Novice question for the experts.
Everybody talks about how long and painful it would be to procure new transformers.
How difficult is it to repair/reman the ones shot up?
Depends entirely on the damage. In the attack in question, the cooling systems were damaged.
How difficult is it to repair an engine where the radiator was run dry?
Simple if you shut it down before it overheats, not so simple if the piston rings have welded to the cylinders.
VERY!!!
(BSEE ‘79. In the power bidness)
“How difficult is it to repair/reman the ones shot up?”
Depends. You have a tank that contains oil for heat dissipation; cooling fins, or, external loops containing cooling oil (like a radiator in a car) and a multi-layer (huge) coil of wire inside.
A bullet (or even golf-ball) sized hole through the cooling fins = nothing.
A hole through only the tank with no damage to the internals; not the biggest of big deals in terms of an actual physical repair, no doubt a bigger deal because the tranny has to be inspected (to be sure there is no such internal damage) and the oil inside has to be removed per all manner of HazMat regulations before a patch is welded onto the can. Whether that can be done in the field versus disconnecting and dragging the whole thing back to some shop somewhere, I don’t know.
If the bullet(s) penetrated into the core then the thing is probably shot, no pun intended. The thing is that if a patch job was done, the number of ways it could fail and the idea that the things are supposed to sit there for thirty years basically without maintenance...probably leans towards replacement if there’s any doubt of the integrity.
Point being, for anything other than superficial cooling-fin damage, you better be looking to replace the thing.
Everybody talks about how long and painful it would be to procure new transformers
= = = = = = = = = = = =
Like every so often ‘we’ come up with a brand new idea.
“Lets drill for oil on ________(the North Slope, East Coast, West Coast, Gulf etc etc) fill in the blank”.
“THEY” respond with “No sense in doing that it will be 10 years before we can be using any oil”.
Probably a ‘rational, sane’ response EXCEPT we/they have been ‘playing that game’ for 50 years.......(give or take)
If you put a bullet into the windings, the whole thing will be molten/vaporized copper in a fraction of a second.
You have to unwind and rewind them. Not practical.
They used to be bought in pairs and installed side by side, so that if one blew you could in a couple of hours wire up the spare. Then you can take the bad one out and either fix or order another made.
The problem with transformers are that they are made like suits. They are made according to the part of the grid they have been designed to service.
The only factors that build transformers big enough for our grid are made in Japan and Korea. We only make the smaller ones now.
Transformers do more than step up and step down voltages. They also change the frequency in order to decrease line losses and reduce the heat (another form of loss).
These guys are worried about bullets. You CAN fix windings if you absolutely have to. With EMP, the iron core around which the copper windings are made melt down. Then there is no repair possible.
EMP will also pop holes in the insulators and insulation at various and sundry places in the distribution network, which means you’ve got to deal with the leaks or they will either kill folks and start fires.
You can’t place an emergency order for these like you’d go to Costco to buy a big package of D batteries. That’s why this is a big deal.
How difficult is it to repair/reman the ones shot up?
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Generally, it is faster to repair, all you need to do is rewind the coils, but that is no simple task.
The frame of the transformer is one of the items that take a long time to make, it involves thousands of plates of metal many different sizes and hundreds of them must match exactly.
The big weight of the transformer is copper wire, tons and tons of it, literally. They have to be wound to exact tolerances to be as efficient as possible and to keep them from burning up. They have to be cooled, often with oil tubes running through the plates and coils. Wiring these monstrosities is no simple task and may require over a million bends of wire. This wire is not like you have in the little adapter that powers your computer or laptop but big stuff, much of it too thick to bend by hand.
So, yes repair may be possible and faster than new but that does not make it fast.