Myers Hub

[scnkapc]

Situation: Existing MDP outside. They are adding new sub-panels outside. Running RMC from the top of MDP to the top of sub-panels using raised hub provided with Nema 3R panel.

The existing RMC emerges from MDP by means of a ?Myers Hub?.

Are they required on the new RMC that are going to feed the new sub-panels? Aren?t sealing lock nuts enough?

What situation requires a "Myers Hub" to be installed?

Please provide code article as reference.

 

[petersonra]

Situation: Existing MDP outside. They are adding new sub-panels outside. Running RMC from the top of MDP to the top of sub-panels using raised hub provided with Nema 3R panel.

The existing RMC emerges from MDP by means of a ?Myers Hub?.

Are they required on the new RMC that are going to feed the new sub-panels? Aren?t sealing lock nuts enough?

What situation requires a "Myers Hub" to be installed?

Please provide code article as reference.

The code does not specify brand names.

 

[Dennis Alwon]

Myers hubs are just one means of attaining a weather tight connection. Sealing locknuts are also listed for the purpose with RMC. From the UL book

Sealing (Liquid-tight) Locknuts — Sealing locknuts are intended for use with threaded rigid metal conduit and intermediate metal conduit with one sealing locknut in the outside or the inside and either an ordinary locknut or sealing locknut on the inside of the enclosure for wet locations or liquidtight applications. Sealing locknuts may also be used with Listed wet location or liquid-tight fittings where so marked on the fitting carton and used on the inside of the enclosure.

 

[scnkapc]

I know they are a brand name. What is their purpose if that type of fitting is not required anywhere? Why do we use them?

 

[Dennis Alwon]

I know they are a brand name. What is their purpose if that type of fitting is not required anywhere? Why do we use them?

Did you read my post. You can use the sealing locknut

 

[infinity]

Look at 312.2. As Dennis said either a "Myers" hub or sealing locknut is permitted.

 

[jeremysterling]

I know they are a brand name. What is their purpose if that type of fitting is not required anywhere? Why do we use them?

You can tighten the locknut on the Myers hub without turning the gasketed side.

The myers hub will not need a plastic bushing.

The myers hub o-ring design is a significant improvement over the flimsy easily ripped sealing locknut.

Check out the female myers hub. Functions like a PVC box adapter. They can come in handy in tight situations.

 

[petersonra]

A Myers type hub has two big advantages in my mind. They make a really good bonding connection, and they are really water tight.

The gaskets are cheaper but not as secure and seem to leak on a regular basis.

 

[augie47]

A Myers type hub has two big advantages in my mind. They make a really good bonding connection, and they are really water tight.

The gaskets are cheaper but not as secure and seem to leak on a regular basis.

agree.
I have observed sealing locknuts that allowed water entry. I have not seen a "myers" hub that did.

 

[tom baker]

A Myers type hub has two big advantages in my mind. They make a really good bonding connection, and they are really water tight.

The gaskets are cheaper but not as secure and seem to leak on a regular basis.

A meyers hub is not listed for grounding. There is a lock nut for the meyers hub with a bonding screws if bonding is required.

 

[infinity]

A meyers hub is not listed for grounding. There is a lock nut for the meyers hub with a bonding screws if bonding is required.

Do you mean service raceway grounding or grounding in general?