I am getting ready to wire up a Huanyang 1.5KW 110V spindle motor and wonder what to do with the ground pin. The motor uses 3 wires, but it has a 4 pin connector. The limited motor documentation says that pin 4 is "earth wire". However, it appears to be completely isolated from the case and the other 3 wires.
I ordered some 3 wire 16ga shielded cable that is a bit too large to fit through the connector that came with the motor. It is a perfect diameter if I remove the outer jacket and clamp around the braided shield. This would ground the spindle sleeve and it would end up grounding my entire aluminum CNC router.
Should I leave pin 4 floating and ground the spindle at the connector? Or should I find a way to just ground what appears to be a floating pin 4 on the motor?
thanks
Steve