Electric System Maintenance Boosts Reliability

PWC’s On-Going Electric System Maintenance Boosts Reliability

By Michael Futch

PWC continues to bolster its electric distribution system, boosting the utility’s reliability to its tens of thousands of coveted customers with the installation of two new transformers over the last month. 

The change to the new transformers, which cost $750,000 apiece, are an integral part of PWC’s reliability enhancement to better serve its approximately 83,000 electric customers.

“We’re the largest municipal utility in the state,” said Jon Rynne, PWC’s Chief Officer for the municipal utility’s electric system, “and the 35th largest in the U.S. and when it comes to reliability, we are in the top 25% for the highest reliability”

PWC substations are some of the most critical points across the grid, and the transformers that operate at the substations (usually two) are extremely important to the overall electric system.

The way the city’s electric system is designed, it starts off at a very high voltage (receiving the electricity at 230,000 volts) before being squeezed down to 67,000 volts, according to Joel Valley, who has worked for PWC for more than seven years. Valley oversees the infrastructure’s 35 substations and other electric support functions.

“We create a network around the city a certain way that electricity travels to each individual substation,” he explained. “When it reaches a substation, it’s reduced down to a street level voltage, like the poles along the road. Then when we get down to a home, it’s stepped down again so that it’s a little less dangerous for the public. So the voltage in our homes are 120 to 240 volts.

By the summer of fiscal 2022, PWC is expected to have replaced 16 major transformers. At least three more are planned in future budget years. While some transformers are replaced, others are actually rebuilt and re-energized.

The transformers’ replacements or rebuilds are an ongoing duty for Valley and his co-workers. To achieve this, PWC looks at the performance of each component. These are manually checked for oil inside the transformers. Valley likened this inspection to the human blood, which is checked regularly by our medical practitioner for general health.

The unit changed out last month by PWC was 48 years old. That particular substation serves the campus of Fayetteville Technical Community College and roughly 3,000 customers in the surrounding neighborhoods. In early June,  PWC also replaced a transformer that serves customers along Cliffdale Road.

“You’re trying to get that 30, 40, maybe even 50 (years of service) out of a transformer’s life. I have some on the system that are 57 years old. You’ve just got to watch them and pamper them a little more, if you will,” Valley said with a laugh.

Why is all this monitoring important for PWC customers to know?

“At any given time if that transformer fails — lights out,” said Valley. “And the timing to move — this thing weighs close to 150,000 pounds — you have to have a big crane. You have to have all these things that you just can’t just snap your finger and everything starts to move.”

It takes a lot of planning, time and effort.

“It is a concerted effort to identify what needs to be done. When it needs to be done. And trying to present the highest value for doing this,” said Rynne, 50, the chief officer for the electric system who has worked for the utility for roughly 4 ½ years. “We don’t want to just replace things if they’re still in good working order just because they’re a certain age. We need to spend our rate payers’ money identifying pieces of the system that need to be addressed so that we can keep them as reliable and safe as possible.”