Connector Listed for grounding and direct bury

[electrofelon]

In what cases or situation does a connector or fitting need to be listed or approved for grounding? I seem to remember that been required somewhere but can't remember where.

Also, when does a connector need to be specifically listed or approved for direct bury?

For example, say I have an H-tap approved for CU to CU. Can I use that on a GEC underground?

 

[don_resqcapt19]

110.14(B) requires any splice or wire connector used underground to be listed for that purpose. I would doubt that an H tap is so listed, but not sure.

 

[wwhitney]

The text I excerpted in the following post bears on this question:

New One For Me….

I got this comment stamped on the plans I submitted for a generator install. This is my drawing of the load side feed from the main disco, to the transfer switch, then back into the panel to be split bolted or Polaris connected to the feed to the house. Pretty standard and simple set up. I...

forums.mikeholt.com

You need a connector listed under ZMWQ or if it is a grounding application, KDER. A connector listed only under ZMVV has not be investigated for underground use.

Cheers, Wayne

 

[electrofelon]

Ok so the direct bury part is clear cut. I am still confused on the listed for grounding issue. Let's take the direct bury issue out by staying this GEC splice is not underground. H taps seem "intended" for the connection of grounded and ungrounded conductors. Does that mean that per Wayne 's linked post they are likely NOT listed to KDER and can't be used for EGC's and GEC's?

 

[wwhitney]

Does that mean that per Wayne 's linked post they are likely NOT listed to KDER and can't be used for EGC's and GEC's?

My take is no. KDER-only connectors can only be used for grounding and bonding (and KDER covers a lot of things besides connectors), while ZMVV connectors can be used for anything (within environmental limits).

An open question is whether there exist KDER-only split bolts or like (the possibility I raised in the above referenced thread), or if all such connectors are listed under ZMVV as well. I did look up one particular direct burial split bolt and found it was listed under both KDER and ZMVV, but did not attempt an exhaustive search.

References:

NEC 250.8(A); item (1) I take to mean listed under ZMVV, while item 3 I take to mean listed under KDER.

The UL guide info for KDER and ZMVV (which also mentions ZMVX for underground wire nuts) can be found here with a free UL account:

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Or if you don't want to make an account, you can find an old version of the UL White Book as a PDF that you can download, just search for it.

Cheers, Wayne

 

[electrofelon]

.....ZMVV connectors can be used for anything (within environmental limits).

Ok, at first when read the following part in red:

UL product category Wire Connectors and Soldering Lugs (ZMVV) covers single-polarity wire connectors for use with copper, aluminum or copper-clad aluminum conductors or all three for the purpose of providing contact between current-carrying parts.

I was reading it from an NEC perspective of "current carrying conductor" which made me think it couldn't be used for EGC's and GEC's, but upon further thinking, I doubt that is their intent.

So circling back to the other part of the OP, where I have I heard this "listed for grounding and bonding " phrase?

 

[jim dungar]

So circling back to the other part of the OP, where I have I heard this "listed for grounding and bonding " phrase?

For example:

All wire nuts can be used for any electrical conductor connection, however green wire nut, with the hole on tip, can only be used on grounding conductors.

The are some bronze connectors that can only be used on grounding conductors, they look like split bolts, but can be threaded into a transformer tank.

 

[retirede]

Ok, at first when read the following part in red:

UL product category Wire Connectors and Soldering Lugs (ZMVV) covers single-polarity wire connectors for use with copper, aluminum or copper-clad aluminum conductors or all three for the purpose of providing contact between current-carrying parts.

I was reading it from an NEC perspective of "current carrying conductor" which made me think it couldn't be used for EGC's and GEC's, but upon further thinking, I doubt that is their intent.

So circling back to the other part of the OP, where I have I heard this "listed for grounding and bonding " phrase?

An EGC will carry fault current when necessary. Surely that counts?

 

[Greentagger]

The “ listed for bonding and grounding “ portion of your question is referenced in 250.64(C)(1).

 

[Fred B]

To be clear, you are referring to an EGC and not a GEC?
For the most part any connector suitable for any other conductor in similar conditions are usable for an EGC, other than the EGC tapping wire nut green with hole in top mentioned by Jim, (only usable for grounding conductor). If you have to splice different wire types Al/CU, Is splice product listed to be able to connect the 2 together.
Don't see an issue with an H-tap for either the EGC or a GEC as H-tap would be considered "non-reversible", (needed for a GEC splice). H-tap, if rated Al/Cu, Cu wire not in contact with the Al wire directly on an H-tap anyway.
Any connector to be used underground would need to be listed for "direct bury" DB.

 

[electrofelon]

To be clear, you are referring to an EGC and not a GEC?
.

Both I guess.