Author Topic: Have I created a monster (of sorts) ?  (Read 3689 times)

0 Members and 1 Guest are viewing this topic.

Harold in CR

  • Hero Member
  • *****
  • Posts: 564
Have I created a monster (of sorts) ?
« on: May 16, 2017, 02:58:52 PM »

 Quite a while ago, I bought a new 3 phase 1.5 HP MagneTek motor 120/208V for a wind turbine build. Zubbly had recommended these in his postings. I found to get any useful voltage out of it, I had to connect capacitors to each phase, and once the spinning rotor got the capacitors up to a certain voltage, the motor would cut in and produce usable voltage. Also, as the rotor spun down, if it got too low a voltage, the output cut out and had to wait for the rotor to again charge the caps and then it would cut in. Not so great for a wind turbine.

 SO, I went back through Zubbly's posts and built the cage design with small magnets. I read the posts over and over and then bought magnets, to copy his design. I pulled the rotor and turned it down on my home made metal lathe. All I had for measuring was an imperial ?/metric tape and a dial caliper and normal manual calipers to check OD of things. I did the math according to Zubbly but, later found out he was building a cage/rotor for a 4HP motor. My magnets were too big in diameter, Zubbly used 1/2" X 3/8 long in a 3 wide X 7 long configuration.

 Now, I can't do the 3 wide X 7 long design, so, I decided to do a 2 wide X 5 long. I managed to cut the rotor down to be able to use the 3/8" length, so the magnets would clear the stator teeth. I won't mention how I measured the stator ID, since I had no ID measurement tools. I went ahead and built the fiberglass cage and drilled the magnet holes. Then, I placed 8 magnets in the cage at top and bottom of the sets of holes. Sliding the rotor inside the stator was nothing but frustration, BUT, I found I did have the clearance correct to proceed with populating the cage. With the end caps in place, I could turn the rotor without hitting stator teeth. I could get over 9V just by twist spinning the shaft. The motor was propped up on a metal can so the tail shaft would not hit the workbench. I had glued the magnets to the cage with whiteglue so they would not jump out of the cage holes and get out of alignment inside the motor.

 I wrapped a string around the shaft and spun the rotor and got varying voltages up to 17+ v. This was encouraging, so, I did the dreadful deed and managed to get all 40 magnets into the cage holes and centered the cage as best I could on the rotor. I then sealed up the back end of the rotor and poured the resin in.

 Afer the resin kicked off I cleaned off the tape and extra resin from slight leakage and placed the rotor inside the motor and put the front end cap on. NOW, I can get over 47V by placing my hands on opposite sides of the shaft and spinning it up by the fire starter method, somewhat.  :o

 Question is, is this going to be impossible to use as a wind turbine trying to charge a 24V battery system ?? I do have a 90A-bridge rectifier hooked to all 3 phases and feeding my VOM. Maybe a load would be more realistic way to check voltage ? Also, what kind of amperage should I expect to get ? This is a 4-6 Amp rated motor. Will the battery load/controller regulate the voltage and allow the amperage to rise up to, say, 20-30 amps or so ? I realize there is a lot more to this, but, I want to see what I have before trying new things, just in case what I have does work  ::) ::)

 If any of y'all can follow this post, I would appreciate ALL aspects of what I have and if this thing is usable.

 Thanks,  Harold

 

Mary B

  • Administrator
  • SuperHero Member
  • *****
  • Posts: 3169
Re: Have I created a monster (of sorts) ?
« Reply #1 on: May 16, 2017, 06:36:39 PM »
Should work fine, I would feed an MPPT controller but otherwise the battery will clamp the voltage lower.

Harold in CR

  • Hero Member
  • *****
  • Posts: 564
Re: Have I created a monster (of sorts) ?
« Reply #2 on: May 16, 2017, 07:06:27 PM »

 Thanks Mary. That is what I thought. My brain is not operating correctly. Sometimes I get confused and just can't remember common things. Everyone please accept my apologies for asking these simple questions.

 Thank you

SparWeb

  • Global Moderator
  • Super Hero Member Plus
  • *****
  • Posts: 5452
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Have I created a monster (of sorts) ?
« Reply #3 on: May 20, 2017, 12:36:31 AM »
Hey, I'm the king of stating the plainly obvious sometimes.

Are you interested in investigating the wiring schema in the motor?  Just in case it's currently wired in Star, you could reconnect in Wye and adjust your voltage/speed range by a factor of 1.7.  Depending on what wires are permanently connected in the stator, you might have to dig around and be willing to cut + solder some.  Once you find the right connection though, it's not that hard.

I would get a more scientific measurement of speed before making any other judgements.  You may have what you need to rig up something temporary to drive it at a constant speed (I used a drill press to do that, once.)
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

SparWeb

  • Global Moderator
  • Super Hero Member Plus
  • *****
  • Posts: 5452
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Have I created a monster (of sorts) ?
« Reply #4 on: May 20, 2017, 12:37:38 AM »
... though not very scientific...
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

Harold in CR

  • Hero Member
  • *****
  • Posts: 564
Re: Have I created a monster (of sorts) ?
« Reply #5 on: May 20, 2017, 03:01:18 PM »

 
Quote
Just in case it's currently wired in Star, you could reconnect in Wye

Isn't wye and star actually the same thing ?  ;D ;)

 I had planned on sitting it on the lands of my metal lathe that has a set of step pulleys on it.

 However, I broke my lathe this morning while balancing the rotor.  :-[ :'(

 Therefore, I ain't about to mess with windings.  ::) :)

JW

  • Development Manager
  • Super Hero Member Plus
  • *****
  • Posts: 4019
  • Country: us
    • Flashsteam.com
Re: Have I created a monster (of sorts) ?
« Reply #6 on: May 20, 2017, 03:59:32 PM »
Quote
Isn't wye and star actually the same thing ?  ;D ;)

wye uses the neutral and star doe's not, you could say the star connection is more similar to delta.

SparWeb

  • Global Moderator
  • Super Hero Member Plus
  • *****
  • Posts: 5452
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Have I created a monster (of sorts) ?
« Reply #7 on: May 20, 2017, 04:25:59 PM »
Doh!     :-[
I meant DELTA!
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

oztules

  • Hero Member
  • *****
  • Posts: 1477
  • Country: aq
  • Village idiot
Re: Have I created a monster (of sorts) ?
« Reply #8 on: May 20, 2017, 06:31:22 PM »
Star and Wye are the same thing... different in name only. Neutral is at the junction of the three phase coils.
In Delta no such junction exists... it is totally different for the following reasons.

Star has a phase voltage near 1.7 times the coil voltage
Wye has a phase voltage near 1.7 times the coil voltage
Star has  a  coil voltage about .58 of the phase voltage
Wye has a coil voltage about .58 of the phase voltage
The Wye or star junction point is approx .58 of the phase voltage

Delta has the coil voltage = phase voltage....totally at odds with the star or Wye situation..... and there lies the main difference for this application.


.........oztules
Flinders Island Australia

Harold in CR

  • Hero Member
  • *****
  • Posts: 564
Re: Have I created a monster (of sorts) ?
« Reply #9 on: May 20, 2017, 07:41:37 PM »
 :o ??? ???
 Y'all are confoozin me. I have 3 wires at the motor connection box with a 90A 3 phase bridge rectifier that gives me + /- readings.  This is delta, correct ??

 I would have to dig out the 3 coil junction to get to the neutral point. Correct ?

 From my lineman experience, up the poles, We had a single line on top and another line below that, that was grounded. That gave us 7200V phase to ground and would give you 7200V in hand if you broke the neutral. Delta was just simply phase to phase and wouldn't hit you so hard if you got stoopid.

 Wye was rural lines and Delta was close to towns/cities. I knew nothing about motors except all were single phase unless there was 2-3 transformers on the pole OR an RO tub, which was a 3 phase high side and 4 low voltage lines with one being a wild leg.
 Now, one day we changed out a 3 phase delta transformer bank and the factory had a conniption. All the motors were running backwards. We had to change the taps inside all 3 transformers and use a rotation meter before we could go back online.

 I don't think I want to go into the motor at this point..
« Last Edit: May 20, 2017, 07:47:18 PM by Harold in CR »

SparWeb

  • Global Moderator
  • Super Hero Member Plus
  • *****
  • Posts: 5452
  • Country: ca
    • Wind Turbine Project Field Notes
Re: Have I created a monster (of sorts) ?
« Reply #10 on: May 20, 2017, 08:08:40 PM »
Quote
I would have to dig out the 3 coil junction to get to the neutral point. Correct ?

Yes, if you were so inclined.  Which you say you aren't...  No sweat, but it is nice to have options.  Sorry to hear about the lathe.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

oztules

  • Hero Member
  • *****
  • Posts: 1477
  • Country: aq
  • Village idiot
Re: Have I created a monster (of sorts) ?
« Reply #11 on: May 20, 2017, 09:08:16 PM »
Generally here, three phase motors have 6 terminals in the connection box. They go to the three phases separately.

Then they have three brass connectors in there with two eyes, that allow you to use the motor as delta or star (/Wye).

If the three brass bars are in parallel, you have wired it in delta, but if wired as a "TEE", then it is star.... no need to dig out the star point, it is created in the connection box.

Here are pics off the net




The coil voltage is 240v in the above, but will run at 415v here ( they say 440v ) or so if wired in star.

So the phase voltage ( incoming power from phase to phase) is 415v, and the coil is designed for 240v, and thats all it sees in star 415v, but would see 415v across it's 240v coil if connected in delta in this case... bye bye motor in that case.

.....oztules
« Last Edit: May 20, 2017, 09:14:08 PM by oztules »
Flinders Island Australia