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Comment by butler14 | Hacker News Reader

I have a substation in my back yard, approximately 15ft from my house.

Anyone have a sense of what "damage to transformers" means? Like, it frazzles out in its own housing, or takes half my street out?

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In practice all large enough transformers will have protective equipment to disconnect them from the grid in conditions of overcurrent, such as might be caused by exceptionally severe solar storms or nuclear EMPs. This has its own downsides (turning on the grid from scratch is an extremely complex operation as power plants themselves need electricity to operate) but the risk of a substation transformer exploding as a result from incorrect line voltage is minuscule IMO.

It is possible that smaller control equipment might fail as those are usually more fragile electromagnetically speaking, but once again that would be a problem for getting power back online, not in the "transformer explodes" kind of way.

If they're oil cooled transformers then they do have a tendency of catching on fire. It won't take half your street out but I wouldn't want to be 15 feet from one that's on fire.

Oh stop fearmongering. "A tendency of catching on fire" makes it sound like that happens every week. Fires in substation transformers are extremely rare and any given transformer is unlikely to see any significant incident in its rated life.

Of course if one gets hits by a meteorite and catches fire then keep a safe distance. Definitely more than 15 feet. In normal operation they are extremely safe though.

Thanks!

Having been a first responder to a fire in a shopping centre sub station/transformer where a technician lost their life in the incident, I do have a limited amount of experience around transformer fires, and I don't necessarily see my comment as 'fear mongering'. Particularly when the context is the question the person above me asked (failure modes of large substations). Under normal operation they are safe, and in abnormal circumstances they can catch on fire.

When I was a child, a pole-mounted transformer on my street exploded, making a huge, earth-shaking boom and taking the top of the pole it was mounted on with it. It scattered debris widely.

A hazmat crew in full bunny suits showed up to clean up the mess. The story I remember (this was a long time ago) is that PCBs were present -- I think they stopped using PCBs in these things since then -- and that was why the hazmat team was needed.

It was quite exciting, though, and remains a vivid memory.

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