Power transformers seldom go down, but when they do the effects on campus operations are immediate and devastating. Beyond the lost continuity of classroom instruction, the risk of subsequent fires, fines, security lapses and lawsuits can quadruple the damages.
“Our 4160 volt system was in rough enough shape and fragile enough that it was not uncommon for us to have 3-6 major outages per year,” says Ben Johnson P.E., Assistant Director of Planning, Design, and Construction at Western Kentucky University at the Bowling Green location. “That is obviously not acceptable. Those problems extend your downtime, and when you’re in an academic setting, that’s a killer.”
Figure 1. Replacement transformers must duplicate form, fit and function as much as possible.
At the same time, legacy power transformers represent a huge money drain on an educational institution’s operating budget when they force the campus to pay a steeper price for stepped-down electricity. Spurring the need for replacement is the aging infrastructure at many established teaching institutions. “The units in our substation were 40-60 years old, and were operating at 120-125% of capacity,” continues Johnson. “Since the utility said they would no longer provide 5KV class service we had to change every primary transformer on campus.”
With the current move by utility companies to deliver higher and higher voltages from the grid, many schools, colleges and universities must replace their transformers. “We were looking at a multi-phase process to literally transform our entire campus from a 5KV to 15KV distribution system because our utility company would no longer supply the lower voltage,” said Johnson. “Between that and the occasional failures within our system, not doing anything was no longer an option.”
To rapidly stem such losses, transformer companies exist that specialize in emergency replacement. For mission critical applications, such as on-campus medical clinics, transformers can be prepped for shipping within a matter of hours.
“Attention to details such as duplication of the high and low voltage bus bar spells the difference between a lengthy replacement process versus a quick, cost-effective plug-and-play solution that brings the campus back online in minimal time," says Alan Ober, Vice President of Engineering and Manufacturing for Electric Service Company (ELSCO). Founded in 1912 by former Westinghouse engineers, ELSCO specializes in providing quality new, repaired and rebuilt transformers—under emergency conditions when necessary—from their Cincinnati, Ohio manufacturing plant.
"We were able to design a custom transformer and bus bar solution for WKU that fit into the existing campus switchgear," continues Ober, "carefully duplicating existing form, fit and function as much as possible to help keep power flowing safely and efficiently."
Figure 2. In cases where no exact replacement units are immediately available, similar units are available for rent from companies such as ELSCO until the original plant transformer is remanufactured and back on the pad.
“The main problem I’ve seen with some installations is adapting to existing facilities; it may seem like a small thing but it’s really huge,” cautions Johnson. “Obviously there will be mating and connectivity issues between your substation transformer and the secondary switchgear. I’ve seen cases with mass-produced transformers where at the end of the day you have to kluge it together to make it work. Sometimes it turns into a ‘beat to fit, paint to match’ sort of thing.”
“Our old on-campus equipment dated anywhere from the late 1920s to the 1980s,” continues Johnson. “This is where a custom-designed transformer and bus bar, like we get with the ELSCO transformers, really shines. The known reliability and track record of their transformers played a part in my selection of ELSCO. I’m an EE by trade and have been involved in electrical construction for over 25 years, so I have a respect for hardware.”
As more campuses like WKU—with approximately five million square feet under roof—must switch out dozens of distribution transformers, cables and underground vaults, the process will not take place overnight. Johnson recommends tackling the oldest transformers first.
“Of the 58 buildings we have on campus, I’ve still got about 18 to go so we’re still working it,” adds Johnson. “We replaced our worst equipment first to get them offline before we had more failures. Since we’ve had two-thirds of our system already replaced, obviously our failure rate has gone way down. We’ve never had any issues out of anything we’ve ever put in.”
“For other engineers in the same situation as I’m in here at WKU, I would absolutely recommend replacing your old transformers at your university,” continues Johnson. “Even though we are a public institution and must put everything out to bid, we are permitted to buy from a sole source to alleviate the emergency. Few would argue against a power outage as being an emergency.”