Spindle dead or vfd dead and how to tell.

[Ollie78]

HI everyone

So, today I was cutting a part from some HDPE plastic and it was going fine, then al of a sudden the spindle slowed down and stopped.

A small bit of information about the setup.
My spindle is not controlled by the motion controller it is just wired seperately and I turn it on or off with a switch and control the speed with the knob on the vfd.

The VFD is an ABB IP20 / UL Open type and the spindle a generic Chinese 2.2kw water cooled unit (cooled by barrel of antifreeze and pond pump).

I have never had any issue with it at all before, tried tech support number one rule and turned everything off and on again, no use.

The VFD makes its normal whiring noise and lights up as normal when it turns on at the socket but when the on switch is clicked no action from the spindle, no obvious loose wires anywhere, it was not hot to the touch so no signs of anything obviously wrong and it was not working hard at the time it died.

So, how can I test if its the VFD or spindle that is at fault ?

And how easy is it to wire in a new spindle? it was already setup when I bought the machine and is about the only bit I haven`t had to mess with.

All advice appreciated.

Ollie

[m_c]

Seems strange that the VFD isn't generating any kind of error message.

First thing would be disconnect the spindle power wires from the VFD, then measure for continuity between them in pairs, and check for continuity between the pairs and earth/gnd.
The three pair combinations should have quite similar values. Any high resistance measurement would indicate a broken wire, or a failed spindle, so you'd need to re-measure directly at the spindle.
And any continuity between those wires and gnd would indicate an insulation failure somewhere. Again, you'd need to re-measure at the spindle.

Failing that, swapping parts out is the easiest option.

[Ollie78]

Hi m_c

Thanks for replying to my question, I managed to spare half an hour today to investigate a little bit.
I have done a few continuity tests, I was surprised to find only 3 pins in the top connector of the spindle, I am assuming the earth is via the shielding ?

So the wires at the VFD are the earth which is to a common plate with the input power, U2,V2 and W2 .

With the spindle still connected I tested the terminals with each other, all beeped indicating continuity and showed a reading of 1.6 to 2 ohms on the multimeter.
I then disconnected the wire at the top of the motor and tested continuity between each of the 3 pins in the motor all beeped and showed 1.6 ohms.

Then I tested each section of the plug with its counterpart on the vfd and they all beeped continuity and showed 00.3 to 00.5 ohms.
There did not appear to be any continuity between ground and anything else.

I am not sure what this is indicating really and am none the wiser.

There is no error message on the vfd, the screen comes on as normal and just reads 0, when switched to spindle on nothing changes, still 0.

I am thinking I will need to test the vfd when powered on to see what is happenning but not sure what setting on the multimeter etc.
Be handy if I had a spare of either to eliminate one or the other.

Ollie

[m_c]

Those tests would indicate that the wiring and the spindle appear to be OK.

Might be worth trying a factory reset on the VFD.

[Ollie78]

Those tests would indicate that the wiring and the spindle appear to be OK.

Might be worth trying a factory reset on the VFD.

This is positive news.
I will see if I can find a manual for it online before I next have a chance to look at it.

Thanks

I will report back, fingers crossed !

Ollie

[Ollie78]

Just a final report.

I have fixed this issue, well sort of.

It appears that the vfd forgot its settings somehow. Previously I was using the on off switch on the small sub panel below the main control section and the pot for speed control. Never using the on, off or menu controls on the main panel.
When I downloaded the manual and started going through a setup process I found it wanted to run through the main screen and other buttons. This is now working as it should, probably as it always should have but when I bought it I just did what the previous owner had done.
Interestingly the other switch and pot I was using no longer have any effect.
I think it must have been set up to run externally and now it is running internally ( I forget the correct term ). I still don`t know why it decided to stop working and don`t 100% trust it but it works for now.

Ollie