Should a ground wire be run back to the neutral bar in a main panel or to the ground bar in a subpanel for a 220V receptacle circuit when using metal conduit or bx and all metal boxes or should the ground pin on the receptacles just be tied to the metal box. If it's just tied to the box, what size wire is required for various amperages?
If one is using common bx with black/red/white wires, should one put the white on the ground pin and tape it green at the recept. and the panel? Is the ground pin suppossed to be tied to the box whether you run the ground wire back to the panel or not?
Would the awnser be the same for New York City as for most other places?