New sentence clarifies how to ensure direct metal-to-metal contact between the metal mounting yoke of a receptacle and the metal box when a bonding jumper isn’t installed to the receptacle.(A) Surface-Mounted Box. Where the box is mounted on the surface, direct metal-to-metal contact between the device yoke and the box is permitted to serve as the effective ground-fault current path. To ensure an effective ground-fault current path between the metal box and yoke, at least one of the insulating retaining washers must be removed from the receptacle.
