Does Self-Grounding Receptacle meet 250.148 (C) requirements

[theRandy]

Hello all, long-time lurker here but first time posting. I need to settle argument between several of my guys, lol!
Scenario is EMT conduit with wire-type EGC run to self-grounding receptacles in 4" square boxes. 250.148 (C) requires connection between 1 or more EGC's and a metal box by means of grounding screw, equipment listed for grounding, or listed grounding device. The question is can the wire-type EGC be terminated only on the self-grounding receptacle and count the receptacle as the listed grounding device to make the connection to the metal box required by 250.148 (C)?
If yes, then would 250.148 (B) apply? The wire type EGC's are connected together with pigtail to device so in case of device being removed the box is still bonded through the EMT but the EMT would no longer be connected to wire-type EGC. I'm thinking if the device is removed the pigtail could just be taken to the box but we're having to rely on future device removing person to know that.
*Note - here in PA we're on 2017 NEC
Thanks and happy electrician-ing!

 

[infinity]

A device cannot be used to bond the metal box. If there is a wire type EGC it must be connected to the box even when the raceway qualifies as an EGC.

Welcome to the Forum.

 

[theRandy]

A device cannot be used to bond the metal box. If there is a wire type EGC it must be connected to the box even when the raceway qualifies as an EGC.

Welcome to the Forum.

Thanks infinity. Our policy is we always pull the wire-type EGC even in metal conduit but my guys are having trouble wrapping their heads around the idea that NEC doesn't require them to pull wire-type but if they do then it has to hit box and device, or just the box, but cannot hit just the device

 

[LarryFine]

The question is can the wire-type EGC be terminated only on the self-grounding receptacle and count the receptacle as the listed grounding device to make the connection to the metal box required by 250.148 (C)?

No, they don't mean a switch or receptacle, but something like a G-clip.

The wire to the receptacle is what's "optional" never the wire to the box.

 

[don_resqcapt19]

I really think this rule is backwards...it should require the EGC to be terminated to the receptacle and permit the receptacle to bond the box, but the code does not permit that.

 

[Eddie702]

I really think this rule is backwards...it should require the EGC to be terminated to the receptacle and permit the receptacle to bond the box, but the code does not permit that.

Agree. To me grounding the receptacle is more important

 

[Krusscher]

Agree. To me grounding the receptacle is more important

Especially if the conduit is already grounding the box, I don't really understand why the redundant wire type egc needs to be attached to something that is already grounded by code.

 

[wwhitney]

A device cannot be used to bond the metal box. If there is a wire type EGC it must be connected to the box even when the raceway qualifies as an EGC.

My understanding as well, but I can't see to find the correct section in Article 250?

Especially if the conduit is already grounding the box, I don't really understand why the redundant wire type egc needs to be attached to something that is already grounded by code.

If you want that green wire to be a redundant wire type EGC, then it would need to follow the rules as if the conduit were plastic. But with a metallic conduit EGC present, I don't see why you couldn't land the green wire directly on the receptacle and just call it a bonus bonding jumper. Assuming the receptacle is of the self-grounding type, so that (2020) 250.146 is satisfied by 250.146(B).

I really think this rule is backwards...it should require the EGC to be terminated to the receptacle and permit the receptacle to bond the box, but the code does not permit that.

But the receptacle is more transient than the box--if the receptacle were removed the box would be unbonded. Similar logic with the neutral conductor of an MWBC, its continuity can't depend on the device. 250.146 covers the various way of providing an EGC connection to the receptacle.

Cheers, Wayne

 

[don_resqcapt19]

My understanding as well, but I can't see to find the correct section in Article 250?


If you want that green wire to be a redundant wire type EGC, then it would need to follow the rules as if the conduit were plastic. But with a metallic conduit EGC present, I don't see why you couldn't land the green wire directly on the receptacle and just call it a bonus bonding jumper. Assuming the receptacle is of the self-grounding type, so that (2020) 250.146 is satisfied by 250.146(B).


But the receptacle is more transient than the box--if the receptacle were removed the box would be unbonded. Similar logic with the neutral conductor of an MWBC, its continuity can't depend on the device. 250.146 covers the various way of providing an EGC connection to the receptacle.

Cheers, Wayne

But, in general the hazard is related to the things connected to the receptacle and not to people who may be touching the enclosure. I will continue to see this as backwards. If you are removing the receptacle for repair or replacement the power should be off. If the receptacle is being removed and not replaced, you can connect the wire type equipment grounding conductor to the box at that time.

 

[wwhitney]

If the receptacle is being removed and not replaced, you can connect the wire type equipment grounding conductor to the box at that time.

The way the NEC is currently written avoids having to remember to do that. If you install a receptacle, you must provide a grounding connection per 250.146.

Cheers, Wayne

 

[hbiss]

Scenario is EMT conduit with wire-type EGC run to self-grounding receptacles in 4" square boxes.

(1) The EGC(s) must ALWAYS connected to a ground screw in the back of the box. This can either be directly or via a grounding pigtail.

(2) You don't say how the receptacle is mounted to the box. If you use a raised plaster ring then nothing else needs to be done given that the receptacle is self grounding.

(3) If you use an "Austin" cover as with a surface installation, even with a self grounding receptacle you must provide a pigtail from the ground screw on the receptacle to the pigtail going to the box ground screw.

-Hal