Cncst4060

[JAZZCNC]

Did you set the VFD parameters to match your spindle ie: Voltage, current, freq, etc. If not this could be your problem as the defaults may not match your spindle.
I don't know this VFD and don't have a manual to see the fault codes but the usual suspects for fault codes on startup or slowdown is too fast Acceleration or deacceleration settings.

If you have them set to accelerate too quickly and you call for a high RPM then the VFD try's to get to speed in the set time by dumping high amounts of current into the spindle and this trips a Fault because it pushes higher than the set parameter. Likewise if you haven't setup the VFD parameters and it's on the default which is often set low the same will happen.