Need re-winding data for Chinese 10 kW ST head please

[rcavictim]

Have any of you ever run across any instructions as to rewinding a burnt out Chinese ST head like an ST-10? In my search of so called 'industry experts' at Ontario motor rewinding shops I have come to the conclusion that, not unlike most other service industries today, these 'experts' know absolutely shit unless they have instructions in front of them on a computer screen.  They wouldn't have the inclination, or likely the know-how, to install a few known turns in a stripped out core, spin it up and do voltage measurements achieved in order to determine the volts-per-turn of a particular unknown core if it was required to save their sorry ass.  I figure I will likely have to do this myself but GEEZE, there HAS TO BE someone out there who has this info already!

I'm planning to dispense entirely with the harmonic exciter winding and obtain the power for the spinning field (which is still good on my machine) from one of the output windings through a step down xfmer and bridge rectifier.  Experience shows this to give superior output waveforms.  If you pass the output AC through a winding on this xfmer it can act as a boost-buck and provide output regulation as well.  Getting that xfmer configured correctly will take a bit of trial and error.

Thank you for any help.

[mbryner]

Well, have you tried any of the hydroelectric guys.   Locally I would go to APM Hydro because Jerry O. there designs and builds his own generators, turbines, etc.   Of course you're on the other side of the country, but some the local hydro guys there might help.    Just an idea...

Marcus

[Thob]

Is it really so badly burned that they can't measure the wire diameter, figure out what size it is, count the turns as it's unwound and then re-wind it back like it was?  Or is that too difficult?  If there's four poles, there should be four identical windings, you really only have to count one of them!

[TimSR2]

DIY it.

Probably only one coil is in need of repair or replacement.    I have successfully rewound coils for generators in past...  and even rewound transformers  to new values.   Just mike the wire to get the right gage, count the number of turns as you unwind it, and rewind it exactly as it was before.  Check youtube for tips.  Once you find the store that sells the magnet wire in your city they will also have the high temp tape and lacquer and advice you need for the job.  You can easily make your own coil winders.  If a backwoods shop in China or India can do it.......

[playdiesel]

I figure I will likely have to do this myself

I know that you will have to do this yourself!

I say that knowing what we just paid to have some rewinding work done here at work.  Id bet that rewinding and ST10 woud cost 2X of what you can buy  a new one for.

Is an interesting sounding project. I assume you will keep us posted on the progress.

[mobile_bob]

befriend the local rewind shop owner/foreman or clean up boy

once having done so, ask who the old dude is that rewinds motors/generators
there is usually one old guy hanging around that is older than dirt and gets all the odd projects.

once he is found, tell him what you want to do
tell him that the unit is wound for some odd 50hz voltage and you want to rewind it for 60hz operation or visa versa
and tell him you are on a limited budget monetarily but have lots of time on your hands.

generally with some diplomacy/donuts/beer he will tell you what you need to know, most of which has been mentioned
however he will also be able to supply you with not only the needed wire, but the slot liners (once known as "fish paper")
and the top strips (the hard fiber strips that keep the winding down in the slot) all of which comes in various sizes. you will need
to know what size wire you have, how wide the top of the slot is, how high a voltage you are winding for, so that he can provide
all the necessary stuff.

he can also provide you with a dip and bake one you get the thing done.

often times they will give you everything but the wire, dip and bake. things like info, slot paper and top strips are priceless and very difficult
to source anywhere but a motor rewind shop.

bob g

[rcavictim]

befriend the local rewind shop owner/foreman or clean up boy

once having done so, ask who the old dude is that rewinds motors/generators
there is usually one old guy hanging around that is older than dirt and gets all the odd projects.

once he is found, tell him what you want to do
tell him that the unit is wound for some odd 50hz voltage and you want to rewind it for 60hz operation or visa versa
and tell him you are on a limited budget monetarily but have lots of time on your hands.

generally with some diplomacy/donuts/beer he will tell you what you need to know, most of which has been mentioned
however he will also be able to supply you with not only the needed wire, but the slot liners (once known as "fish paper")
and the top strips (the hard fiber strips that keep the winding down in the slot) all of which comes in various sizes. you will need
to know what size wire you have, how wide the top of the slot is, how high a voltage you are winding for, so that he can provide
all the necessary stuff.

he can also provide you with a dip and bake one you get the thing done.

often times they will give you everything but the wire, dip and bake. things like info, slot paper and top strips are priceless and very difficult
to source anywhere but a motor rewind shop.

bob g

There is a wholesale supplier about 45 minute's drive from  me that carries enameled wire, slot paper, top strips, Glyptol motor varnish, etc. Electrowind Efico, Guelph, ON.  I used to deal with them when building my large commercial tesla coils so obtaining these items is not a problem.

I agree with and was aware of the rest of your suggestion Bob.  Thanx.

[mobile_bob]

i figured a guy like you would have a handle on all the stuff already, but figured others might benefit from
my posting.

once long ago i had trouble getting slot paper from a local rewinder, he was having a bad day i guess...
he sent me to a wholesale dealer which  told me he could supply the paper but i would have to buy a box of it
something like 500 sheets of 24x30 inch which would have lasted me several lifetimes.

he finally took mercy on me, opened a box and snagged out two sheets and gave it to me free of charge.

i guess two sheets out of 500 no one cares about at the wholesale level.

bob g

[tinkerer]

Hello! Just curious as to how your rewinding experience turned out.

[rcavictim]

Hello! Just curious as to how your rewinding experience turned out.

Haven't got a round tuit yet.  Too much other crap landed on my plate this winter and I'm still dealing with it.  The past three months have been absolute hell.

[tinkerer]

Sorry to hear about that. Hope things begin to go better for you.

[akatosborne]

Hi,
See where you may need have a bad excitation winding in your ST.
Have not been on the forum in a while but i have some ideas as to how to eliminate the Z winding by using an 115 Volt AVR
We have been able to repair quite a few of the ST that the excitation winding has opened.
If your interested, let me know
Thanks
Tom
akatosborne@hotmail.com

[rcavictim]

Hi,
See where you may need have a bad excitation winding in your ST.
Have not been on the forum in a while but i have some ideas as to how to eliminate the Z winding by using an 115 Volt AVR
We have been able to repair quite a few of the ST that the excitation winding has opened.
If your interested, let me know
Thanks
Tom
akatosborne@hotmail.com

Tom,

Mine is beyond excitation winding removal.  I've stripped the stator clean and ready for a total rewind.  I was not going to bother with an excitation winding and as you suggested planned to excite the unit from a custom made AVR from the actual output windings.

I still haven't had a chance to look at this and it looks like I never will.  Something much more important was just dropped into my lap.

The rotating field armature is perfect.  If anyone wants to make me an offer on this I'll entertain it.  I need to recover my cost.

Rob

[Frank S]

I guess in some respects having a job in a developing country has its advantages.where I'mat I can count over 30 motor/ gen/ transformer rewind shops with in a 3 block radius. when I first came over here I had a small motor that was wired for 120v only no  possible way to simply change a few lugs and get 240v I ran it on a transformer for a while but that was a hassle one day one of the labors hooked it direct in a few minutes it let the magic smoke escape. I thought about doing the rewire myself just cut the loop ends  off of the coils punch out the wires and count them as they fell but I wanted to change the voltage and go from 60 hz to50 hz but retain the original 60 hz rpm not what it had been running on with the 50hz. So off to find a guy with hair in the change of color like mine was doing.
Finding a guy was easier than I could have imagined . I carried it in to him and tried to explain what i wanted he handed the motor to his labor to open it up Now there was no data label on this old motor the guy took 1 look at the coils all nicely blackened and half melted.
Then said motor not good bad voltage I fix no problem,What speed you need?
I wrote down the number and he said AH,ha you need 60 cy speed on 50 cy no problem I make better than new you see, come back 3 hours cost you $20,00 US I make number 1 power , you see.
when I picked it up ha had it looking like it had just been taken out of a box hooked up and running with a RPM meter  volt and an amp meter then took a piece of hard wood and forced it against the pulley we watched the meters for  minute.
You touch not hot better than new YES?
I agreed and he handed me the bill.
$15.00 US only you my Amerikie Friend you bring all for me YES? I handed him the 20 and said you keep the change I will send you all my business. in the 9 years I've been here I have sent him dozens of motors never had a bad one after he worked on them. He sadly passed on last year from copper poisoning

[Geno]

WOW, what else to say.

Thanks, Geno