If the foot pads and the anti-static wrists are connected together, do they need to be connected to the earth?
A: No, only the device to be handled should be unplugged and electrically connected to the ESD ground, as long as the conductive parts (body surface skin, ESD foot pad, equipment case, operating parts, etc.) are equipotential, ESD (bleed discharge charge) It won't happen. The earth is very suitable for the reference voltage. If you confirm that all the conductive parts are connected to the ground, then it is guaranteed that these conductive parts are at the same potential. Once there is a potential difference between the two conductors, the charge will be discharged. Generate ESD.