Comment by tharkun__
12 hours ago
This. Same timeframe and I've lived through both lots of lightning storms and in areas with lots of power failures. Some of them intermittent and essentially caused by transformers blowing up. Like earlier this winter, we had multiple storms where you'd hear a transformer blow up, in many cases even seeing the sky light up as well from it, power going out, couple seconds, power coming back, next transformer blowing out, rinse, repeat.
On the other hand I've read about plenty of stories of the "cheap" UPSs you'd usually buy as a consumer (not to name any brands coz I've never had any) actually causing such issues in the first place. Without any actual surges from the grid.
That said, being totally not superstitious (for real, but someone's gonna "kill me" if they find out I wrote this and something dies from a surge...), now I guess I need to knock on wood like seventeen times ...
I do use surge protectors when we're on generator power temporarily.
The things people often call "transformers blowing up" are usually not transformers blowing up.
Instead, it's usually just overhead wires that are too close or literally touching, often from influences like wind and ice. The electricity arcs between the wires, creating bright blue-white flashes that can be seen from far away, sometimes with instantaneous heat that makes hunks of metal wire evaporate explosively. It can be violent and loud, and repetitious as different parts of even a single run fail.
Transformers can certainly blow up, but that's less common. They're (generally) filled with oil for cooling purposes, and they're massive things that tend to take time to get hot. A failed transformer can produce arcing and blue-white light, but if things are that hot then the oil is also ready to burn.
And when the oil burns it isn't blue-white -- it burns with about the same yellow-orange color we saw the last time we accidentally flambéed dinner on the kitchen stove, or a Hollywood fireball.
A bright flash without a fire is probably not a transformer.
Here's a video of a transformer actually-exploding (note the prominent fireball): https://www.youtube.com/watch?v=oFkfd31Wpng
And here's a video of what someone describes as a transformer exploding, even though there are no transformers in the video: https://www.youtube.com/watch?v=rHVh0KwG_0k
Haha, I hear you. But yes, it really is transformers blowing up sometimes. Sometimes it really is just branches blowing up the line, sure.
A branch hitting a wire, happenes all the time here too. Lots of trees in this community. The video of a transformer you shared: that's not the transformer I'm talking about. That's at a transformer station.
I'm talking transformer on a street pole. The kind that hangs right across the street from me. This kind: https://www.youtube.com/shorts/y3E7avUvj6I
See it's the kind in your second video. It's a transformer. You just chose a narrower definition I suppose. It's a https://en.wikipedia.org/wiki/Distribution_transformer ;)
And yes, I know it's transformers and not just wires (but also wires do happen definitely) coz I do walk the neighborhood regularly and I can tell when a transformer is new vs. old up there. Ours is old. The ones a few streets over sometimes are very new and I see the Hydro trucks go by the next day(s) to make them new ;)
Again, like seventeen times knock on wood but the ones next to us have not actually blown up. But three streets over, seen the new ones. Literally last weekend, we had an ice storm come through and while no blowouts we could see or hear, the outage map showed plenty of failure.
Definitely use quality surge protectors on expensive equipment connected to generators.
PSA: UPSes and GFCI/GFI extension cords won't work properly when connected to a stand-alone generator with a bonded neutral. I've tried using enterprise UPSes on such generators, but they absolutely won't work. In such scenarios, debond the generator's ground from neutral, apply a very large warning label to it being debonded, and drive a massive ground rod electrode into the ground as close to the generator as possible and ground the neutral there. This does work and is much safer because there's a stable voltage reference source. It's more of a hassle but can be necessary for some off grid and temporary scenarios.
It's not just cheap UPSes, it's cheap surge protectors as well. They exist because the vendor can throw in a MOV costing a few cents and increase the price of the power strip by 50%, not because they're any good. MOVs are sacrificial components which have either degraded to uselessness by the time they're actually needed or, if they're still working, can explode or catch fire from the energy dissipated. Even if they don't, all they're doing is converting an x-kV spike on active into an around-x-kV spike on neutral or ground. If you want to do it properly, use a series tracking filter, not a "surge protector".
No offense, but can you tell me how my 4.5 kW generator is gonna generate that kind of power surge?
One scenario: there's a short circuit somewhere, say rats chewing through insulation. This can cause a very high current through the short. A non-inverter 4500 watt 120 volt generator might have 0.2 ohms coil resistance, so the short circuit current can hit 170 volts / 0.2 ohm = 850 amps. When the shorted branch's circuit breaker trips, the inductance in the generating windings wants to keep that 850 amps flowing for at least a few microseconds, and it gets distributed across everything else that's still connected. Depending on what else is connected (hopefully including some surge protectors) the peak voltage can get into many kilovolts.
The circuit is something like this: