I haven’t been able to find a clear answer on this issue. Is a jumper needed from the receptacle ground screw to the metal box if the conduit is being used as the ground path?
NO. The receptacle is affixed to the box with a metal screw through the frame of the receptacle. They are bonded by attachment hardware. There is no bond when the cover is detached as pictured.
With that type of cover (dimpled corners) a bonding jumper from the receptacle to the box is not required. The receptacle is required to be connected to the cover by a minimum of 2 screws.
Thank you to both Roberts above! Google was telling me everything from jumper not required if plastic washers have been removed and receptacles must be rated for self-grounding, to must have a dedicated ground wire and conduit path not allowed.
Nice to get a plain answer here on the board!
Not when the GRC, RMC is bonded.
The conduit is not relevant.
What’s required is that the outlet be “self grounding” or use a jumper.
Metal boxes are always grounded, either via conduit, or via the bare wire ground from the wire. In the past MC cable was considered a ground as well. Metal covers are considered connected to their box (and thus grounded) when they have two or more screws.
The installation photographed looks fine.
A ground wire would be fully optional.
A self-grounding receptacle is not required for this installation where there is a grounded metal box and a listed exposed work cover with dimpled corners. The EMT is permitted as the equipment grounding conductor for the box, cover, and receptacle. Here’s the relevant NEC code section. The part in bold pertains to Ryan’s photo. Also the removal of one of the insulating washers that Ryan mentioned in post #3 does not apply to the box in the photo.
250.146 Connecting Receptacle Grounding Terminal to Box.
An equipment bonding jumper shall be used to connect the grounding terminal of a grounding-type receptacle to a grounded box unless grounded as in 250.146(A) through (D). The equipment bonding jumper shall be sized in accordance with Table 250.122 based on the rating of the overcurrent device
protecting the circuit conductors.
(A) Surface-Mounted Box. Where the box is mounted on the surface, direct metal-to-metal contact between the device yoke and the box or a contact yoke or device that complies with 250.146(B) shall be permitted to ground the receptacle to the box. At least one of the insulating washers shall be removed
from receptacles that do not have a contact yoke or device that complies with 250.146(B) to ensure direct metal-to-metal contact. This provision shall not apply to cover-mounted receptacles unless the box and cover combination are listed as providing satisfactory ground continuity between the box and the receptacle. A listed exposed work cover shall be permitted to be the grounding and bonding means when (1) the device is attached to the cover with at least two fasteners that are permanent (such as a rivet) or have a thread locking or screw or nut locking means and (2) when the cover mounting holes are located on a flat non-raised portion of the cover.