Motor - Generator question

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 inquiry 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

Reply to
bob_1fs
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Reply to
RoyJ

That was the original design for a UPS (uninteruptable power supply ). The big flywheel kept the generator going until an emergency generator could come on line or the computer could shut down in an orderly fashion.

Reply to
john

They were a good low-tech idea in their day, even if they weren't very efficient considering all that mass you had to keep spinning.

The ones that were motor=clutch=generator=clutch=engine would provide output with only a momentary frequency and voltage sag as they switched over - as long as the engine was kept hot and ready, and it started normally when they dropped the clutch...

But make DAMNED sure you rebuild the bearings before you put it back in service, and have thermostat sensors and alarms on all the shaft bearings. Top and bottom halves of the shells.

With that much energy stored in a huge rotating mass, if one bearing gets hot to the point of seizing up I can guarantee that all nine circles of hell is going to break loose very quickly....

It has happened in the past, and it will totally trash the power room and anything else that gets in the way like a bull in a china shop - including people running to find out what all the commotion is. People are soft and squish quite easily in those situations.

-->--

Reply to
Bruce L. Bergman

Not an ansewr just a story...

35 years ago I had a friend who was going graduate work in high energy physics at Berkley. Those were they days when they started the "beam" in the HV room feed it to the linear accelerator and then fed it's output into the Bevetron (Bevetron stands for Billion Electron Volts, at the time the biggest cylotron in existance, and looks like a joke now compared to CERN but I digress) That HV room was quite a sight, looked like something out Buck Rodgers... but MOST impressive was the two M-G's they had. The Bevetron took soo much energy that they couldn't power it directly off the utility grid, had to spin up these HUMONGOUS flywheels with the M-G's.. further more since the Bevetron like all cylotrons used pulses of power they need something to be the bigassed "capacitors" and that was the flywheels on the M-G's... Those flywheels were solid cast iron, three feet wide and 12 feet tall and were arranged so when they spun the turned going UP the hilll... they containd so much kenitic energy that if they ever broke loose and went DOWN hill they would have plowed all the way through downtown Berkley and wound up in the bay... As it was one old timer figured if they broke loose going UP hill they have wound up in Orinda.

Ahh BIG Science :-)

--.- Dave

Reply to
Dave August

Yes, many mid-sized IBM 370 mainframes even had integral 415 Hz motor-alternator sets built into the cabinets. The larger systems had separate M-G sets or battery backup systems with inverters in them.

The IBM 370-135 had a 17 KVA motor-alternator set that produced

415 Hz, 3-phase power at 120 V L-L, I think. (I could be wrong on the L-L voltage, it has been a LONG time since I worked with that stuff.)

Why, on earth, do you WANT such an antique? Even if it is for a more conventional voltage and frequency, it is most likely HUGE, as they used one flywheel system for the entire data center.

Jon

Reply to
Jon Elson

Why would someone want an old steam engine with a flywheel that size? :)

Reply to
Michael A. Terrell

Well, it certainly wouldn't mind when you started up that big 3-phase lathe...

Reply to
Tim Wescott

Some folk collect antiques. Have pleasure from them. Some use them for all sorts of reasons. Take your Model "T" Ford for example. Some what impractical for todays's commuting but lots of folk have them cos they just want to. theres no harm in that.

Im a metal worker, and collect old metal working tools. I have lots of smith's tools from 1800. Some from before that.about 1500 AD. I use lots of them, for all sorts of reasons. Currently im at 2200 off a 2500 contract for hot forged commemorative plaques for the 40th year of the Great Dorset Steam fair. There minted on an 1880 Hazelwood and Dent, Birmingham UK. drop hammer, Hammer weight 300lbs. Gives about 100 tons dynamic energy. Lovely machine. As good as new. Yes, the brass plaques could be made on an automatic,strip fed power press , but the results just arnt the same. So, If you want a vintage motor generator, you have one. And dont listen to all those folk that ask what do you want that for?

Ive a diesel generator circa 1942. 20kva. Still starts, runs and generates fine. Weighs 2 tons. Use it to power a very large stick welder. no electronics, all electromechanical controls, repairable and simple.

.
Reply to
Ted Frater

Hmm ... unlikely to be used just to clean the power. I'll bet that it produced 400 Hz as well.

Yes -- some at least ran from 400 Hz to allow smaller lighter power supplies scattered closer to the points where they were used. 400 Hz in place of 60 Hz results in a major decrease in the iron needed in transformers. And the components were easier to get at that frequency than at higher ones, because 400 Hz power was common in aircraft.

What were you planning to power with it? And do you have enough power to spin it up? If so you probably have a serious shop, not a hobby one.

Enjoy, DoN.

Reply to
DoN. Nichols

[ ... ]

Well ... They could still save money, by improving the power factor seen by the service meter.

Hmm ... the one where I used to work -- used to keep the chem lab exhaust blowers working during a power outage -- was a little different:

motor/generator=flywheel=flex-coupling=clutch=diesel-engine

and when the power failed, and the flywheel cranked the diesel to an instant start, the three-phase motor became the generator.

This is not enough, as proven by what happened to ours. There were big self-aligning roller bearing assemblies in pillow blocks with lubricant piped into the shells by rubber hose from reservoirs on the side rails. There was a thermal switch in each pillow block. One day on a long weekend the rubber hose got brittle enough to break and drain all of the oil onto the floor from one pillow block (luckily the one towards the motor, whose bearings provides some support).

The guard force were the only ones there to hear the screeching noise form the bearings, and they didn't know who to call. (They should have, but they didn't. :-)

By Tuesday (long weekend, remember) when the fellow who they should have called arrived, heard the noise, and shut the system down (there was a bypass, at least) that bearing was *hot*.

How hot? Well ... the rollers were the size of 35mm film cassettes, and one which I collected had a lip which *looked* like a 35mm film cassette, smeared off the steel of the bearing -- all blue-black.

The thermal sensors which should have shut this down automatically? They were depending on the oil to conduct the heat from the failing bearing to the sensor -- remember -- the oil in a puddle on the floor? :-)

FWIW -- they replaced both bearings (but not those in the motor, which now that I think of it might have been carrying a lot of the load which the failed bearing should have handled.)

Let's see -- 4' diameter flywheel, about 6" thick, running at

1800 RPM ... If it had broken free, it would have run through the external parts of the air conditioners, and then run through the office section of the computer center across the parking lot. Still -- nobody was supposed to be there on a long weekend anyway. :-)

It was pure luck that it was the bearing towards the motor which went, instead of the one towards the flex coupling and clutch.

Enjoy, DoN.

Reply to
DoN. Nichols

Thanks for your comments. As stated, I want it for the generator. I am hoping that it is 60 Hz, single or 3 phase, that I can drive with my Lister Diesel engine for standby or off grid power.

Bob

Reply to
bob_1fs

There are cases on record where the plain flywheels of steam engines (designed to only store the inertia of 1 revolution) burst with disastrous results. A flywheel burst ranked right up there with a boiler explosion.

[ ... ]

Well ... They could still save money, by improving the power factor seen by the service meter.

Hmm ... the one where I used to work -- used to keep the chem lab exhaust blowers working during a power outage -- was a little different:

motor/generator=flywheel=flex-coupling=clutch=diesel-engine

and when the power failed, and the flywheel cranked the diesel to an instant start, the three-phase motor became the generator.

This is not enough, as proven by what happened to ours. There were big self-aligning roller bearing assemblies in pillow blocks with lubricant piped into the shells by rubber hose from reservoirs on the side rails. There was a thermal switch in each pillow block. One day on a long weekend the rubber hose got brittle enough to break and drain all of the oil onto the floor from one pillow block (luckily the one towards the motor, whose bearings provides some support).

The guard force were the only ones there to hear the screeching noise form the bearings, and they didn't know who to call. (They should have, but they didn't. :-)

By Tuesday (long weekend, remember) when the fellow who they should have called arrived, heard the noise, and shut the system down (there was a bypass, at least) that bearing was *hot*.

How hot? Well ... the rollers were the size of 35mm film cassettes, and one which I collected had a lip which *looked* like a 35mm film cassette, smeared off the steel of the bearing -- all blue-black.

The thermal sensors which should have shut this down automatically? They were depending on the oil to conduct the heat from the failing bearing to the sensor -- remember -- the oil in a puddle on the floor? :-)

FWIW -- they replaced both bearings (but not those in the motor, which now that I think of it might have been carrying a lot of the load which the failed bearing should have handled.)

Let's see -- 4' diameter flywheel, about 6" thick, running at

1800 RPM ... If it had broken free, it would have run through the external parts of the air conditioners, and then run through the office section of the computer center across the parking lot. Still -- nobody was supposed to be there on a long weekend anyway. :-)

It was pure luck that it was the bearing towards the motor which went, instead of the one towards the flex coupling and clutch.

Enjoy, DoN.

Reply to
Robert Swinney

smaller filter capacitors as well.

Reply to
Cydrome Leader

Some standards that were set were blocks away from the water pump or power generation building. Through bricks and then through buildings along the way. Massive turning wheel has tremendous moment of inertia.

Flywheel designers / engineers were made to be qualified like boiler makers. ME and MME grades with in-field training/in-service.

When the power cycle protection types are put into buildings, they are rotated to be in line with an under ground wall or a stopgap of some sort.

Martin

Mart> There are cases on record where the plain flywheels of steam engines (designed

to only store the

ranked right up there with

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Reply to
Martin H. Eastburn

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