Meyer's Hub

Status
Not open for further replies.
ryan_618

ryan_618

Senior Member
Location
Salt Lake City, Utah
For the purposes of 250.92(B)(2) and (B)(4), would you call a Meyer's hub a "threaded boss on an enclosure"? Would you say that they utilize "standard locknuts"? Would you say you need a bond bushing on a Meyer's hub if it is on the line side of a service?
 
ryan_618 said:
For the purposes of 250.92(B)(2) and (B)(4), would you call a Meyer's hub a "threaded boss on an enclosure"? Would you say that they utilize "standard locknuts"? Would you say you need a bond bushing on a Meyer's hub if it is on the line side of a service?
Click to expand...

1. No

2. Yes, although the contact surface is larger

3. Yes
 
ryan_618 said:
For the purposes of 250.92(B)(2) and (B)(4), would you call a Meyer's hub a "threaded boss on an enclosure"? Would you say that they utilize "standard locknuts"? Would you say you need a bond bushing on a Meyer's hub if it is on the line side of a service?
Click to expand...

Yes. I think the term "threaded boss" is to be clear that it is NOT an emt connector or an FA (for pvc). (In foundry terms: "A projection of circular cross-section on a casting. Usually intended for drilling and tapping for attaching parts.)

As to the bond bushing... No. The four bolts through the enclosure do that.
 
Just so we are all speaking the same language:
images

images

images
 
THe critter you picture is also what I call a Myers Hub. To me, it meets the requirements of 250.92 without requiring a bonding locknut or bushing, and I do not consider any part of it a "standard locknut"
 
I also call Rob's picture a Myers Hub but the ones that I normally use are a little different. They are Red Dot's HTZ series hubs.

For this style there is not a way to put a bonding bushing on them.
 
C3PO said:
I also call Rob's picture a Myers Hub but the ones that I normally use are a little different. They are Red Dot's HTZ series hubs.

For this style there is not a way to put a bonding bushing on them.
Click to expand...

never heard of "JB WELD" ? :D

inspector wants a bushing:smile:
 
Karl H said:
A Meyers Hub has a rubber O-Ring. I say a bonding bushing is required.
Click to expand...

Obviously, there is more than one manufacturer, but on, the ones I have used, the O ring is recessed enough that the "teeth" of the hub still bite into the enclosure. To me, and perhaps only me, that is sufficient.
 
augie47 said:
Obviously, there is more than one manufacturer, but on, the ones I have used, the O ring is recessed enough that the "teeth" of the hub still bite into the enclosure. To me, and perhaps only me, that is sufficient.
Click to expand...

same here.

i don't think a bonding bushing is required.

that's what the teeth are for, right?
 
augie47 said:
Obviously, there is more than one manufacturer, but on, the ones I have used, the O ring is recessed enough that the "teeth" of the hub still bite into the enclosure. To me, and perhaps only me, that is sufficient.
Click to expand...

I just looked at one on my truck and it does seem to have 5 threads
in contact as well. Still the O-Ring isn't recessed enough IMO because
if it were it wouldn't be rain tight.
 
Karl H said:
I just looked at one on my truck and it does seem to have 5 threads
in contact as well. Still the O-Ring isn't recessed enough IMO because
if it were it wouldn't be rain tight.
Click to expand...

the o-ring compresses when you tighten the hub, giving you full contact of the metal surface with the enclosure, and a water seal.
 
While I agree that a myers hub is not a thread boss and some form of bonding would be required if you used it for a service raceway, it is my opinion that a myers hub provides a better bonding path than a meter hub where the bonding path is really just the screw threads.
 
IMO, I would agree that the lock nut that comes with a "standard male 'Myers' hub" fitting is a trade standard lock nut. However, in the past I have used female Myers hubs that do not include a locknut as part of its standard assembly.

Some male Myers hubs come with a bonding style locknut.
 
Status
Not open for further replies.
Top