Code question; replacing grounded receptacles

[dave*99]

Looking for code requirements for the following job. Replacing grounded receptacles. Currently the house has grounded receptacles. Boxes are steel. The grounding conductor is attached to the side wall of the boxes with a grounding clip. The receptacles are grounded through the yoke vai the 2 yoke screws.
Question: When replacing these (using new TR receptacles) is there any code requirement to connect the ground terminal on the receptacle yoke? Or can I continue to use the yoke screwed to grounded box as the sole ground. I'm looking for the NEC code answer to this.

The house was built in the 60's and I don't think the boxes are tapped for a grounding screw, so adding a ground pigtail may not be simple.

Dave

 

[kkenney]

Dave, Hope this helps

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 onthe 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 thecover 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.
(B) Contact Devices or Yokes. Contact devices or yokes designed
and listed as self-grounding shall be permitted in conjunction
with the supporting screws to establish the grounding
circuit between the device yoke and flush-type boxes.

 

[kkenney]

Just make sure that you have the receptacles are auto ground or self grounding

 

[dave*99]

Thanks guys. I'm using Leviton Decora. Looking at some catalog info, the receptacles with self grounding clips are readily available in residential grade. Switches, OTOH don't seem to be common with self grounding. I may have to pigtail grounds on the switches.
Or are the code rules different for switches??

 

[kkenney]

Dave,
No need for self grounding switches and no need to ground when attached to metal box. see below
(B) Grounding. Snap switches, including dimmer and similar
control switches, shall be connected to an equipment
grounding conductor and shall provide a means to connect
metal faceplates to the equipment grounding conductor,
whether or not a metal faceplate is installed. Snap switches
shall be considered to be part of an effective ground-fault
current path if either of the following conditions is met:
(1) The switch is mounted with metal screws to a metal box
or metal cover that is connected to an equipment grounding
conductor or to a nonmetallic box with integral means
for connecting to an equipment grounding conductor.
(2) An equipment grounding conductor or equipment bonding
jumper is connected to an equipment grounding termination
of the snap switch.

 

[dave*99]

Thanks, looks like I'm good to go.

 

[where2]

Alternatively, you could get an inspector like the one I got who wanted a green ground screw in the box and attached with a wire to all my new TR decora outlets. I just hit the boxes with a cordless drill and an appropriate tap. It took less than 3 minutes a box to give myself a threaded ground screw hole in every box. The screws were a normal US thread size. Simple upgrade. I expected the old screw method my outlets originally had was good enough. Apparently it is, unless you have a fire and the insurance company is looking for something to blame. At that point, everything better be at or above code like my interconnected smoke alarms...

 

[dave*99]

Interesting, I always thought modifications to a box such as drilling and tapping were a code violation. But I'm certainly no code expert.

 

[where2]

The inspector didn't ask to see a certificate of origin on the boxes. They were USA made heavy gauge galvanized steel, circa 1962. He simply told me if I'd used a plastic box my wiring would have passed, but since it was a metal box the box needed to be attached to the ground lead in case there was a defect in the insulation. I can assure the NFPA that I left more steel in the box than I removed with my drill bit! I also vacuumed out the shavings.