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big enough electric motor?

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LAN_403

Quantum Singularity

Tue Aug 01 2006, 02:03AM

Registered Member #158 Joined: Sun Feb 12 2006, 09:53PM
Location: Central Ohio
Posts: 282

Just thought I would post a pic of this since you dont see motors this big just every day, not that it is the biggest one there, just the biggest I could take a pic of the nameplate.

Its from a powerplant I toured the other day. Cant remember for sure, think it was one of the feedwater pumps. Does anyone else here work for a power utility co?

...

Tue Aug 01 2006, 02:49AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

well that is quite a motor

At a mere 5 tons, how big is it? Seems like a 5ton block of copper would only be like .5m^2

Impossibly small for a 3MW motor...

Arround here the feed to the building is a 3 phase 480v 1ka feed, (1.2MW) so no motors that big

dan

Tue Aug 01 2006, 05:33AM

Registered Member #223 Joined: Mon Feb 20 2006, 06:42PM
Location: Ottawa, Ontario, Canada
Posts: 125

Maybe we sould have a guess the size of the motor contest!

Well 9160lbs = ~4.08 tons.. Plus it's not going to be completely solid copper. (still some air in there) and the motor is going to be mostly aluminum & steel for the rotor and staytor laminents. Plus once you convert the volume from a cube into a cylinder it's going to be pretty big.

Edit - here is my entry:
20% copper, 20%aluminum, 55% steal, and 5% air by volume

Cu = 8.23g/cm^3
Al = 2.70g/cm^3
Steal = 7.85g/cm^3
Air = nil (airâ€™s mass will be ignored)

Motor density = (8.22 * 20%) + (2.70 * 20%) + (7.85 * 55%) = 6.502g/cm^3
= 0.0143344563lbs/cm^3

Motor volume = 9160lbs / 0.0143344563 lbs/cm^3
= 639019cm^3 = ~0.64m^3

Still sounds way too small but lets continue. I'll assume the motor is 1 meter long but thats just a shot in the dark.

R = Sqrt(V/(pi*h)) = Sqrt(639019cm^3 /(pi*(100cm))) = ~45cm

So I recon that motor is a meter long and 0.9 meters in diameter. So yeah itâ€™s big. I wouldn't want to drop it on my foot ;)

...

Tue Aug 01 2006, 06:00AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

Well... Even if it was just a block of aluminum it would be about 2m^2, or a tube 1m in diameter and 3m long... Still seems pretty small for a device that is putting out 2000hp continously

dan

Tue Aug 01 2006, 07:25AM

Registered Member #223 Joined: Mon Feb 20 2006, 06:42PM
Location: Ottawa, Ontario, Canada
Posts: 125

Well 2000HP doesn't mean a whole lot.. You could be moving 66,000,000lbs one foot in 1 min or moving 1 lbs 66 million feet in 1 min. Some where in between you'll find something resonable.

but yeah 2000hp is 1492kW! (Thats only the output power!) Good thing they are a power plant because this single motor probably uses enough power in one hour to power my house for a month or two.

Marko

Tue Aug 01 2006, 12:15PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

2300 volts 426 amps for 3 phase supply...
Nice pick from westinghouse...

''caution: before installing and operating read instructions''

Avalanche

Tue Aug 01 2006, 01:22PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

haha, I hope it says "bolt down to a secure surface before throwing the switch" in there somewhere.

It would probably destroy everything within a 10 meter radius if you forgot that

robert

Tue Aug 01 2006, 09:51PM

Registered Member #188 Joined: Thu Feb 16 2006, 05:18PM
Location:
Posts: 67

Small Motor:

4mm diameter, about 20mm long.
Weighs less then 2g

Rated voltage 1.2v, rated current 10mA.

1154469243 188 FT1630 1

Sorry pic didnt work on the 1st try because the forum didnt take a .jpeg file.

[Edit: Maximum width 400 pixels...]

Marko

Tue Aug 01 2006, 10:10PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Very 1337 motor robert

maybe it could be used for some kind of ultra-light solar aircraft or something
(just posting crap as always)^^

Quantum Singularity

Tue Aug 01 2006, 10:43PM

Registered Member #158 Joined: Sun Feb 12 2006, 09:53PM
Location: Central Ohio
Posts: 282

Sorry guys I guess I didnt get a pic of the actual motor, its not all that big size-wise. Think it was probably around 1 meter long maybe a bit more. Even the generators on the turbines arent too big, I think the largest one at that plant was a 500-ish megawatt generator and it was maybe 3-4 meters long... thats ballpark since its just from memory. Its surprising how much power it actually takes to run a large coal powerplant... the big 1300MW plants usually have around 100MW of station load. Even when there not actually producing power they can be drawing 1/3 of that load too since several things need to stay active - like the actual turbines still turn on 'turning gear' so they dont warp due to unequal heat (hot air at the top, cooler at the bottom).

I didnt get to actually see one but the largest motors are the FD fans (forced draft) which take the hot air that comes out of the boiler and blows it back in through the coal pulverizers, they are in the neighborhood of 10,000HP give or take.

The scale of things at a power plant is huge... I had a pretty good knowledge of how they work and what to excpect but when I actually got there I was blown away (and it was not a large plant either). I mean the boiler (water-walled chamber were the coil is burnt) itself could probably fit a small 10-story building inside it... and the whole thing is suspended from above so to allow for heat expansion. I got to go inside of the boiler too, since it was being rebuilt. Definatley worth while if you ever get the chance to tour one. But I wouldnt want to work there... dirty, and lots of bad stories, probably safer at a nuke plant lol!

EDIT> How come you didnt take a pic of the name plate on that little motor?

Thats one tiny motor!

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