How much can you afford to lose? For anyone in charge of production, manufacturing or processing facility, that question must be faced when dealing with a downed power transformer. Transformers are used to increase or decrease the voltages delivered by the electric utility company to meet your specific application. Without one your plant simply can’t function.
While transformers seldom go down, when they do the effects to the bottom line are immediate, devastating, and the loss of operational capability is always crippling. The process gets interrupted, information transfer stops in its tracks and everything comes to a grinding halt.
When disaster strikes, the only thing that counts is getting a replacement transformer as soon as humanly possible. Utilizing a two-pronged approach facility managers can stack the odds in their favor and prevent the loss of hundreds-of-thousands of dollars. First, a quick replacement with an exact match can keep losses to a minimum. In addition, prevention prevails through the proper selection of transformers and quality should also be a top consideration.
No time to lose
According to a story titled The Real Cost of Downtime in Manufacturing by Graham Immerman that appeared in a recent issue of MachineMetrics, the greatest unplanned expense is caused by unexpected downtime. Analyst firm Aberdeen Research found that unplanned downtime can cost a company as much as $260,000 per hour.
Acting as the heartbeat of any manufacturing plant, the failure of a power transformer represents a priority one emergency.
“When the customer called us in a panic to explain that one of his dry-type power transformers burned up and half of his facility was down, we knew we had to act fast,” recalls George Whitcomb, P.E., president of IETC, an industrial commercial electrical contractor based in York, PA.
As a design-build electrical contractor, IETC provides a wide range of services and installations, including replacement of power equipment.
“In general, the biggest issue for us contractors when searching for a rush transformer replacement is reliability, dependability, and promptness,” continues Whitcomb. “The transformer has to arrive ASAP, fit into place with minimal issues, and has to work right the first time.”
In this case, the customer needing a rush transformer was a major manufacturer of threading tools - an electric-intensive industry that draws countless kilowatts-per-hour to run its drills, presses, metal benders, and CNC machines.
“This manufacturer had two, dry-type transformers, each rated at 4160 Volts, stepped down to 480 Volts. One of them failed so half of their facility went down,” recalls Whitcomb. “As a stopgap, they wanted to feed the entire plant from the other unit. Of course, everything went black as they rewired the bussings to transfer the load. But since a single transformer wasn’t sized for full plant demands, they had to dial back their production schedule.”
Any reduction in productivity proves costly, demanding immediate action. As reported in the Thomas Industry Update Newsletter, a survey of 101 manufacturing executives in the automotive industry concluded that the cost of stopped production runs an average $22,000 per minute.
Whitcomb’s company rushed over a tech to see what happened, assess the situation and take measurements. As is often the case, the plant facility manager doesn’t specify the replacement but turns to an electrical contractor for a quick (but lasting) resolution.
“We got the specs and proceeded to see if anyone had one in stock,” says Whitcomb. “I called ELSCO Transformers first because I’d worked with them for years and was lucky to find they had an exact match ready to go. That would greatly reduce the turnaround time, so it came down to availability, reputation, and quality.”
Build quality ensures reliability
Whitcomb understood that transformer construction and materials make a huge difference in terms of reliability. “Whether oil-filled, padmount or dry-type, the design, construction and materials used make a huge difference in terms of transformer reliability,” he says.
For instance, the way the coils are wound around the core of the transformer greatly affects its robustness. Hence, round wound transformers are superior to a rectangular wound because they stay cooler, run quieter, and present less risk of short circuit failure. This enables manufacturers to offer longer warranties - as much as five years as in the case of the new ELSCO dry-type transformer Whitcomb bought here.
Beyond the improved reliability factor, the increased efficiency of the round design consumes less electricity. Some round wound transformers exceed the proposed efficiency standards for Energy Star compliance, drastically lowering utility costs for a manufacturing plant.
What to do when the power goes out
Any plant or facility that’s been in operation for a while is subject to a sudden loss of power since many transformer failures stem from the fact that so many older models are still in place.
“The transformers that failed at our plant were 37 years old—definitely at their end-of-life cycle,” recalls Jonathon Peper, senior engineer at PacifiCorp’s Wyodak Plant in Gillette, WY. PacifiCorp delivers electricity to more than 724,000 homes and businesses in the Northwest through 74 generating plants, 61,500 miles of electric distribution line, and 15,800 miles of transmission line. “Faults, like voltage transients, that they were able to handle when new, are just the final last hurrah. Shorts occur because over the years heat and moisture degrade the insulation, especially paper.”
Peper describes how in July of 2013 they lost a 1.5 MVA transformer that fed a critical piece of equipment. As a result of the fault, the entire plant went down.
“When that happens, we have to purchase electricity from elsewhere at spot market prices,” Peper explains. “That downtime can cost us anywhere from $300,000 to $700,000 per day depending on variations in load peaks, the day of the week, and weather.”
Implementation in record time
To rapidly stem such losses, sourcing a transformer company that specializes in emergency replacement is crucial. For mission-critical applications, transformers can be prepped for shipping within a matter of hours. But to ensure a rapid return to operation, any replacement transformer must duplicate “form, fit and function” as much as possible.
“The big hurdle for us was fitting the new transformer between a 5KV load interrupter switch on one side and the 480 V breakers on the other, so everything was fixed in place on either side,” continues Whitcomb. “We knew every measurement had to be exact in order for the installation to go quickly.”
Still, the arrival of a plant transformer signals the beginning of the real work, where attention to details like the duplication of the high and low voltage busbars can spell the difference between a lengthy and costly replacement process, versus a quick, cost-effective plug-and-play solution.
Whitcomb coordinated with ELSCO to get the dimensions right so they could make the necessary modifications to the transformer before it was shipped out.
“Without that accuracy of tolerances we would have had to modify things in the field and it would have taken a lot longer, but as a result of the effort spent up-front our rigger was able to slide the new transformer right in. It fit like a glove,” added Whitcomb.
“When we explained the quick turnaround to our customer they were ecstatic because they thought they would have to sit and wait 12-16 weeks.”