Troubleshooting a perske router spindle 1

[aPojk]

Hi All,

I have a perske router spindle:
vs60.11.2
5.5hp
220v 13.3A
17550rpm 300Hz

I had a current overload error on the VFD, so i took the motor apart and cleaned it out,
ran an insulation test on winding to ground and winding to winding also measured the
resistance on the windings to see if they were consistent. Every measurement i took checked out fine so i got new bearings and assembled the motor.
The same overload error occurred. running the motor at 6Hz, it ran but drew a current of 14A.
ran insulation test again with no faults, had the dc test voltage at 1000v. any pointers on how to proceed with this motor?

Thanks,
Frank

 

[ScottyUK]

Prior to the problem developing, what had been done to the motor?

If the motor measures good, then the drive may be at fault. It's an unusual drive (commonplace, but still 'different' to the majority) and without some reasonable test gear you'll probably struggle to make much progress.

Do you have a standard VFD of, say, a couple of kW available for testing purposes? You could run the spindle motor at reduced speed and frequency from a commodity drive and would perhaps isolate the problem to either the drive or the motor. You will need to adjust some of the test drive to some non-standard settings to match the high speed motor.

 

[itsmoked]

I think Scotty makes good sense.

I find with machine tools it's just about %50 of the time the VFD and %50 the motor. So it's very possibly the VFD.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[aPojk]

i got the complete router quite cheap(or so i thought) since the control system was outdated. I installed a new control system and thought i was done. That was when i saw the VFD was broken. I bought a new VFD from our usual supplier of such things, an Omron JX 5.5Kw. So now it looks like the motor is having some issues too, but i can't seem to let the motor go as long as i can't measure anything wrong with it.
The rotor's not in mint condition, but i've never seen rotors causing behaviour like this.

 

[ScottyUK]

What is the base frequency your new inverter is set to, i.e. at what frequency will it reach full output voltage?

In their default state most drives - other than exotic stuff like dedicated spindle drives - will reach full output volts at either 50Hz or 60Hz depending on where you are in the world. Your motor is expecting full volts at 300Hz. If this config error exists then the net effect would be that the motor is getting either 5x or 6x the voltage it is designed at those low frequencies, which would explain the overcurrent.

 

[LionelHutz]

I agree with Scotty, saw the problem as soon as I saw that 17550rpm, 300Hz data. Set the base frequency or motor rated frequency to 300Hz. Make sure the motor rated voltage is set to 220V at the same time.

 

[aPojk]

Thanks!

Most all motors i deal with are 50hz 220v, so the base frequency didn't cross my mind(though admittedly it should have after the initial problems), with the new inverter(correctly set up) and bearings this motor is now running smooth and silent.

Frank

 

[ScottyUK]

Thanks for the update Frank - pleased your machine is running properly.