PVC service masts

[kwired]

The meter socket enclosure is governed by Article 312, and 312.2 says "For enclosures in wet locations, raceways or cables entering
above the level of uninsulated live parts shall use fittings listed for wet locations."

So the top entry needs to use fittings listed for wet locations.

Cheers, Wayne

And these hubs are, but at same time any raceway connected to it will allow more water that forms from condensation in the raceway to drain into the meter socket than will ever leak through any fitting , even some set screw fittings hold out reasonably well compared to what forms inside from condenstation in my experiences. Not that I intentionally install them but have come across existing that has held up pretty well.

 

[wwhitney]

And these hubs are,

OK, but if the hub is only listed for use with IMC and RMC, then I would say 312.2 requires that you only use them with IMC and RMC.

Although functionally, they should work just as well with a tapered PVC MA. So that would just be a listing issue, not a function issue. While with a straight PVC MA, there is a functional issue, it will not see as well as tapered threads.

Cheers, Wayne

 

[kwired]

OK, but if the hub is only listed for use with IMC and RMC, then I would say 312.2 requires that you only use them with IMC and RMC.

Although functionally, they should work just as well with a tapered PVC MA. So that would just be a listing issue, not a function issue. While with a straight PVC MA, there is a functional issue, it will not see as well as tapered threads.

Cheers, Wayne

This industry loves confusion it seems.

Raintight EMT connectors are supposed to be rated to directly install in a drilled KO in a box/cabinet, using that stupid cheap gasket they come with. I stopped using those and gone back to using myers hubs with them even though not listed for it. That gasket doesn't even last a year in many cases and leaves not only the water tightness of the assembly in question but also grounding/bonding integrity.

Any inspector that wants to reject it better watch out, he likely to be buried in a deep hole with a pallet full of rain tight connectors as well.

 

[hbiss]

The closest thing I can find is that 352.30 says "PVC conduit shall be . . . fastened so that movement from thermal expansion or contraction is permitted." Do metal and plastic 2 hole straps differ in that regard?

Cheers, Wayne

I was thinking the same thing. Depends on the length, but you don't have to sock the screws down so tight that the conduit can't move if it is going to.

-Hal

 

[jap]

If I don't want a riser to buckle and look like crap, I don't use PVC.

If I do use PVC I generally strap mine down enough that I've never really had to worry with it.

If there are some that worry about their riser deforming due to expansion and contraction, and, have the time on their hands to sit and watch it happen, at least I've left them with something to entertain themselves.

JAP>

 

[kwired]

If I don't want a riser to buckle and look like crap, I don't use PVC.

If I do use PVC I generally strap mine down enough that I've never really had to worry with it.

If there are some that worry about their riser deforming due to expansion and contraction, and, have the time on their hands to sit and watch it happen, at least I've left them with something to entertain themselves.

JAP>

Generally all you need to do is come back a few months later, if it had significant expansion/contraction, it probably no longer straight and may even have broken fittings.

If you strap the hell out of it all that pressure is ultimately going to work on something and break it eventually.

I was thinking the same thing. Depends on the length, but you don't have to sock the screws down so tight that the conduit can't move if it is going to.

-Hal

I see no problem if you wish to use slightly oversized straps either. Isn't that pretty much exactly how you support it if you were routing it through bored holes in framing members?

 

[jap]

Generally all you need to do is come back a few months later, if it had significant expansion/contraction, it probably no longer straight and may even have broken fittings.

If you strap the hell out of it all that pressure is ultimately going to work on something and break it eventually.

I see no problem if you wish to use slightly oversized straps either. Isn't that pretty much exactly how you support it if you were routing it through bored holes in framing members?

You've had a rough go at this electrical stuff K-wired.

I've never had one of my risers break anything in over 40 years so I'd have to politely disagree.

JAP>

 

[hbiss]

I see no problem if you wish to use slightly oversized straps either. Isn't that pretty much exactly how you support it if you were routing it through bored holes in framing members?

The problem with PVC is it flexes and sags and you want to make it look nice where it can be seen. I don't know if there are "slightly oversized" straps available, going to the next size up is usually way too big. (Maybe a next size up EMT strap will work?) I just leave the screws a little loose.

-Hal

 

[jap]

The problem with PVC is it flexes and sags and you want to make it look nice where it can be seen. I don't know if there are "slightly oversized" straps available, going to the next size up is usually way too big. (Maybe a next size up EMT strap will work?) I just leave the screws a little loose.

-Hal

The actual problem with PVC is it's not made to look nice when run exposed.

It's best left underground and out of sight.

JAP>

 

[Dennis Alwon]

A 2" Pvc riser strapped appropriately is fine. It doesn't sag because it is run vertically not horizontally. I haven't done many of them but I have not had an issue with the install.

 

[jap]

A 2" Pvc riser strapped appropriately is fine. It doesn't sag because it is run vertically not horizontally. I haven't done many of them but I have not had an issue with the install.

Me either Dennis. and that's about the only place I use 2" pvc exposed.

Usually a pole mounted service left at the site that the power company ends up hanging anyway.

JAP>

 

[mtnelect]

The actual problem with PVC is it's not made to look nice when run exposed.

It's best left underground and out of sight.

JAP>

I agree ... I only use it where it isn't exposed to the sun.

 

[kwired]

You've had a rough go at this electrical stuff K-wired.

I've never had one of my risers break anything in over 40 years so I'd have to politely disagree.

JAP>

I haven't had much for incidents myself. Have seen 1/2 or 2/4 PVC run up a pole though (why IDK, I'd almost always run a metal raceway in those instances) that were from an enclosure near the base and end at a weatherhead at top. Metal straps - yet it still looks like a snake running up that pole, and the TA at the bottom usually is also broken, presumably from strain imposed on it.

PVC expands and contracts with temp change, if you put a strap every foot, it still going to expand, what happens if you strapped it to the point it can't? IDK, has to be some pretty extreme pressure on something somewhere I would think, whatever is weakest link whether it be a strap, fitting or in wall of conduit itself, would presumably be first thing to give up.

 

[jap]

I haven't had much for incidents myself. Have seen 1/2 or 2/4 PVC run up a pole though (why IDK, I'd almost always run a metal raceway in those instances) that were from an enclosure near the base and end at a weatherhead at top. Metal straps - yet it still looks like a snake running up that pole, and the TA at the bottom usually is also broken, presumably from strain imposed on it.

PVC expands and contracts with temp change, if you put a strap every foot, it still going to expand, what happens if you strapped it to the point it can't? IDK, has to be some pretty extreme pressure on something somewhere I would think, whatever is weakest link whether it be a strap, fitting or in wall of conduit itself, would presumably be first thing to give up.

Me too.

JAP>