Hello all,
Ive been running my vfd and spindle without fault for the last year and about 1 month ago I added an earth to the spindle as it it only the 3 pin connector and not the 4 pin. All was working well and the last time I used it all was well and shut it down. Tried to run it yesterday and the spindle just will not start up. The VFD seems to do its normal thing as the hertz numbers increase on the lcd but I am getting no resistance on the motor at all. I can still free spin it as tho nothing is powering it. I have checked all fuses and they all seem fine. Ive changed the vfd back to panel control and it still does the same thing.
Ive checked resistance between each pin on the spindle and they are reading about 1.6 each. Ive checked all connections with cabling etc. Ive even tried a second spindle and still the same. I am at a loss about what is wrong with it. I am considering buying a new vfd and spindle just to start again but would rather just buy a bosch or hitachi vfd if I know my spindle is fine and its the vfd.
Is there anything else I can check?

please help

a bit about the machine
2.2kw water cooled chinese spindle
huangyang vfd
gecko g540 controller
mach3 software

Thanks
Merlin