200 amp overhead meter pan hub questions.

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jjhoward

jjhoward

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Location
Northern NJ
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Owner TJ Electric
I have installed many residential over head services with 2? PVC screwed into the top of the meter pan?s hub.
Either I have screwed in a male adapter into the meter pan hub then inserted/glued the PVC stick or screwed in a threaded offset and then inserted/glued the PVC stick.

It always seems that PVC thread and the hub thread do not match. But threading RMC into the meter pan?s hub goes fine.

1) Is the thread of the meter pan hub and the PVC thread different?
2) Is screwing the PVC fittings into that metal hub a code violation?
3) Is this connection (PVC to metal hub) not rain tight?

Different question, same meter pan hub:
Does anyone every install caulking or a gasket where the hub sits on the meter pan surface?

I have a year old install, & it seems like water is getting into the panel via that damn hub. Looks like the water is either entering the meter pan via the PVC to hub threads or the hub to meter pan interface.


Thank you.
 
jumper

jumper

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3 Hr 2 Min from Winged Horses
Wait a minute, I think I may be wrong, this says a threaded PVC fitting is okay for a hub.

http://ulstandardsinfonet.ul.com/scopes/0651.html

1.17 Externally-threaded adapters (also referred to as terminal adapters) covered by these requirements are fittings intended for joining a length of rigid PVC conduit or elbow or other bend to:

a) The knockout area of a metal box with a metal locknut,

b) A threaded metal hub or fitting on a metal box,

I had this in my head, but you are not bonding with PVC, so it does not apply:

Grounding and Bonding Hubs — Grounding and bonding hubs are
Listed hubs (see DWTT) provided with a Listed grounding or bonding locknut.
They serve in a manner similar to grounding and bonding bushings
except they are only for use with threaded rigid metal and intermediate
metal conduit.
 
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C

copper chopper

Senior Member
Location
wisconsin
what if you start with a 6 inch rigid nipple then a rigid coupling to a pvc terminal adt. (connector) and then pvc pipe..... and a little thread sealing compound couldnt hurt
 
infinity

infinity

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Journeyman Electrician
Here's an article from Mark Ode of UL. In his opinion the only thing that can be threaded into a hub is RMC and IMC. EMT, PVC terminal adapters and SE connectors are not listed to be used with hubs due to their straight threads. If his assessment is accurate, 90% of all the service installations around here are violations.

http://www.ecmag.com/?articleID=11585&fa=article
 
jumper

jumper

Senior Member
Location
3 Hr 2 Min from Winged Horses
infinity said:
Here's an article from Mark Ode of UL. In his opinion the only thing that can be threaded into a hub is RMC and IMC. EMT, PVC terminal adapters and SE connectors are not listed to be used with hubs due to their straight threads. If his assessment is accurate, 90% of all the service installations around here are violations.

http://www.ecmag.com/?articleID=11585&fa=article
Click to expand...

But that is for bonding issues. If the PVC adaptor is made water tight, it is not an issue.
 
masterinbama

masterinbama

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Location
Huntsville Alabama
Do not caulk or seal the hub to pan contact point. Most hubs are designed so any water that gets past the threads or condenses inside the riser (what I suspect in this case) will wick along the inside of the hub to the top of the pan. It will then leak out harmlessly. If you seal this area you are forcing the water into the pan.
 
infinity

infinity

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Location
New Jersey
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Journeyman Electrician
jumper said:
But that is for bonding issues. If the PVC adaptor is made water tight, it is not an issue.
Click to expand...


I'm only stating what Mr. Ode said and that's the only permitted entry into a hub is RMC and IMC. For two reasons, bonding when the entry is metallic and the wet location rating when the installation is in a wet locations. IMO the fault here lies with UL and their testing methods. Since a great majority of hubs will be used with other than RMC and IMC then the testing method as part of the hub's listing should include all possible entries into the hub.
 
S

satcom

Senior Member
jumper said:
But that is for bonding issues. If the PVC adaptor is made water tight, it is not an issue.
Click to expand...

Yes that is for bonding issues, for years we used straight thread on all electrical conduit assembly, then they changed to tapered thread, thinking the taper would make a better seal connection, the meter seal issue was never addressed over the years, so the real wrong condition is not the PVC to hub but rather tapered rigid to hub for wet location use
Not to worry, PVC to hub is a good fit, however we had a homeowner use a PVC. Plumbing fitting on a meter hub and the water just poured thru, never saw a problem with electrical PVC terminal and hub.
 
jjhoward

jjhoward

Senior Member
Location
Northern NJ
Occupation
Owner TJ Electric
This one meter pan hub w/PVC 2" male adapter screwed into is allowing water to come right in.
Seems like the water is getting between the hub-meter pan area, not the threaded boss.
The water is getting on the SEU conductors on the load side of the meter and of course goes right into the panel. LOTS of water.
Just spraying a little water on the top of the meter pan produces a constant run of water down the conductors at the top of the meter where it drips onto the load side SEU cable.

I sealed the hub-meter pan seam with plumbers epoxy. I guess I am locking in condensation.:) That would be an improvement over the inches of water getting into the panel.
 
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