# Help with my AC motor



## kennybobby (Aug 10, 2012)

My thoughts are that you are not very bright--why would you hammer on the shaft of a motor and damage the internal bearings? You obviously have no clue about the inside of a motor to think that you could just hammer the shaft out one end...

The fan would be removed using a bearing puller tool.

i doubt that you could re-wind the motor given your mechanical knowledge and skills, probably better send it to someone who knows how since you will now need new bearings also.


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## dcb (Dec 5, 2009)

you might as well keep going IMHO and get a look inside one.


the shaft has a key on it, you can gently tap/pry it out with a screwdriver.

You appear to have 4 long bolts that pull the end housings together (allen screws?) those need to come out before the ends will come off. And even then you might need to use heat and a puller to get the bearings off the shaft and/or housing.

Pully and maybe heat for the fan, watch some youtubes, practice on a small motor next time.


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## Quezacotl (Sep 23, 2014)

The motor bearings are so that they wont get harmed when i hammer the shaft. At most the bearings pop out. They are not so tight i would have to heat them out.

Thanks for the tip about the bearing puller. I need sometimes a little nudge to remember some things.

Why you depress people on the first post? That i shoult just quit everything?


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## dcb (Dec 5, 2009)

Quezacotl said:


> Why you depress people on the first post? That i shoult just quit everything?


Lol, he isn't in charge of your feelings. Don't worry about your parents finished wooden floor or anything either...


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## Quezacotl (Sep 23, 2014)

dcb said:


> Lol, he isn't in charge of your feelings. Don't worry about your parents finished wooden floor or anything either...


It's my own floor and house 
Maybe depressing was'nt the right word. English is not my native language. I mean that he was like that i don't know nothing and giving impression that i shouldnt even start a thread.

But thanks for the tips. I'll try them tomorrow when i have time.


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## PStechPaul (May 1, 2012)

It would help to show the label for this motor. If you opened the junction box on top you will find flexible wires and a terminal block or wire nuts with which you can probably wire it for 480 or 240/208, basically stator windings in series or parallel. If haven't pulled the bell housings loose you probably haven't seen the actual windings, which will be solid varnish insulated magnet wire, and the "belts" that go through the stator slots will most likely be stabilized with an additional coating of varnish and/or insulating sleeves and lacing cord. If you can find where the windings connect to the flexible leads you may also find a place where the windings are all tied together for a "star" or "wye" configuration. You may be able to rewire it for a "delta" configuration which will lower the rated voltage by sqrt(3) or about 1/1.7, so instead of 240V it will run on 138 VAC line-to-line.


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## Quezacotl (Sep 23, 2014)

here's the label on the picture.
And the junction box has 6 wires going from the motor.

Yep, i was'nt looking for rewinding it, just rewiring, so i can make it lower voltage through paralleling. To maybe around 100V


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## dcb (Dec 5, 2009)

Just fyi, that probably isn't enough motor for a vw golf. This one isn't gonna win any races but should be sufficient if you keep the transmission or avoid steep hills or limit top speed (weighs 10 lbs less, 156 volt operation, twice the continuous rating, 35kw peak, $300). 
http://www.ebay.com/itm/AZURE-DYNAM...her_Vehicle_Parts&hash=item27cd703867&vxp=mtr

Still would like to get a peek inside the ABB though to see if it is reconfigurable, more knowledge is good, so I hope you will photo/doc/video your trials.

Hit the key with some penetrating oil (wd40 or ???) and let it sit a spell. Then try to remove it with a brass drift.


edit, here is an ac24ls in a golf (at 310 volts, Y assumed which has a chunk more power than 156v in delta), to give you an idea what the motor can do, check out the specs. With that configuration he can do continuous 20kw and max 45kw. top speed 84mph, 0-60 in 15 seconds using the 1st three gears.
http://www.evalbum.com/2315
You are at 7.5kw continuous fyi, so *maybe* 17kw peak in that ABB, it is going to be a long time before you see 60mph, and you might not be able to stay there with all the aerodynamic drag.


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## Quezacotl (Sep 23, 2014)

Just when i posted my last comment, i thought that i'll just saw the key little and pry it out with a screwdriver. That worked like a charm!

The bearings are unharmed, just like i thought. The end plates are not tightly around the bearings. There is only a rubber ring between the bearing and end plate.

Next i'm going to look at the wires, how they are in there, and then ask more questions 


And yea, i know the motor might be too small for my car. But hey, this is mostly an experiment and hobby


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## dcb (Dec 5, 2009)

Awesome!  You can see all that varnish and lacing is a little intimidating (but necessary to keep the wires from vibrating with the magnetic pulses), hopefully somebody chimes in as to if this looks like series and annotates it a bit, if you don't sort it out in the meantime. I would guess start by looking at how many wires are connected to one insulated lead in the case. 

It is looking rather delta-ish in the box, so not sure there is anything else that can be done without digging through the varnish, I'm just a rookie on this stuff though.

Edit: you are gonna need some bigger leads if you start paralleling windings 
Might want to look at some rewinding vids and consider using larger wire in the rotor, or just live with a booger job.
https://www.youtube.com/watch?v=HBF8Ped5Ils
https://www.youtube.com/watch?v=NrsoCKzkQaw


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## Quezacotl (Sep 23, 2014)

Now i got time again, and got to look it again.

I got all the lacing off, but the varnish is very strong. I thought that heat would help, but no. I would need to put that much heat that the enameling from the wires would melt away too.

Now all i can think of is that i'll just pull the wires separate one by one. Or is there a better way?

Next job would be identifying the circuit once i get all separated.

EDIT: I can't pull the wires separate. The enameling peels off from the wires next to what i'm pulling.
The enameling is so fragile that it almost peels off while i'm looking at it.


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## Quezacotl (Sep 23, 2014)

Unless there is better way to lower this motor's voltage, i'll just return it and look for better.

So, what are my options with reconnecting? So far i have'nt found any documents about those 6 wires on junction box. Picture attached.

I measured them, they are connected like this(without those bars you see on the picture):
blue - brown
yellow - black 
green - red


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## PStechPaul (May 1, 2012)

It seems that there are just three windings, and they are connected in delta, so you can't lower the voltage by reconnecting. You could connect them in "wye" or "star", but that would increase the voltage. If you have tried to separate the wires and the insulation has peeled off, it may be damaged to the point that it needs to be rewound. Rewinding costs about $500 at a motor shop. You can do it yourself but it's tricky. I have rewound a couple of small (FHP) motors, that were originally 120V 2 or 4 pole single phase, to 8VAC 8 or 12 pole three phase, and they worked, but probably not very well. However, I was able to run it at 240 Hz and ~2000 RPM, and it should have been capable of 4 times its rated power, but it didn't seem to have much torque.

If you will need to rewind it anyway, your best bet may be to find a larger three phase motor, that perhaps has a bad winding, which you can get for cheap. A motor shop probably has a few in their scrap pile or could find one for you to be rewound.


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## Quezacotl (Sep 23, 2014)

The rewinding sounds tempting, i need to learn more about motor wiring before i do that. And i would need to practice first with some one-phase motors, so i can test it, because i don't have access to three-phase electricity.
But that goes to somewhere in future. I rather have that car running in next half year or i get it trashed.


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## PStechPaul (May 1, 2012)

You can get a small (2-5 HP) 208/240V VFD for about $100 and you can connect it to a single phase AC source or a battery pack of 240-350 VDC. It should be capable of running a larger motor under low load conditions. You can also connect a motor run capacitor from one leg to the third phase and get the motor to run, but at much reduced power. OK for testing, though. If you do rewind a motor, make sure you use an insulation tester or hipot to make sure there are no shorts or damaged insulation.

Good luck!


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## Ivansgarage (Sep 3, 2011)

Quezacotl said:


> The rewinding sounds tempting, i need to learn more about motor wiring before i do that. And i would need to practice first with some one-phase motors, so i can test it, because i don't have access to three-phase electricity.
> But that goes to somewhere in future. I rather have that car running in next half year or i get it trashed.


Rewinding is not that hard if you break it down to one phase at a time. 

Ivan


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## Quezacotl (Sep 23, 2014)

Ivansgarage said:


> Rewinding is not that hard if you break it down to one phase at a time.
> 
> Ivan


Actually, after lookinng at you site and reading about rewinding, it does'nt seem so hard as it looks. I might try it with this motor, if here people are willing to help on calculations.

Only concern is now where to get the required copper for cheap...


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## Ivansgarage (Sep 3, 2011)

Quezacotl said:


> Actually, after lookinng at you site and reading about rewinding, it does'nt seem so hard as it looks. I might try it with this motor, if here people are willing to help on calculations.
> 
> Only concern is now where to get the required copper for cheap...


this is what you should be looking for in wire
http://www.temcoindustrialpower.com/products/Magnet_Wire/MW0154.html

ivan


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## Quezacotl (Sep 23, 2014)

So, my estimation for the total length of the needed wire is about 900 meters(3000 feet). Does that sound correct?

About 70 wires in one slot. (hard to count without pulling them out)
36 slots.
about 150mm slot lenght, and outside the slots is needed about 200mm more wire(total).
total 882m.

And what you would suggest what voltage i should target? Planning using jhuebner's controller, and no batteries yet. I was thinking around 72V(6 batteries in series) or is that too little?

And i have 150A IGBTs. What voltage i should wound the motor so that i could use those? Or should i just push them aside and look for something else.


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## PStechPaul (May 1, 2012)

Depending on the configuration you choose, each slot may have two or more "belts" with different phase currents in each. For the 36 slot rotor, you can get a maximum of 12 poles, which is what I made, and it uses one belt per slot. This would run at a synchronous speed of 600 RPM at 60 Hz, less the slip. For this you want a winding that looks like this, with each belt spanning three slots:

A+ C- B+ A- C+ B- (repeated 6 times for 12 poles and 36 slots)

I was wrong in a previous post about the motor(s) I made. I'll edit that to correct it. I made a 12 pole motor with 36 slots and an 8 pole motor with 24 slots. Here is the 12 pole wound with (I think) #17 wire:


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## Quezacotl (Sep 23, 2014)

New finding!

When i started to unwind the motor, i saw this(look at the picture).

It is wound with 6 coils internally. (correct word poles or inhand or cables?)
All pairs(used to be parallel) have uneven resistance. They are like this:

4,4R
4,0R

4,4R
4,0R

4,4R
4,0R

So what this tells?


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## PStechPaul (May 1, 2012)

You may have a 4 pole motor, which is two pole pairs and three phases, for 6 windings as you show, or if they were in parallel it would be a two pole. One set of belts (windings) may be installed first, so they may be closer to the inside edge of the slots, and the other set may be installed on top of them, which may result in more wire and higher resistance. A dual wound transformer also shows this effect, where one winding is on top of the other and although it has the same number of turns, the diameter is larger and so is the resistance. For critical applications, a transformer (and possibly a motor) can be bifilar wound, where two strands are wound at the same time, but this means that the voltage between strands can be rather high if connected in series. There are also winding patterns such as ABBA (very popular in Sweden) that compensate for the increasing diameter to provide similar resistance and more balanced magnetic coupling.

I am more familiar with transformers than motors, but many principles are the same. Motor winding seems to be somewhat of an art, and some magic may be involved as well. There are many variables such as the ratio of rotor to stator slots and the skew angle and optimum slot fill (sometimes accomplished with square or hexagonal magnet wire for denser packing), and considerations for PWM drive where interwinding capacitance and insulation stress due to high dV/dT need to be taken into account.

Good luck with your winding project. You might consider doing a quick practice rewind using some of the wire you remove from this motor (as long as it is not badly damaged), or you can even use ordinary PVC insulated building wire, and then run the motor using low voltage. I connected two step-down transformers from A-B and B-C on my VFD, to get about 6-12 VAC on the motor, and it worked. It will not be as powerful as a properly wound motor, but you can quickly see if it runs and if you have the poles properly connected. I found that if I reversed a winding in the motor, it ran at half the speed expected, which (I think) was due to "virtual poles" or "interpoles" that effectively doubled the pole count, although torque was very low and I had to start it by spinning the shaft.

Have fun and be safe!


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## major (Apr 4, 2008)

PStechPaul said:


> You may have a 4 pole motor, ....


The name label in post #8 would confirm it is indeed a 4 pole motor.


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## PStechPaul (May 1, 2012)

I thought it was 4 pole, but having just three windings with two wires in parallel made me think it might be 2 pole. Actually, though, 3 phase motors are probably always wound with three continuous windings, and the belts are arranged to span the number of slots corresponding to the pole count. And except for the case of maximum possible pole count for a given number of slots (12 for a 36 slot stator), there are also various numbers of turns in slots where the poles overlap considerably.

It may be possible to get more poles than slots/3, but I doubt it.


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## Quezacotl (Sep 23, 2014)

So, to ensure i understand all, let's clear the terms out:
coil = one long wire of one phase?
belt = same as previous?
pole = same as previous?
turn = one wire in one slot?
inhand = ?

And after thinking a while of the ohm's law, of course there's no advantage of that there exists 12 leads for getting the voltage lower. I'll continue to unwind it 

Any way to soften the varnish so the wires are easier to get out? I don't mean the enamelation on the wires. I mean the varnish on top of everything.


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## dcb (Dec 5, 2009)

it sounds like there are 12 coils in series w/two wires per coil per leg. So there are 12 spots per leg where the leads exit a slot, and skip a few slots and go into another slot. I *think* there should be a way to parallel those, if you can get to them.


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