# 25hp 166lbs AC motor for $789



## major (Apr 4, 2008)

I recommend going with a 4 pole motor.

Regards,

major


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## etischer (Jun 16, 2008)

I'd have to assume the motor is a 4 pole. My preference would be a 6 pole for more low speed torque. Max speed is typically limited by bearings, so you get more torque at low speed and same horsepower at high speed. 

The leeson motors Ive used in the past were crap, they ran incredibly hot, to the point you could smell the paint burning and you couldn't touch them. I wouldn't count on running 200% motor current if that's what you're thinking =)

The motor is probably not inverter duty rated. It is expecting a 230v sine wave, a VFD will be putting out a 300vdc pwm signal simulating a sine wave. Inverter duty rated motors have insulation rated for the higher voltage required. 

I'd go with a marathon black max or blue chip motor. 

http://web5.automationdirect.com/static/specs/motorsblackmax.pdf


Black max is $2000 for a 230v/460 inverter duty rated motor. 
1000:1 constant torque ratio... meaning same torque at 2 rpm as 2000 rpm. You can probably pick one up on ebay for 1/4 that price. 
They are also made with an extruded aluminum frame with heat sink fins.

Blue chip is $1400 for the same motor, but only 20:1 constant torque and cast iron.


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## OHM (Jun 30, 2008)

Do you know which Leeson motors gave you these issues? The reason I ask is because there are 1000s of them and this motor I specified is less than halve the weight of the Black Max ones and can operate 230 or 460v. I will try to get more info but it makes a good base if it can really produce 25hp at 166lbs for under 800 dollars. In regards to the black max, anything over 300lbs is quite porky and the more commonly avail. in Oz: Baldor or ABB equivalents are still much lighter.

Also a 15hp Leeson 140689 is 100lbs quite a featherweight.

*Application *- Designed for inverter or vector applications where up to a 2000:1 constant torque speed range is required. Typical uses include: material handling, machine tools, conveyors, crane and hoist, metal processing, test stands, pumps, compressors, textile processing, and other industrial machinery installed in dusty of dirty environments. 

*Horse Power:* 15 *RPM:* 3450 *Voltage:* 208/230/460 *Phase:* THREE *Enclosure:* ODP


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## major (Apr 4, 2008)

etischer said:


> I'd have to assume the motor is a 4 pole.


Hey etischer,

Rated speed (at 60 Hz) is just shy of 3600 RPM. So it is a 2 pole motor.

Regards,

major


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## Jim (Jun 1, 2008)

For what it's worth, I'm understand all the Leeson 3 phase motors over 1 Hp are now inverter rated. They also have their premium efficiency units (watt saver as I recall) 

I can't verify it, but I would assume that all the major motor manufactures would make any of their "new" motors inverter rated with the popularity of the VFD units already.


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## etischer (Jun 16, 2008)

A motors horsepower generally boils down to how much heat it can dissipate. 

I've found all the leeson motors I've used (all 1hp or less) run extremely hot and I've have had a 50% failure rate within a year. I was running these motors with virtually no load which is even more alarming. 

Almost all motors above 1/3 hp are dual voltage 230/460. A motor will say "Inverter duty rated" if it is rated. This is something you generally have to pay extra for. Motors designed to run across the line, such as single speed pumps would not be Inverter rated. You get what you pay for, cost and weight. Leeson motors are low cost and low weight. If you want lots of power in a small package, get a water cooled motor.


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## OHM (Jun 30, 2008)

I see but is it worth shooting the duck before its had a chance to fly?

It would be interesting to see if this Leeson lightweight is worthwhile trying out and surely it can be externally fan cooled and even fins added
on the armature for better cooling, no?


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## Jim (Jun 1, 2008)

The other thing that I've been batting around is, removing the fan altogether and then wraping the motor with some sort of thermal transfer gel followed by a layer of flexable copper or aluminum tubing that could then be routed to a rad or heater core for cabin heat.

This may not be practical if it takes to long for a motor to build up enough heat. In particuar town driving where it's not under real big loads. Just an idea.


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## etischer (Jun 16, 2008)

from the pics, it doesn't look like the motor has a fan. Wrapping coolant lines around the motor sounds like a solid plan. There are probably sections of the motor casing you can tap holes into without damage to the internal wiring, this will help clamp your tubing to the motor. You might try epoxy instead of thermal grease. Thermal grease may have a higher thermal conductance, but a flexible epoxy would probably give you more contact. If you're good with a welder, maybe even weld an aluminum water jacket. 





Jim said:


> The other thing that I've been batting around is, removing the fan altogether and then wraping the motor with some sort of thermal transfer gel followed by a layer of flexable copper or aluminum tubing that could then be routed to a rad or heater core for cabin heat.
> 
> This may not be practical if it takes to long for a motor to build up enough heat. In particuar town driving where it's not under real big loads. Just an idea.


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## Bill318 (Aug 24, 2008)

I would have to agree with the others in that a 4-pole motor may be a better fit for an EV. I have also been looking at commercial motors and limited my list to TEFC aluminum frame motors. ABB makes some nice ones but I'm also interested in the US motor U25E2DC which can be had for about $1,200 US new.

These motors can be coupled to a commercial drive like the Danfoss or Hitachi. I have been looking at the Hitachi SJ300-550HFU. The real inexpensive DuraPulse GS3-4075 drive looks promising but will have no warranty or support if connected to a DC bus. Still wating to hear if someone successfully connects one of the GS3's to a DC bus. In any event to use these drives requires a battery bank of around 600V. This does not bother me as once you are over 50V DC, it is all lethal and deserves much respect and careful system design.

Bill


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## aeroscott (Jan 5, 2008)

OHM said:


> Just wondering if this motor would be suitable for an EV conversion as its the lightest industrial motor I could find for its rating.
> 
> Leeson 801057
> 
> ...


look at frame size , weight , forget the hp . if that motor had 4 poles (instead of 2 poles )it would be 15 hp and would be a stronger more powerful at 1800 , 3500 @ 120 hz. these motor rating are at 60 hz. we will be running at 1 to 400 hz. So the more poles the more torque . but to many poles will limit max rpm power / efficiency . Tesla uses 4 poles and 12000 rpm . So say we can max these motors at 6000 to 8000 . that would mean 8 poles or 6 poles . 8 pole motor 256 frame would be rated at 7.5 hp . sounds weak but it won't be .


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## Bill318 (Aug 24, 2008)

From what I have read on most commercial motors, it is not a good idea to run them past 4,000 RPM or so. Otherwise the rotors may not survive and the bearing life is reduced. Also the TEFC motor fans may be a bit loud or fly apart at 6 ~ 8K. In any event it would be a good idea to check with the manufacturer on the suggested upper RPM limit for a particular motor.

My preference is to run a 25HP 60Hz/230V/1725 RPM motor up to 50HP by feeding it with a 460V drive topping out at 120Hz/460V/3450 RPM.Would like to know if they make a flex fan (or similar) for TEFC motors that spend their life at low and high RPMs.

Bill


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## etischer (Jun 16, 2008)

Bill318 said:


> Also the TEFC motor fans may be a bit loud or fly apart at 6 ~ 8K. In any event it would be a good idea to check with the manufacturer on the suggested upper RPM limit for a particular motor.
> 
> Bill


Good point, My 3hp TEFC motor is super loud at only 2000rpm. The fan can be removed obviously, and would be required if exceeding the max speed.


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## aeroscott (Jan 5, 2008)

get rid of the fan put a ducted electric fan on . cut holes in the end plates of the motor and duct fan air through the motor . worst heat is at very low rpm . the rotor can get very hot .


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## OHM (Jun 30, 2008)

How about 20 poles? like in this little monster?!!!

http://www.plettenberg-motoren.com/UK/Motoren/aussen/Predator37/Motor.htm

Cant be used for EVs but a good example of what can be achieved

1900 grams and 15kw WTF!!!!!


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