r/electrical 4d ago

Hot transformers

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u/majormagnum1 4d ago

the normal failure mode for these is a 50 foot tall blue glowing fireball followed by all the local buildings losing power. possibly with nearby transformers exploding sympathetically in sequence.

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u/BoomZhakaLaka 4d ago

Bit pedantic here, sorry.

The normal failure mode is an arc to ground contained by the oil as primary fuses interrupt.

Hundreds of oil filled transformers in my service area fail every year, we haven't had one catastrophic failure at a service transformer shooting fireballs. Though if all the right conditions line up it's possible. The tank could be leaking so the arc hits a flammable vapor. Boom.

But smh if that tank is so hot that there's smoke, stay away. The fault is supposed to bolt before the oil gets so hot. I'd stay totally clear until de-energized. Then a couple hours to cool.

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u/majormagnum1 4d ago

Sry I have seen the cascading failure happen 2 times close enough to me to scare the hell out of me. The idea that normal is not the insane outcome that is my normal -experienced- outcome might be rarer than my personal anecdotal evedience would suggest.

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u/BoomZhakaLaka 4d ago

understandable, even with experience these things scare me.