[RCaffin]

A couple of thoughts or suggestions.
I thought that the VFD was not reporting a short circuit in the windings, rather a leak to earth? (But I might be wrong.) If so ...

* Get a motor rewind shop to put the winding on a growler to see whether there is a shorted turn. Failing that, measure the windings with an L/Q meter. If the Q is not terrible, the windings may be intact with no internal shorts. This would be wonderful. If there is an internal short ... full rewind needed.

* Go over the outer surface of the windings with a magnifier. Look for any charring or exposed copper. Alternately, put the winding back in the housing and hang a high voltage between the housing and a winding - to see if there are any current leaks at high voltage.

My first guess, IF the VFD reports a problem as you ramp up the volts, is that there is a partial leak from winding to case. This can be fixed! But I may be mixing this motor up with another one in a similar state.

Wrap the rotor with layers of foil or something so it is a tight fit inside the windings. Insert into windings. Find where the leakage is happening, clean it and gently tap the winding down there - 0.1 mm is enough. Coat the surface with a PU or silicone coating or even varnish in that area and really smooth the coating down. Remove wrap around rotor so it can spin freely. Replace winding in case and try again.

If this works - replace bearings.

Cheers
Roger

[kafie1980]

Roger,

Thanks for the tips, although I havent seen a growler in a shop for more than 20 years or so. I used to see them in shops repairing car alternators and starter motors. But not anymore as everyone seems to just use multimeters..

Let me see if they have a growler in the shop where I gave the motor for rewinding (if they can do it) and see how the windings behave. Although I doubt they will want to spend so much time on doing small repairs versus a full rewind job.

As for physical inspection of the windings, I will probably do that once I pull the core out of the spindle frame.

Thanks again for the advice.

[mactec54]

Roger,

Thanks for the tips, although I havent seen a growler in a shop for more than 20 years or so. I used to see them in shops repairing car alternators and starter motors. But not anymore as everyone seems to just use multimeter...

You are correct a hand held growler to check the stator windings, for this small motor would be hard to find anywhere

A simple check with an OHM meter will tell you more, as to the condition of the stator

Broken coil (infinite coil resistance)

Short-circuited coil (less than normal or zero coil resistance)

Leaking coil to Ground (current leaking from one coil to Ground)

Two or more coils short-circuited with each other (current leaking from one coil to another coil)

[kafie1980]

I got my motor back yesterday as the rewinding shops cant work with such small diameter.

I pulled the core out of the spindle today, tried a bit of heat at home but heating didnt help as the press fit was very tight, so ended up using a hydraulic press with some approximately 50mm steel tubing to pull it out of the spindle frame.

I was in a rush as I didnt want to bother the machine shop folks with me being around as they let me use their hydraulic press for free. well it only took 10 seconds on the press.

next few days I will revisit the rewinding shops to see if they are comfortable working with the stator coil out of the spindle frame.

[KH0UJ]

If you can find Electrical Supply there in malaysia that sells hermetic magnet wires buy at least 150 grams, I think it`s the best material for the job you dont need to ship it here because I assume malaysians are quite as good as the filipinos, were almost the same, slightly different culture but almost the same race all I can say is it`s harder to rewind a conventional electrical fan with coil speeds of low , medium and high @ 60HZ than rewinding that variable frequency 3 phase motor.

[propellanttech]

I'm wondering if I could just gut mine and put hybrid ceramic bearings inside of it. Would be some money, but may be worth it.

James L

[mactec54]

I'm wondering if I could just gut mine and put hybrid ceramic bearings inside of it. Would be some money, but may be worth it.

James L

You sure can, as many have already done, beware not all of the spindles are like this one, most have precision sealed AC Bearings, You also need the correct tools to take it apart or you will turn it into trash

[tonyfoale]

I have just had to strip my identical one for a very similar reason. I had been running my mill with it set to 40 Hz with a max. of 60 Hz and I forgot to set the max. to 400. However, I got to the OFF button within a few seconds of running, when I saw and smelt the smoke. It had got very hot. After letting it cool I set the VFD correctly and ran it up at different speeds and all seemed fine. Anyway I thought that I had better check it out to see if there was any sign of damage to the "German" bearings and the windings.
The bearings seemed like new and the only damage was to the cloth binding on the exposed ends of the windings, from your pix. it looks like you have the same damage. These ends would have been the hottest parts, the part of the windings in the core would have had some cooling. However, under that binding my coils look in good shape. I put it back together after cleaning the rotor, it was only lightly stained from the combustion products, nothing like yours. It is working perfectly.

[mactec54]

I have just had to strip my identical one for a very similar reason. I had been running my mill with it set to 40 Hz with a max. of 60 Hz and I forgot to set the max. to 400. However, I got to the OFF button within a few seconds of running, when I saw and smelt the smoke. It had got very hot. After letting it cool I set the VFD correctly and ran it up at different speeds and all seemed fine. Anyway I thought that I had better check it out to see if there was any sign of damage to the "German" bearings and the windings.
The bearings seemed like new and the only damage was to the cloth binding on the exposed ends of the windings, from your pix. it looks like you have the same damage. These ends would have been the hottest parts, the part of the windings in the core would have had some cooling. However, under that binding my coils look in good shape. I put it back together after cleaning the rotor, it was only lightly stained from the combustion products, nothing like yours. It is working perfectly.

Sounds like you got lucky, how long it lasts will be another story, once the insulation is burned then the wires can easily short with the high frequency

There is at least 4 Parameters that have to be set to 400Hz not just 1 , there is also a minimum that you have to set

[tonyfoale]

Sounds like you got lucky, how long it lasts will be another story, once the insulation is burned then the wires can easily short with the high frequency

The wire insulation shows no sign of damage so I am hopeful. My unit will only see occasional use. Monthly rather than daily.

There is at least 4 Parameters that have to be set to 400Hz not just 1 , there is also a minimum that you have to set

Yes I understand that but for testing it is the max frequency which sets the V/f ratio and that is what caused my problems. Anyway that is done and finished with now.
However, you seem to be the guru here on these VFDs and I have some questions which I hope you can help with.
For 15 years or so I have been using an ABB VFD to drive a mill motor. That VFD is rated at 2.2 kW (the largest 1 to 3 ph VFD that I could find at the time) and originally it drove a 1 hp motor. i changed the motor to 5 hp and occasionally I inadvertently loaded it beyond 2.2 kW and it tripped out as expected. I have very recently got a 4 kW Huanyang device to replace it to run the mill up to 60 Hz and also the 400 Hz spindle that I mentioned. So from time to time I will need to change the settings between the two. The old ABB unit had a macro feature in which I could save various parameter sets. Do you know if this is possible with the Huanyang unit? As others have mentioned the manual is somewhat lacking in explanation, but it shows settings for multiple frequencies without explanation. Are these available for some sort of similar macro feature for rapid change of driven motor? Otherwise it will be tiresome changing numerous parameters each time I change motors.

[mactec54]

The wire insulation shows no sign of damage so I am hopeful. My unit will only see occasional use. Monthly rather than daily.



Yes I understand that but for testing it is the max frequency which sets the V/f ratio and that is what caused my problems. Anyway that is done and finished with now.
However, you seem to be the guru here on these VFDs and I have some questions which I hope you can help with.
For 15 years or so I have been using an ABB VFD to drive a mill motor. That VFD is rated at 2.2 kW (the largest 1 to 3 ph VFD that I could find at the time) and originally it drove a 1 hp motor. i changed the motor to 5 hp and occasionally I inadvertently loaded it beyond 2.2 kW and it tripped out as expected. I have very recently got a 4 kW Huanyang device to replace it to run the mill up to 60 Hz and also the 400 Hz spindle that I mentioned. So from time to time I will need to change the settings between the two. The old ABB unit had a macro feature in which I could save various parameter sets. Do you know if this is possible with the Huanyang unit? As others have mentioned the manual is somewhat lacking in explanation, but it shows settings for multiple frequencies without explanation. Are these available for some sort of similar macro feature for rapid change of driven motor? Otherwise it will be tiresome changing numerous parameters each time I change motors.

So why did you buy a VFD that is not suitable to do both, why did you buy a single Phase ABB VFD in the first place, you don't need a single Phase VFD because you only have single phase power, you can run any 3phase VFD drive with single phase power, up to what ever your power supply can support

So the answer is no the Huanyang does not have a feature where you can have to separate program profiles, only better quality more expensive VFD Drives offer this a snip below is what you would see if the VFD can have more than ( 1 ) motor profile programed

Yes it would be a pain to have to reset the parameters each time, easiest is to get another VFD for your high speed spindle, with your mill motor you could use the VFD up to 100Hz for your motor this will give you more RPM's

[tonyfoale]

So why did you buy a VFD that is not suitable to do both, why did you buy a single Phase ABB VFD in the first place,

Simply because 15 years ago I got it for a single task. In fact i doubt that the 400 Hz spindles were readily available then. Even if they were, I hadn't heard of them and didn't need one anyway.

you don't need a single Phase VFD because you only have single phase power, you can run any 3phase VFD drive with single phase power, up to what ever your power supply can support

Strange that a company like ABB saw fit to make the single phase units at that time.

[mactec54]

Simply because 15 years ago I got it for a single task. In fact i doubt that the 400 Hz spindles were readily available then. Even if they were, I hadn't heard of them and didn't need one anyway.



Strange that a company like ABB saw fit to make the single phase units at that time.

Almost VFD manufactures make single phase VFD, even back 15 years ago, 400 Hz drives was a standard item for most manufactures also, they go well over 1000Hz now

Spindles where available also, but they where not for the Home Hobby machinist, unless they wanted to spend lots of money

No VFD Drive salesman will offer you a 3ph VFD if they have a single phase that will do the job

What's the max Hz of your ABB VFD as if it does 400Hz then you can use that for your high speed Spindle, if you have the ACS 150 model it will run your spindle

[phil c]

Not only is going rock bottom cheap a waste of money. It's a waste of time. If you don't already know what's out there and how the items work you can waste months. I spent three months trying to fix a CNC cutter I built years ago. It literally took 3 months to search through all the newer stuff, figure out if it could work, wasted some money on cheap Chinese stuff, and finally bought a fairly inexpensive US made stepper driver and some surplus motors to get it back to working pretty much the way it was but with more torque. While it still works OK I'm planning on spending some time and materials building a brand new on machine to put the electronics on, since the prices of things like ball screws have come down so much I can build something a hundred times better for the same dollars spent years ago.