New Life for PUD Transformer

To the uninitiated, moving 70,000-plus pounds of substation transformer a mere 30 feet might seem a monumental task—and getting it all the way to South Dakota sounds downright crazy. But for the PUD substation crew, it’s just another day at the office.

The eastward journey for the PUD’s 54-year-old Port Ludlow transformer will (hopefully) be a restorative one.

The Port Ludlow transformer faulted in mid-December of 2022, leaving residents largely without power for a full day. Fortunately, a second transformer (purchased in 2020) was on site at the Ludlow substation as part of a planned substation expansion. The PUD substation team, line crews, and contractor crane team from Millican Crane Service in Poulsbo, quickly swapped the damaged transformer.

Loading a 35-ton mass of steel and oil onto a trailer is a game of inches. Too far forward or back on the trailer can make for an unstable load and spell disaster during the 1500-mile trek to its destination in Colman, South Dakota.

T&R Electric, one of the largest transformer rewinding and reconditioning businesses in the U.S., will conduct a thorough inspection of the transformer and suggest a path forward. Inspection involves removal of 3,328 gallons of mineral oil surrounding the essential (and hard to come by) layers of core steel, copper windings, and other internal components. Disassembly and inspection of the transformer is the final determination whether to rebuild or salvage the damaged transformer.

The decision to rebuild the transformer is based upon what T&R Electric finds inside. Rebuild costs can vary (typically between $300,000 – $400,000), and timeline for a rebuild is currently set at 60 weeks. For comparison, a new transformer can take more than 2 years to receive after the order is placed, with a minimum cost of $700,000.

Long-term planning by the PUD aims to upgrade substation equipment throughout the county. The rebuilt transformer will return to the Port Ludlow substation, providing a second bay for greater grid resiliency and expanded service options in the area.