Always interesting to see the innards of machinery- especially the "ohhhh, that's how that works!" moments. But not so much the "there's more going on in here than I though... how do you fix it?"

Well, 210 RPM, and 60Hz operation, so the maths is simple, 210 poles in the generator, so each of the thick rotor busbars that go down the length of the rotor occupies 1.7 degrees of rotation, and the same for the stator. Looks like the rotor is just a single wire down, so those copper bars, brazed to the thick copper top bus bar shown, has to carry a pretty high current, thus the cables from the exciter brush set being made with plenty of copper in them. Still, those cables probably account for more than half the power dissipation in the rotor excitation, the rest being in the brush assemblies, and in the circulating AC current that flows in the rotor itself. That set of losses is likely why the other alternator sets got converted to have a bridge rectifier in the top section, to remove the 2 sets of high current brushes, but leave the magnetic coupling to allow control of the excitation current. Just means you need a rotary transformer to get the AC current flow in the winding before the rectifier, so as to read your excitation current, and check that your exciter is still functioning properly. But a bonus is that cooling the rectifier is easy, you already have a massive air flow to cool the stator anyway, so the original selenium or copper oxide rectifiers they put in would have run cool, just would have had massive parallel plate sets for the current. Modern silicon is smaller, but still has the same cooling need, though there you can get a big efficiency jump using modern active rectifiers, which probably could do the 200A current, with losses under 100W.

This is a shutdown I’d love to be a part of!! Thanks Chris

I can't thank you enough for making this knowledge fun as hell.

Very cool stuff indeed! Look forward to the other videos. Merry Christmas!

Former meter technician 2. Have been inside a few hydro stations in my past life and this is super interesting stuff! I wish the folks i worked with had your enthusiasm, if so I might still be a meter tech. Instead I hit things with a hammer! 😊

Not often you get to see the inside of these. I recall touring a dam here in lower Michigan. You could look at this stuff but no photography due to national security. I recall one of the employees sayings they wanted to get photos of the inner workings of the turbine for demonstration purposes , but were not allowed to do so. A little extreme if you ask me, as the dam wasn't anything new nor were they showcasing anything you couldnt find on the web regarding how it was constructed or how it worked.

that rotor is flithy.

EM=Electric Machine Company. In Nebraska several small hydroelectric plants were equipped with this brand of generator.

Some dish soap and a compressor blow air after soaking the wires in dish soap 😊

It’s a topless generator. Talk about E/E porn! Cool vid. Thanks for sharing.

Love your videos.

Love your videos, they are fantastic. Also, you're throwing off some serious AvE vibes, I approve.

what is the stator voltage? is it generating at 2,5kV or less?

Are they really thick windings or are there thinner wires inside

Correction: Electric Machinery Company, and it still exists in Minneapolis, Minnesota.

2 sets of 12 poles?

How old is this generator ?

lewd!

34 poles

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