No but they should be. IMO all receptacles should be required to have the self-grounding clip. I mean how much could it cost the manufacturer to install that on the device like 5 cents?
I meant of the “self grounding receptacles” that are out there.
Yes those are not typical. Harry Homeowner goes to Big Orange and buys the 99 cent receptacles that lack the self-grounding feature.
I honestly couldn’t recall if I knew about these, so I did a little reading on them. Interesting how much mixed info there is out there about them.
So @rmeier2 let’s say these were installed in an older house with a 2 wire system and metal boxes, and the boxes themselves were not grounded, just simply nailed to the studs, and AC cable was NOT used.
-
Would a standard receptacle tester still show an opened ground? Or would it get confused like it does with a bootleg ground?
-
If metal boxes are found in an older home, what is the safest way to test the box to see if it was in fact grounded in a way that was not visible, besides calling a licenced electrician? One could assume checking for continuity with a volt meter would work, or some other type of testing tool, but if that person doesn’t know how to go about it correctly, it could be dangerous, in more ways than one.
Some of the metal boxes I came across during this inspection had a screw in the back of the box. I assume that screw was intended for a grounding conductor or “jumper wire” to the receptacle ground. I would imagine some people would use it in that way when installing new 3 prong receptacles, but if the box itself isn’t truly grounded, then using a jumper wire would seem useless.
- Yes the tester would still show open ground if the metal box had no connection to something that was grounded.
- The safest way to test the box is to first identify the wiring method to see if it does actually contain an EGC. Next you would need to ensure that the EGC is connected properly to the metal box.
So if the metal box is properly grounded by the wiring method (let’s say armored cable) a standard receptacle is not permitted to be grounded by the two mounting screws unless the receptacle is a listed self-grounding type. A standard non-self-grounding receptacle can be used but would require a bonding jumper to the grounded metal box.
One other thing worth noting this requirement only applies to receptacles. Standard wall switches (snap switches) are permitted to be grounded to a metal box by the two 6-32 mounting screws. A self-grounding switch is not required.
2 Likes
One issue is that a box can show as grounded but does not provide a low impedance ground path. A fault can have the sheath glowing red and not trip a breaker.
1 Like