# motor any good???



## richerson (Mar 7, 2010)

Hi all,
I can get hold of three of these motors, they are from an old air con system in a commercial building. The rpm looks low so probably need to rewind them. I would like to use them in a mid size car or a small truck. Any advise appreciated. I don't have the sizes of them but they are quite large. ill try and get some measurements next week when i go back to site.


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## kennybobby (Aug 10, 2012)

Can you determine if the fins on the motor are aluminum? Does the unit to the right that it attaches appear to be a big coupling to another shaft, or just some pulleys?


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## richerson (Mar 7, 2010)

Fins are aluminium 

Not 100% sure about the drive. I think it's belt from memory.


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## WSJ (Sep 18, 2008)

A controller with 480 VAC output would need 1,400 VDC input.
Vrms = 0.3535 * Vpp


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## richerson (Mar 7, 2010)

I will rewind it for lower voltage if it's worth using.


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## major (Apr 4, 2008)

richerson said:


> I will rewind it for lower voltage if it's worth using.


See the chore involved with rewinding near the end of this thread: http://www.diyelectriccar.com/forums/showthread.php?t=59659&highlight=roadster 

And FWIW, a 480 V AC drive requires about a 650 to 700 V DC bus.


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## richerson (Mar 7, 2010)

Thank for the info. 

600v pack is possible. But the rpm is low, can I up the rpm on the controller settings or do I need more volts. The motors are free seems a shame not to do anything with them.


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## major (Apr 4, 2008)

richerson said:


> Thank for the info.
> 
> 600v pack is possible. But the rpm is low, can I up the rpm on the controller settings or do I need more volts. The motors are free seems a shame not to do anything with them.


The voltage and winding will limit power even at higher frequency (RPM). I'd say free will cost you too much


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## richerson (Mar 7, 2010)

Thanks Major, 

I think it will cost to much. Oh we'll I'll have to keep searching until something more useable comes along.

Cheers


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## PStechPaul (May 1, 2012)

From what I could read on the nameplate they are 75 kW or 100 HP, and 1470 RPM at 50 Hz so about 1760 RPM at 60 Hz which means 4 poles. Motors that size are probably 480 VAC (or even 575 VAC) but might have dual windings for 230/460. If so, you could connect them for 230V and with a 600 VDC pack you could overclock them for 3500 RPM. Actually they are probably too large and heavy for anything less than a medium size truck. If the size and weight are not a problem you might be able to run it at 230 VAC and 30 Hz which would give you the same rated torque (about 300 lb-ft) but half the power at about 850 RPM, and then go up to 120 Hz for 3500 RPM, same power (about 50 HP), but less torque. 

With the aluminum frame, this motor may be only 500-600 pounds, and similar to this Baldor model:
http://www.baldor.com/products/perfdata.asp?catalog=EM2555T-4&product=AC+Motors&family=General+Purpose%7Cvw_ACMotors_GeneralPurpose

At 25% load, it is still 93% efficient but power factor is poor at 50%. Thus it has a line current of 50 amps at 460V. Running it at 30 Hz and 230V may be even better, and it will easily handle 115 amps which is its rated current at 100% power. If you look through the Baldor catalog there is a page which states that:

Efficiency Savings
Significant energy savings can be achieved when applying Inverter Ready motors such as the Baldor Super-E to centrifugal load applications (fan and centrifugal pump)​
and running at reduced speed taking advantage of the affinity laws where motor load and corresponding energy consumption is reduced by the cube of the speed.


The problem may be getting an appropriate controller at reasonable cost. A standard 230V 50 HP inverter from Baldor is about $10,000 list price, while a 460V version is $8000. But you might find one on eBay or a surplus house for 1/3 to 1/10 the cost. I think it is fairly straightforward to set up a controller for torque rather than speed control, as needed for automotive use. And also you must consider that industrial drives are not designed for a vehicle environment.

If you can get these motors really cheap, and you have the means to transport, store, and install them, you can't go too far wrong. List price for 100 HP motors ranges from $5000 to $15,000 and on eBay they are about $1000-$3000. Scrap value is probably at least $500;


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## richerson (Mar 7, 2010)

Thanks for all the info, food for thought. I'll be back on site tomorrow I need to make sure of the specs and the sizes. I think they are a bit to large for what I want. If I'm lucky I might find a slightly smaller motor there.

If it duel wound, would an inverter like this work?

http://www.ebay.co.uk/itm/New-Hitac...494?pt=LH_DefaultDomain_0&hash=item25585b1296

Cheers


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## kennybobby (Aug 10, 2012)

Open the cover plate on the motor to see the wiring terminals and maybe a schematic pasted on the inside. The label you posted looked like it was for an eddy current speed control and not the motor. Yes an inverter such as the Hitachi could be used to run it.


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## richerson (Mar 7, 2010)

Ok went back there today and its to big for what i want. I did find two other smaller motors they are rated at 11kw and are 600mm l x 300mm d. I did find a bigger motor but weighed 1700kg not even sure i could get that out the building.


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## major (Apr 4, 2008)

richerson said:


> Ok went back there today and its to big for what i want. I did find two other smaller motors they are rated at 11kw and are 600mm l x 300mm d. I did find a bigger motor but weighed 1700kg not even sure i could get that out the building.


Why are you looking at AC motors


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## richerson (Mar 7, 2010)

These are free thats all, could go dc or ac.


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