Looking for a motor

Telco
Telco Solar Expert Posts: 201 ✭✭✭✭✭
I need to find an electric motor, approximately 2HP, that operates off 12V and spins 1000 - 2000RPM. Any suggestions on where I might find such a beast? Figured a solar power site might be the best place to find this as you guys mess with a lot of 12V items that are normally run by 120V. Been searching since last week, just not finding what I'm needing although it looks like a trolling motor might be close. Thanks.

Forgot to add, usage will be intermittent on/off, plan to use it to drive the HVAC compressor on my truck. I've got some changes upcoming to the truck that requires I move the compressor off the engine, elsewhere in the truck. Eventually the 12V motor would be replaced with a 120V motor, but for now would like to do a 12V. If it turns out to not be possible I can do a 120V/inverter setup but I'd prefer to keep it simple for now.

Comments

  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Looking for a motor

    eBay has lots of DC motors ... btw, 2HP will be something around ~2+kw , or ~250 amps ... How are you going to power the motor?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Looking for a motor

    Sounds like a complex problem... Using a simple "brushed" DC motor is going to saddle you with brush maintenance and RF noise.

    For a motor that size, you would probably want to use an AC motor and a DC to AC motor controller (think electric car type system)...

    In any case, you are probably talking about close to several hundred amps (starting/running will be less) to run 2 HP from 12 VDC...

    Sounds like, to me, you are almost at the point where you do the 120/240 VAC system with an inverter and/or dedicated genset (might even be more fuel efficient than using your truck's alternator to power this "beast"). Or try to find a used refrigeration unit from a truck/trailer that runs from diesel or some other fuel...

    You might find something from a wrecked Hybrid (I think--that a Toyota Prius uses some sort of electric A/C pump--don't know if it is large enough and if it is compatible with your refrigerant system, how much it is integrated with the Prius computers, etc...)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Looking for a motor

    Thats going to be some electric motor & control. I think I've heard a automotive AC unit is 5hp drag.

    I'd start thinking either tap off your power steering pump, and run a hydraulic motor to power it, or maybe get a used Refer Unit. What are you going to do for the condenser, leave it in front of the radiator, in the factory location ?
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  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: Looking for a motor

    Yep, from what I've been seeing it may be more than I'll be able to do on 12V. Whatever I use would be powered by the vehicle alternator, which is currently a 120 amp unit. Also exploring the possibility of using a dedicated electrical compressor like a fridge or house AC unit. This project is at the beginning so I've got no set requirements other than it must be run off electricity generated by the truck. Eventually I hope to have the whole vehicle powered off electricity. And, eventually there may be no power steering so I don't want to have to depend on it being there to run other systems. I intend on leaving the condenser up front in the stock location.

    This fellow's my inspiration. Look at his innovative air conditioner and heater solutions, he actually used a miniature version of an electric hot water heater with tank to heat the car. The water heater feeds the heater core just like the ICE did. Thanks for the many responses, starting to rethink the 12V motor for this.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Looking for a motor

    hmmm. don't know why you didn't put this into the 'looking for' sticky. anyhow, have you thought of a starter motor?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Looking for a motor

    My concerns with a starter motor is that the cooling, brushes and bearings (if they are not just bushings) are not designed for continuous duty---after a couple of minutes of "full load", the motor will over heat... And after a few hours the brushes will be worn out and the commutator needing to be turned.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Looking for a motor

    If you plan on running it for more than a minute at a time, forget this idea, you'll end up with a dead battery in very short order.
    That, + the fact that it would be more energy efficient by far to belt drive the comp directly off the engine.
    Good luck
  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: Looking for a motor

    Neil - Sorry, didn't see a looking for sticky. I did see the used parts sticky at the top of this post, but since I'm not sure what exactly I'm looking for here this wouldn't apply to a parts bulletin. I did consider a starter motor, but wrote it off for the reasons BB posted.

    Wayne - An HVAC system properly set up typically runs for about 10-30 seconds every minute to minute and a half. Should not kill my electrical system, and I can always jump up to a 200 amp continuous duty alternator if necessary. Eventually this vehicle will be all electric anyway, in the meantime I need to start doing the work piecemeal. I also have to question which would be more efficient as I'm constantly told that going from mechanical fans to electric fans costs the same in power, the savings is in that the electric is not on all the time, yet in the heat of summer when the fans are on full blast (the fan is the correct size but the radiator is marginal, needs replacing before next summer) I still have a drastic improvement in mileage and power over what the mechanical fan did in the same conditions. I was hoping that I could locate a 12V motor that would do the job without inverter loss, but I'm thinking now that this is not to be. Might have to set up a small inverter and go 120V on this. Bummer.


    Thanks to everyone on their posts, I appreciate the info. I think I know what I need to do here now, will start trying to source out an electric compressor now. Thanks for the Prius tip, will check into that. I'll also be sure to post back with the completed project along with how much drag the setup puts on the truck. I'll even try to get dyno readings to see what the difference is.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Looking for a motor

    "Forgot to add, usage will be intermittent on/off, plan to use it to drive the HVAC compressor on my truck."

    i was going by what you said above that it wasn't to be continuous service, but if you don't think this is suitable then i suggest a 120vac motor as there aren't any more common of a high power 12v motor than these that i am aware of.