There's an intermittent humming from the far side of the street -- sounds like it's in the next neighborhood over, and it sounds like a downed power line.
There's a lot of juice behind the wires; even a drop to a single house from a stepdown transformer is deadly. In our neighborhood, the power company gets "a lot of lights from a single match," and four or five homes might share a transformer. It's protected on the primary side by a big, old-fashioned fuse, often a length of heavy fuse wire clamped inside a ceramic tube. They're set to pop free of the clamps when they go, making a blown fuse easier to find, and they often let go with a bang. But it's a big fuse. It takes a lot of current to blow.
Downstream, your house has breakers or fuses to protect the wiring. Upstream, power companies use "reclosers" on the high-voltage wires: they open up on excessive current, wait a bit and try again. The most common problem on a high-voltage line is a branch or an unfortunate creature, and those problems will usually clear.*
I'm not sure what's going on across the street -- there's no smoke rising and the sound echoes and carries, but I know one thing: stay away! Between that big fuse on the stepdown and the reclosers, a downed power line is often live. It may arc, fall quiet, and then start arcing again, and it may or may not be "live" when it isn't visibly sparking. There's a voltage potential in the ground under your feet, highest where the current goes to ground and diminishing over distance. Get too close, take a long step and you're in danger before anything is obvious.
The sound gnaws at me. I have been too close to power problems a few times over the course of my work and the more you see what happens when it goes wrong, the less safe you feel.
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* There is a tradeoff between excessive "nuisance trips" and protecting the system. Reclosers are one of the compromises, and one that works well more often than not. But they're also why you can never assume that a downed power line is safe.
I lived in Florida for several years and when it was really humid the power lines would emit a crackling hum that disconcerting and down right weird. And I've seen bad things that electricity has caused. I with you in that respect.
ReplyDeleteOne of my favorite videos shot by our current chief photojournalist is from an ice storm when a limb crossed two phases of a 13KV power line and created a really big horizontal version of a Jacob's ladder until it ended at the next crossarm. Zzzzzzzzt-BOOM!
ReplyDeleteI had a brief stint doing high power electromagnetics for the Navy, and your closing thought sent real chills.
ReplyDeleteLast spring on a wet day the nearest power-pole to us has a pole-top fire; Dirt and dust that have collected on the insulators, when combined with moisture from rain, can create 'tracking' of the current between phases that will heat to above the ignition point of the wood pole. Reportedly a very common thing, but not something I had seen before.
ReplyDeleteIt looked just like some boy-scout had decided to make a small cooking fire on the top of the pole. Until the power company came to do a proper shut off, the local fire people just chased embers that reached ground to make sure they did not cause any fire spread.
One of my old Florida neighborhoods had a pretty regular occurrence of squirrels getting too close to the transformer terminals on the pole, and turning into flashbulbs. It's amazing how much light one can put out in such a situation.
ReplyDeleteI thought the asterisk was going to lead to something about fried squirrel! :)
ReplyDeleteSome years back, I heard a bang and crackling up the street after dark during heavy weather. I looked out the front door and, while I couldn't see where the 'fun' happening, thereafter there was an even louder band and the purest bright emerald green flash out from behind the foliage. Hmmmm, must have been some copper....
ReplyDelete3AM binge-watching the The Outer Limits: just as the invading UFOs are about to start vaporizing everybody, the sky outside my window lights up actinic green and there's a LOUD 60Hz buzz. OMG, my sleep-deprived brain went into hyperdrive. An errant automobile took out the local substation. Jeebus!
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