Is it acceptable to ground outlets or switches through a metal device box (not pig tailing)?
The switches are connected to a long ground wire going to the light which are also screwed to the back of the box. The Ground form the lead (cut short) is screwed to the back of the box as well. My question is if the metal box is an acceptable method for connecting all the ground wires together completing the chain to the earth. The dark green dots in the diagram are screws fastening the ground wires to the box. (This is in Ontario Canada)
Best Answer
Everyone seems to be answering a question that was not asked by the OP. He is asking if using the bonding screws without also pigtailing the bonding conductors will suffice for bonding.
Yes, the picture you have shown is an appropriate way to bond the devices.
Edit: Additionally, there is no requirement to bond the switches in the CEC with a separate bonding conductor, unless doing so is stated in the manufacturer's instructions. The screws used to mount the switch to the box suffice as the bond.