The electricity in our neighborhood went out about 2:30 yesterday afternoon. Power was not restored until 3:40 this morning. ( I had been asleep intermittently during the evening and early morning.)
A neighbor said he saw puffs of smoke issuing from adjacent utility poles along our street, just as the power went out. All I ever thought is that there are “transformers” on those poles.
Between the power plant and the habitations supplied with electricity, what all is there along the lines that can go wrong besides the lines themselves?
Breakers and their actuators can go bad. High voltage lines are also fitted with expulsion fuses that are single-use things. The fuse element is surrounded by a chemical that explodes rather violently when heated; when the fuse element cooks off because of overcurrent, this chemical explodes and violently blasts the molten fuse element out of one end of the container, assuring that the current is reliably interrupted instead of forming an enduring arc through the molten/vaporized fuse material. Replacement of an expulsion fuse shouldn’t take 13 hours, though. a transformer that has malfunctioned badly enough to need replacement might take a good bit of time, though - and if its failure somehow caused damage elsewhere in the circuit, then the line crew may have more than one thing to take care of before they can restore power.
Well, I went to the utility company’s website several times; they have a map showing locations of local outages. The data on our outage first said (around 4 p.m.) that it would be corrected about 5:30 p.m., then 3:00 a.m., then 6:00 a.m. ( I saw this last estimate when I checked it just after 3 a.m.). It didn’t help that fog rolled in last night.
Something making smoke could be the result of the problem and not the actual problem itself. For example, if a pole gets hit by a car and it drops higher voltage lines down onto lower voltage lines, a lot of stuff on the lower voltage circuit can get fried.
Transformers can make smoke when they go, too.
Anyway, as for what else is up there, you might see fuses as Machine Elf said, or reclosers, which are kinda like automatic circuit breakers. If a circuit breaker pops in your house, you just go down to where the breaker box is and you flip it back on. That’s a bit more difficult for the power company when the “breaker” is miles away from any person. So a recloser waits to see if the fault clears on its own, then automatically switches the power back on. Reclosers are programmable, but the way they are usually programmed is they try a few times fairly quickly (maybe at 1 and 2 seconds after the fault), then wait a bit, and then try one last time after maybe a couple of minutes. If that doesn’t get the power back on, then they quit and a lineman has to go out and see what the problem is. Since most faults are fairly transitory (like a tree branch blowing into power lines in the wind, or high winds blowing two lines together), reclosers are great for preventing the power from going off for more than a short time.
You might also see capacitors on the line. These are used to correct the power factor of the line to make things more efficient. There are capacitors at the substation which are switched on and off of the line as needed, and you may also see some that are mounted on utility poles, especially on longer rural runs.
Most of the capacitors that I have seen have been in square cases, where transformer cases are usually round.
The puffs of smoke could also be from an unfortunate squirrel or bird.
Here’s a great video of numerous things going wrong at once.
The video owner’s notes provide a great explanation of what’s happening in the video.
Well what does blow up are the transformers… they are cutting it fine on the insulation. only just sufficient … for maximum efficiency…
A weakness in the insulation and its shorting out and burning up.