Help Finding 24V motor

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My team builds prototype machines...this particular application is giving me a headache. Any help would be GREATLY appreciated!

Looking for:

Variable Speed Electric Motor and Controller
24V
Minimum 3.5 kW (~5 hp)
Must be able to go up to 2000 rpm (would prefer maximum rpm of 3500-4000)
 
That's a pretty tough spec which is probably why it's giving you a headache. Usually for something like that, you like higher voltage like 240v because those motors last longer than 120v. Let us know if you find it.
 
Originally Posted by meep
5HP from 24V is crazy. 3.6KW at 24V is like 150 amps. That's starter motor territory.


There are many in off-highway equipment...the tricky part is the "variable" part.
Can you drive ANY 24V DC motor as variable with a PWM? I have one in hand that is being driven on/off, but I don't know if I can drive it variably.

I am also looking into golf cart motors...many of them are much more powerful than I need...but start at 36V-48V
If I have a 48V golf cart motor, can I drive it with a variable 24V source? I've found a variable golf cart motor that is rated for 10hp at 48V - can I expect to get 5hp driving it at 24V? My simple DC equations I do remember tell me I can...?

Out of all the classes from engineering school, this is the one I remember the least about.
 
The tech exists for home HVAC - PSC/ECM motors work on that same principle but using AC and at line voltage. Almost like the motors inside of a Prius.

All the stuff I'm seeing via Google are 48V DC motors from China that can put out that power. What the heck are you building?
 
Yes you can drive any brush-type motor with PWM to slow it down. The PWM controller is a generic item you'd select based on volts and amps.

Running a motor on less than rated voltage the hp is likely to drop by at least voltage squared, i.e. 1/4 the power for 1/2 the voltage.
 
Originally Posted by nthach


All the stuff I'm seeing via Google are 48V DC motors from China that can put out that power. What the heck are you building?


Sadly I can't share that right now.
 
Originally Posted by DriveHard
Originally Posted by nthach


All the stuff I'm seeing via Google are 48V DC motors from China that can put out that power. What the heck are you building?


Sadly I can't share that right now.


If it's something classified or proprietary, you presumably have better resources at your disposal than BITOG... right?
 
Originally Posted by mk378
Yes you can drive any brush-type motor with PWM to slow it down. The PWM controller is a generic item you'd select based on volts and amps.

Running a motor on less than rated voltage the hp is likely to drop by at least voltage squared, i.e. 1/4 the power for 1/2 the voltage.

Another idea would be using a DC controller to control an AC motor, which are much more plentiful.
 
you will want a GM BAS+ (eAssist) Motor Generator from one of those mild hybrid

it's 20HP 44ft lb torque it will need to be water cooled though

36 volts
 
Last edited:
With that much information given its pretty hard to find anything that would be remotely helpful to you.
 
Originally Posted by Ethan1
Originally Posted by DriveHard
Originally Posted by nthach


All the stuff I'm seeing via Google are 48V DC motors from China that can put out that power. What the heck are you building?


Sadly I can't share that right now.


If it's something classified or proprietary, you presumably have better resources at your disposal than BITOG... right?


I do...but I have been surprised at some of the knowledge on this forum. It often surpasses some of the "experts" I interact with.
 
Originally Posted by Rand
With that much information given its pretty hard to find anything that would be remotely helpful to you.


What more do you want to know?
 
Even if you can find a motor, that 150 amp number is hard to get around from a systems perspective. What's the proposed duty cycle/load factor of the setup? With that much current, everything in the current path tends toward looking like a space heater, if not a fuse. Things like resistance of terminal connections matter, not to mention the heinous requirements of any relays/contactors, OCPD, etc. You get power dissipation EVERYWHERE.

24V 150A, or 240V 15A, I know what I'd be shooting for. Voltage is not your enemy in this case.

Love to see what power supply is backing this as well.

You might try looking for 3-phase motor/controller combos that take DC power input. I used one of these (96V nominal) successfully in a Formula Hybrid car in college. Speed control is a simple pot input.
 
Originally Posted by benjayman227
Even if you can find a motor, that 150 amp number is hard to get around from a systems perspective. What's the proposed duty cycle/load factor of the setup? With that much current, everything in the current path tends toward looking like a space heater, if not a fuse. Things like resistance of terminal connections matter, not to mention the heinous requirements of any relays/contactors, OCPD, etc. You get power dissipation EVERYWHERE.

24V 150A, or 240V 15A, I know what I'd be shooting for. Voltage is not your enemy in this case.

Love to see what power supply is backing this as well.

You might try looking for 3-phase motor/controller combos that take DC power input. I used one of these (96V nominal) successfully in a Formula Hybrid car in college. Speed control is a simple pot input.


The industry this machine operates in is standardized as 24V - source is a bank of lead acid batteries
The machine today operates between 150-200 amps...but as on/off
Our goal is to distribute the power between multiple sources instead of one source, and make everything variable instead of on/off
Duty cycle is intermittent at best. The machine spends much of its life sitting still. The particular function of the machine I am working on will operate for 45-60 seconds at best, then have plenty of time to resume to ambient.
Peak load is about 150 amps to get the load going...then settles to 80-100 amps.
 
Originally Posted by mk378
... Running a motor on less than rated voltage the hp is likely to drop by at least voltage squared, i.e. 1/4 the power for 1/2 the voltage.
Yes. About half the starting torque and half the no-load speed, too, for a basic brush motor.
 
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