Myers Hubs

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iggy2

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I give up....

Can someone point me to where Myers hubs are required? Also, what is the generic term for a Myers hub- sealing hub, enclosure hub, etc?

Thanks.
 
Re: Myers Hubs

Is a meyers hub the same as or one of what 250.92(B)(2) refers to.

I think that's the question behind this and the other thread.
 
Re: Myers Hubs

Is a meyers hub the same as or one of what 250.92(B)(2) refers to.
Click to expand...
I don't think so, that paragraph refers to threaded bosses on enclosures, which I think is like the hub on an FS box.

The previous thread posted by Paul refers to 314.15(A). But not exactly what I was looking for.

I recall a code section that required a (Myers) hub on sheet steel enclosures when punched with KOs under certain conditions (wet/exterior location). But I have gone all through the NEC, and can't find what I am looking for. It must have been removed, or maybe I saw it in a previous life....

314.15(A) will have to do.

Thanks, and Merry Christmas
 
Re: Myers Hubs

Originally posted by iggy2:
Is a meyers hub the same as or one of what 250.92(B)(2) refers to.
Click to expand...
I don't think so, that paragraph refers to threaded bosses on enclosures, which I think is like the hub on an FS box.
Click to expand...
Actually, I do believe a hub and a threaded boss are the same thing.

There is nothing in the NEC that would require the use of a hub, however there are a few that would permit the use of a hub to accomplish the requirement of the code, such as weather proofing and assured bonding.
 
Re: Myers Hubs

NEC requires that you meet the environmental demands.
Nema-3R tests use a simulated wind-blown rain. Nema-4 use a hose from all angles. Ordinard "compression" type connectors do nothing to seal the interface between the fitting and the enclosure.
For ordinary outdoor locations, this is only a problem on the tops of enclosures; in other orientations, the unsealed area will tend to shed rain of its' own accord.
Where water may come from other directions -say, during a washdown- a Myers' hub ought to be used all around the enclosure.

I consider a Myers' hub to provide adequate bonding. The o-ring is only on one face; the other is serrated. Only in an explosion-proof installation, or when using fiberglass enclosures, do I see a need for bonding jumpers.
 
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