40KW 3PH generator head

Hello!

I bought a couple of compressors previously used on an old fire truck and they came with a big 3PH generator head that had been driven off a PTO to power them.

I don't really need this thing but I figure maybe someone out there might want to couple it to an engine and turn it into a standby power source for his shop. Or whatever. Anyway, this seems like the kinda audience that might have a use for something like this :-)

It's a big sucker. Probably about 600#. I've got it in the SF Bay Area in California but happy to bolt it to a pallet if you want it delivered.

I don't have any way to confirm that it works, but I'd be VERY surprised if there are issues. The shaft spins smoothly and there's not that much likely to go wrong with the rest of it. Regardless, in the unlikely event there are issues the copper inside it is going to be worth more than the shipping so you'd come out ahead anyway.

Photo of info plate below. Modern versions of these things appear to run around $4500-5000. I'm asking $1750.


Thanks!

-Ben

If I figured halfway correct, it would take at least 100 H.P. gas engine to run it. I have no need with it, just curious. Good luck.

JH

James H Clark said:

If I figured halfway correct, it would take at least 100 H.P. gas engine to run it. I have no need with it, just curious. Good luck.

JH

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Yep. That's about what I figured. At least to run it at full load. The PTO was off a GM 350 which certainly has the power. I figure if someone has an old Detroit 3-71 or something similar lying around it'd be pretty easy to hook the two up and have an inexpensive power source.

We'll see!

-Ben

benha said:

Yep. That's about what I figured. At least to run it at full load. The PTO was off a GM 350 which certainly has the power. I figure if someone has an old Detroit 3-71 or something similar lying around it'd be pretty easy to hook the two up and have an inexpensive power source.

We'll see!

-Ben

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Not really the hard part is governing the engine to hold proper rpm under any load, not easy at all.

Ah. Good point. I actually have the control panel (two, actually) that was used to manage the generator which presumably has at least the logic section of that piece. I'll post photos of that this weekend.

benha said:

Ah. Good point. I actually have the control panel (two, actually) that was used to manage the generator which presumably has at least the logic section of that piece. I'll post photos of that this weekend.

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You need to do your homework if you want to sell this. You should also use the correct terminology and you have not. I don't know what a generator head is. I do know what an alternator is. In which case and if I was in the market for one, I would want to know the number of poles, so I could determine the speed to spin it. I would also like to know the output shaft diameter and the number of main bearings in the housing and if only one bearing, the SAE drive housing required #2, #3, #4 etc. whatever. If however, you only want to sell it for copper scrap, your description is perfect as is.

Hi, Steve.

Thanks for the input. This isn't an area of expertise for me so forgive the poor description. I appreciate the refined terminology.

Anyway my hope was that people could get what they needed from the data plate, but it looks like the posting system seems to have shrunk the info plate to a size that makes it unreadable, so let me provide that info here:

MAC Self Regulated Dripproof Synchronous Alternator
S/N: AD 165 99 CRJ
PN: 3165A-0085A
Frame: 360
Lead: 12
Ambient: 40
RPM: 1800
Phase: 3
HZ: 60

Continuous Duty Rating Class F Insulation
KW: 40
KVA: 50
C Rise: 80
PF: .8

Low Conn Wye: 120/20A Volt 139 AMPS

Made by Lima Electric Co., Inc.



That's all I know from here. I'll measure the output shaft this weekend. It was belt drive so it clearly has at least two main bearings since the output end was self supporting. I have no idea how to figure out if there are more than that.

If anyone has thoughts on the kind of place people would be looking for one of these I'm all ears. I thought of PM because it's an audience of mechanically savvy people that use a lot of 3PH equipment. But for all I know there's a far more applicable forum out there somewhere.

Thanks again,
-Ben

That’s why he said Detroit. If you get one with a hydraulic governor it will work great for a genset application. I have had less issues with a hydraulic governor than with the newer computer controlled engines. I have a few 371, 471, 671t that all work great as a generators as long as you can stand the noise.

Heh, well, I was just thinking it'd be likely to be cheap and lying around more than that it had a hydraulic governor, but I'll pretend I knew what I was talking about ;-)

moonlight machine said:

Not really the hard part is governing the engine to hold proper rpm under any load, not easy at all.

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25 years ago I had a customer that was involved in state energy research. They built several 30 and 40 KW gen sets all powered with Chevy 350 engines running on Nat Gas. Engine rpm was 2500, compression ratio was 16:1. The units were run round the clock for weeks at a time at various loads for life cycle testing. Each rig was equipped with an electronic governor. Many times I was involved in discussion about the various equipment, and I remember a demonstration once where they were switching a 20kw load off and on, and looking at the various gauges, etc, the sound would vary, but the rpm change was not noticeable on the tachometer or the frequency meter. Pretty impressive seeing the throttle shaft snap open or closed instantly. I'm sure the equipment was costly but it got the job done very well.

steve-l said:

You need to do your homework if you want to sell this. You should also use the correct terminology and you have not. I don't know what a generator head is.

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Anybody that knows anything about Generators, knows what a Generator Head is.
And common sense pretty much clue's the rest of the folks in as well.
So yes, he has used perfectly acceptable terminology to describe what he's selling.
You, on the other hand, need to brush up on the terminology associated with Generators and related equipment. Just because you don't know what he's talking about does not make his ad wrong.

Though I'm not sure this is turning out to be the right place to sell this thing, if you're interested I've got more photos and such now, and it's up on eBay:

4KW 3-Phase Generator Head (Alternator) and Controls | eBay

If you would take it to a motor shop and pay to have it tested for continuity
and hi-pot, would go a long way for buyer confidence.

Fair point. My preference would be to find someone that's interested in this thing and if that's a condition of purchase I can get it inspected. It's a royal pain to move this thing around. But definitely worth it if/when I can find the person that wants this thing.