We had a pretty good snow storm here last Thursday and Friday, and as a result we lost power for almost 2 days. The obvious problems were downed trees falling on power lines, as it was a very wet and heavy snow. Being in rural Maine, this is not uncommon. I called the power company, and they did know about it, as I suspected. But that got me wondering: How exactly do they know? Will they know if my area loses power if nobody calls them? Also, do they have any idea of where the problem is, or do they have to actually trace the lines visually?
When I was growing up, we used to lose power regularly, and we always called the utility. Sometimes they knew, but sometimes it was news to them. So I assume that they count on calls from customers to let them know the extent of the outage.
They might use a TDR (time delay reflectometer) on the cables from the plant. A TDR works by sending an electrical pulse down the cable. If there’s a flaw or break in the cable, some of the pulse bounces back. They can then tell not only where the flaw in the cable is, but also the nature of the flaw. Complete breaks, incomplete breaks, grounds, and water in the cable all have their own TDR signature.
Thanks. So the technology exists, but power companies may or may not be using it. One thing I was wondering, was whether or not they know if they’ve fixed the problem. That is, if a repair crew finds a downed line and repairs it, how do they know if there are other breaks in the line. It sounds as if this TDR would let the plant know immediately, and they could keep directing the crews as needed.