Work crews took advantage of a back-up transformer Saturday afternoon to repair a massive power outage that knocked out electricity for much of Cullman County and the City of Cullman.

A large swath of Cullman County went dark for approximately five hours when one of the main transformers inside the north Cullman substation, located at the intersection of Alabama Hwy. 157 and U.S. Hwy. 31, failed on Saturday afternoon.

Repair crews from the Cullman Electric Cooperative and Cullman Power Board worked for the next several hours to transition the power load onto a back-up transformer housed at the substation, which was ultimately used to restore service across the area.

“As far as making those repairs, when an outage like that occurs it’s not extremely complicated, but it’s just a matter of getting all the connections hooked up to the back-up transformer there,” Co-op spokesperson Brian Lacy explained. “That is a fairly time-consuming process. Once everything is connected, and you turn it on, it takes some time for that transformer to warm up. You can’t just flip the switch all at once, or that could cause the entire substation to go out again. You have to bring it on a little at a time.”

Lacy said the failure could have been exacerbated by a variety of factors, including the recent cold temperatures and increased power consumption, though he noted it was likely the result of “aging equipment.”

“About two years ago we had a similar power outage, under very similar circumstances, and we used the back-up transformer and had to switch everything over,” he said. “Even at that point, we started working on long-term plans to make the upgrades and get newer equipment in there. Some of the oldest equipment at that station actually dates back to the 1960s.”

Had a back-up transformer not been installed and maintained at the site, Lacy noted the outage could have potentially lasted for several days as opposed to just a few hours.

“Those types of transformers are literally the size of a house, they’re absolutely massive,” he said. “You saw 15,000 people go out from that because it is one of TVA’s main transmission lines that feed in there, then it goes out to smaller substations across the county. From Holly Pond, to Berlin and Jones Chapel. That’s why you saw outages all over.”

Lacy noted the co-op, power board and Tennessee Valley Authority have been actively working to make upgrades at the station in an effort to avoid outages just like the one that hit the area this weekend. Those upgrades should be complete within six months.

* Trent Moore can be reached by e-mail at trentm@cullmantimes.com, or by telephone at 734-2131, ext. 134.