Motor Generator question

[rleonard]

At a local plant, there once was a computer center.  The room was fed with a motor generator to provide clean power to it.  I made an inquirry and the unit might be available. 

It has been years since I saw it, but it was a motor, probably 480 3ph, driving a generator with a large flywheel between them.

Any reason not to pursue it?  Were the old mainframes run off of anything other than 60Hz AC?

I am sure that it was a top quality unit when installed.  I am hoping that it would be a upgrade over the ST15 generator run by my 16-2 Lister CS.  I am working at getting in there to inspect it.

Bob

[Wally]

Were the old mainframes run off of anything other than 60Hz AC?

Street power was converted to 415Hz via a large ups system at the one I was involved with 20 years ago.

The mg set was 600 V  and lots and lots of batteries.

[listerdiesel]

It was possibly a no-break m-g set with batteries, but the set may also have had a conventional UPS, the M-G carrying it over the switch-over time.

Peter

[rleonard]

I finally got in the plant to see the unit.  It is a all GE device.  A 30HP AC motor (240/480 3ph) is in the center.  It drives a flywheel about 3 ft in diameter on one end and a generator on the other.  The Generator is 120/240 1ph 15KW 18 KVA unit.  Meters are on the control box and the device has 39000 hours on it.  It was locked out so I could not start it.  No photos inside the plant allowed.

Even if it needed bearings this probably would be a first class generator.  After all, it drove the computing center.  I am going to attempt to get it for scrap price.  I believe that this would be a big step ahead of an ST generator head in quality and longevity.

It would be interesting to reconfigure this to keep the generator and flywheel intact.  That would certainly smooth out the power from the firing of the engine.  Careful consideration would be needed in the coupling or drive arrangement.

Bob

[rleonard]

Thinking about this some more...

This is probably 60's vintage equipment.  Good stuff.

Now thinking, wouldn't it be cool to remove the center motor and replace with a shaft.  Drive the shaft with the Lister.  Keep the flywheel arrangement!

Hmmmmm


Bob

[rleonard]

First pass at a price was too high for the M-G set.  The millrights are busy with other projects and they may be more negotiable after the first of the year.  I can be patient.  It will be here soon.

Bob

[Jim Mc]

I picked up one of these at a gov't auction.  It turned out to be better than I first thought as the motor in the set was synchronous which, as you might know, is basically the same machine as a alternator.  It was, however a tad  oversize for the typical Listeroid, at 75HP...  Still, it's a nice machine - cast iron housing, 4-pole...

[rleonard]

I just had a conversation with the plant.  They will power the unit up for me so I can hear it run.  We agreed on a price and I should be good to go.

I plan to hook up the Lister 16-2 to it with a step up drive and compliant coulling.

Bob

[mike90045]

You may have to have some sort of clutch for the listeroid drive to the big flywheel. 

 You have a cold diesel, when it fires, has to labor to spin up it's own mass. Add the mass of the new flywheel & generator, and you might break something.  This is wayyyy more load & mass than a ST15. 

[AdeV73]

You may have to have some sort of clutch for the listeroid drive to the big flywheel. 

 You have a cold diesel, when it fires, has to labor to spin up it's own mass. Add the mass of the new flywheel & generator, and you might break something.  This is wayyyy more load & mass than a ST15. 

I've been wondering.... would it be possible to drive a heavy flywheel (e.g. like the arrangement described here) using an automotive torque converter as a "fluid clutch/flywheel" device?

It would allow the engine to be started (at low speed input speed, almost no energy will be transferred through the fluid to the flywheel), and as the RPMs come up, the load will be progressively driven up to speed.

Torque converters are dirt cheep on eBay, or in your local scrappy; the only thing I'm not sure of is, would you need to step up the input speed in order to make the fluid flywheel work properly?

[rleonard]

There has to be a step up device between the 850 RPM engine and the 1800 RPM generator.  I plan to use a flexible shaft connection to absorb the minor speed fluctuation of the Lister.  Just like the Almand drive.  This project is in its infancy.  I have the engine but do not have the M-G set yet.  When I finally get the hardware, I'll sort something out.  I'll post pictures.

Bob

[rleonard]

2 years later and there may be some movement.  A talk with an engineer showed promise.  The millwright that would get it out is on board.  Scheduled to talk tomorrow.

Patience, patience, patience

Bob

[Combustor]

Hello Rleonard,
                    The drive you need for your project is probably a fluid flywheel, and not a torque convertor. The fluid flywheel does much what a centrifugal clutch does, and locks up at a pre-determined speed, usually set by the quantity of fluid filled into the unit. Most torque convertors  only lock when this is included as a feature in the control system of an auto transmission to which they are attached.  Fluid drives are commonly mounted on electric motors to allow them to start equipment with a large inert mass. Used units should be available from suppliers of used industrial gear, in a range of sizes.  Good luck with the project,  Combustor.

[rleonard]

That is a good suggestion Combustor.  I have also had some experience with magnetic particle clutches that could be a consideration.

Bob