I fried my spindle motor, and would like to understand why

[dazp1976]

Hi!

Up until an hour ago, I had an Isel ISA 750 spindle. I tried to run this using an Omron JX (3G3JX-AB002-EF) VFD.

I mostly followed the "test run" instructions from the Omron JX inverter handbook:

• Configured the spindle power to 0.75 kW
• Configured the output current to 220V
• Configured number of poles of the motor to 2

In addition, I also configured the frequency settings, but here I was unsure, because the spindle doesn't specify them in the same way as they need to be entered in the VFD. It only lists the "cut-off frequency", which the specs explain as "frequency to which the motor effect is designed". So I thought I would be safe by staying close to those values and made the following settings in the VFD:

• "Base frequency" I set to 295 Hz
• "maximum frequency" I set to 305 Hz

And then I tried to run it. The spindle went up in smoke after approx. 3 seconds, and now has a short between phases.

Now before I try to buy a new spindle and try again, I would like to understand what I did wrong.

Any hints?

I suspect nothing and the spindle was faulty. However I think the max Freq should be set to 400 Hz if you want 24000 rpm ie 60x400 and the base to whatever the min speed is.

The motor states 300hz max.
This kind of thing happens when you mix and match.
Should have got a matching vfd from isel.

May have broke both.