUD purchased in 2011. The second transformer is the same model and will be used in a new substation planned for 2013 near the Fairgrounds in St. Helens.

“These transformers have been part of our long-term capital plan to improve reliability and add capacity to the service territory. We were very fortunate to be able to take advantage of low market prices and to receive a competitive bid from a U.S. manufacturer,” said PUD Engineering & Operations Manager Steve Hursh. “We saved quite a bit of money by placing our orders while metal prices were down.”

The PUD’s long-range capital improvement plan includes construction of the Fairgrounds Substation in 2013, replacement of the transformer at Rosehill Substation in St. Helens in 2015, and replacement of the transformer at St. Helens #3 Substation in 2017. The PUD utilizes cash from reserves for its substation transformer purchases and other system improvements, to eliminate the need for long-term borrowing.