Author Topic: DIY Generator questions  (Read 2639 times)

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Offline Neracoal

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DIY Generator questions
« on: March 18, 2014, 02:51:55 PM »
I have been lurking for awhile now.

I was at a local scrap yard today and came across a permanent magnet motor. I have been wanting to play around with a DIY generator for some time now.

Anyways i ended up buying it. it is very heavy(70 lbs) it says 220 volt dc 17.0 amps and 4 hp is this something that can be used or is it to big?

i can spin it by hand and get 25-30 volts ac out of it np at all. if i put my meter on dc i can get about 7-10 volts. no load of coarse.

i assume after i figure out how i want to spin it then i wire the + and - into a charge controller and then to a battery or a bank of batteries.

I want to use it to recharge batteries at the cabin.

what would you guess i could get out of this at say low rpms (say 250) and at high rpms (say 2500)?

Any thoughts and help would be greatly helpful.

http://www.jwarfieldelectric.com/com....html?Itemid=0

4 horsepower 17amp 220voltz DCContinuous Duty Electric motor


Offline bj

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Re: DIY Generator questions
« Reply #1 on: March 19, 2014, 06:24:49 AM »
Interesting for sure.  There will be many questions, before good answers.  RPM will depend on what
battery voltage you settle on.
I am pretty sure you can make it work, but not sure of what your options are to drive it.
"Even a blind squirrel will find an acorn once in a while"
bj

Offline Norm

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Re: DIY Generator questions
« Reply #2 on: March 19, 2014, 10:34:02 AM »
Put a hand crank on it hook it up to a 12 volt battery and crank it. See if you
can crank it fast enough to charge the battery about 13volts or so .
   If you can keep an eye on the second hand of a clock and count how many
turns you are spinning it.
   If you can't spin it fast enough, repeat procedure with a 6 volt battery.
   Now after you have determined how fast you have to spin it we can go
from there.
    When you have got that now you can figure out a practical speed to
spin it , and what would be the most practical way to spin it, a VAWT
comes to mind for beginners .......where the generator can be on the ground
     I'm suggesting that you start small even if you are using a big
generator .
     If you start small and fail , it's less of  a heartbreak . ;)

Hope this helps ......anyway get started and there will be plenty of us to
give you helpful advice and suggestions.
    Have Fun !
Norm.
Let me know how fast you have to spin it , I'm dying of curiosity !

Offline Bub73

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Re: DIY Generator questions
« Reply #3 on: March 19, 2014, 11:30:09 AM »
roughly 151 rpm for 12 volt charge rate
 350 for 24 volt
looks like it is doable

Offline Norm

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Re: DIY Generator questions
« Reply #4 on: March 19, 2014, 11:49:56 AM »
yay!  Glad to hear it.....keep us posted on your progress .
 
     Do you already have a battery bank?
Norm.

Offline ChrisOlson

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Re: DIY Generator questions
« Reply #5 on: July 12, 2014, 02:13:42 PM »
4 horsepower 17amp 220voltz DCContinuous Duty Electric motor

Old thread.  But if you engine-drive that motor you'll get (4hp = 2.9 kW) @ 220VDC from it.  And it will require about 3.7 kW, or 5 hp, to drive it.  It will be useless on a 24V system.  At 17A max rating on the winding you will only get about 500 watts from it.

Offline Burnit0017

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Re: DIY Generator questions
« Reply #6 on: July 14, 2014, 02:49:36 PM »
Hi, would a MPPT circuit help???

Offline ChrisOlson

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Re: DIY Generator questions
« Reply #7 on: July 14, 2014, 03:23:33 PM »
Yes.  Even on 48V MPPT would be the only logical solution to get any decent power from it.  And it would require a controller capable of 250V to be able to use it at rated speed, driven by an engine.  The MidNite Classic 250 would work excellent on it.  I had an engine driven 140VDC generator here for awhile and used a Classic 150 with it.  I used the hydro mode and it worked great.  In theory, you can also program a wind curve for an engine driven DC generator and be able to operate the generator at various speeds and the controller would adjust the Vmp automatically, based on amps to the battery.

Offline Burnit0017

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Re: DIY Generator questions
« Reply #8 on: July 14, 2014, 03:57:39 PM »
Hi, thanks for the info. Morning Star is also working on a MPPT control that should work with a PMA. At this time is only available as bata software. What does Vmp stand for, does it only apply to the classic software?

Offline rossw

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Re: DIY Generator questions
« Reply #9 on: July 14, 2014, 04:39:06 PM »
What does Vmp stand for, does it only apply to the classic software?

V for Voltage.
Subscript mp for "Maximum Power". That is, what voltage does it produce it's maximum POWER OUT at.
(Not everything is linear. With a battery and a resistor, the power goes up as the voltage does. With many things, there's a sweet spot where the voltage can increase, but the current decreases more, thus higher voltage doesn't necessarily mean higher power)

Offline ChrisOlson

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Re: DIY Generator questions
« Reply #10 on: July 14, 2014, 04:54:55 PM »
Hi, thanks for the info. Morning Star is also working on a MPPT control that should work with a PMA. At this time is only available as bata software. What does Vmp stand for, does it only apply to the classic software?

The TriStar MPPT controllers have actually gone production now for wind and hydro power.  But the TriStar TS-MPPT60-600V controller is very expensive - around $1,100.  I would suggest using a Classic 250 on it.  The Classic is better tested, is a proven unit and the support and warranty on it is second to none.

Offline Burnit0017

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Re: DIY Generator questions
« Reply #11 on: July 14, 2014, 05:37:51 PM »
Hi, thanks to all for the info.