Squirreled away: Utility blips a force of nature
Published 12:43 pm Saturday, August 10, 2013
![VAIL STEWART RUMLEY | DAILY NEWS ON THE GRID: Washington Utilities’ SCADA (Supervisory Control and Data Acquisition) system shows what’s going electrically throughout the city. Employees monitor the entire system from the agency’s central office.](https://www.thewashingtondailynews.com/wp-content/uploads/sites/12/2013/08/NEWS_SQUIRELLED-AWAY_130811_WEB.jpg)
VAIL STEWART RUMLEY | DAILY NEWS
ON THE GRID: Washington Utilities’ SCADA (Supervisory Control and Data Acquisition) system shows what’s going electrically throughout the city. Employees monitor the entire system from the agency’s central office.
The power doesn’t really go out — it just blinks. It’s a momentary lapse of electricity, just enough to make the lights flicker overhead and reset every digital clock in a home or business. The occurrence isn’t an indication something is wrong with the system. Instead, it’s a sign the system, a fuse, is healing itself of a fault in the circuit. And at this time of year, that fault can be safely attributed to one of our furry friends: the gray squirrel.
“Right now the squirrels are mating — this is their time of year,” said Washington Utilities Director Keith Hardt. “I hate to tell people that it’s squirrels, but it really is … Most cities with restrictions on cutting trees have this problem.”
Hardt said the problem is unique to downtown Washington customers who are hooked into the Second Street feeder line. It covers the majority of downtown, from the wastewater treatment facility on West Third and Plymouth streets to the end of East Main Street, near the Havens Gardens boat ramps. He attributes the number of “blinks” in the circuit to the close proximity of large, old trees favored by squirrels and overhead power lines, not to mention this summer’s cooler temperatures that have made an already healthy squirrel population even more active.
“Between squirrels and geese, we have a lot of wildlife in downtown Washington,” he said.
Hardt explained that a “blink” occurs when the system recognizes a fault; a circuit is allowed three “blinks” before it shuts down. When a squirrel vaults from a tree to the cross arm of a utility pole, it may get a little too close to the action and become an inadvertent ground for either 12,500 or 34,500 volts, depending on which line it hits. Feeder lines carry the higher voltage.
“They (squirrels) like to sit on the transformers — and it could be (contact with) an insulator on the pole, or any other hardware up there,” Hardt said. “But if it gets within two or three inches, it will create a path to ground.”
In layman’s terms, that means a squirrel gets zapped with a whole lot of electricity.
Washington Utilities’ SCADA (Supervisory Control and Data Acquisition) system logs all the “blinks” on the circuit: two occurred in the past week; one prior to those happened three weeks ago. With the program, a log is created and Washington Utilities employees can narrow down the area of the fault. When it happens several times, they know there’s a larger issue.
“Very rarely do we have an equipment failure,” Hardt said. “Usually, it’s outside forces that we can’t control.”
As to those outside forces, not all the blame can be placed on squirrels. Statistically, eastern North Carolina has one of the highest rates of lightning strikes in the country, a phenomena geologists chalk up to the region’s salty soil and its conductivity. Measures have been taken to protect against that type of outage, as Washington Utilities’ transformers are equipped with grounds that disperse energy from a lightning strike. But trees and their limbs have been an ongoing problem, as well — especially in Washington’s historic district, Hardt explained.
“We’re always on the lookout for tree interference. But we have a hard time getting people to let us trim on their property in town,” he said.
Hardt encourages those who have experienced more “blinks” than the three logged in the past three weeks to keep their own log and share it: Washington Utilities employees regularly work with customers one on one to determine if a problem is within a home or business.
But until temperatures cool down in the fall, Hardt said squirrels will continue to be a nuisance to Washington Utilities and its downtown customers.