Want to verify how to connect to an existing PVC box

[Installer]

I'm working with an electrician that's an absolute perfectionist. We need to make a new run off of an existing PVC box and I want to verify that this is the best way to do it.
On the top is what we have.
On the bottom is what we would like to do.
Is this correct?
Is there a better way to do it?


Thank you in advance

 

[LarryFine]

How about a standard male adapter and locknut?

 

[JFletcher]

How about a standard male adapter and locknut?

That's how I would do it... That maybe the only way to do it... Never seen PVC glued into a box unless it had bosses / smooth hubs design to be glued into.

Bringing a 2 inch conduit into what appears to be a 6 inch square box... box fill comes to mind too.

 

[MAC702]

I don't think I'm picturing it very well. Where is the lid for access inside the box? Are you surface-gluing a flange onto a flat surface?

 

[hbiss]

Where did you find that "flange"? I don't recall any electrical fitting like that.

Is this an outdoor location?


-Hal

 

[LarryFine]

That "flange" is intended to be installed from inside the enclosure, and glued into a coupling. It would eliminate the need for a plastic bushing.

 

[hbiss]

That's what I suspect, a box adapter. It's made to be inserted through a proper sized hole in the box then mate with a coupling on the end of the conduit on the outside. The OD is the same as that of the conduit so inserting the conduit into it like your drawing isn't going to work.

Something like what your boss proposes is only going to win him a picture in ECN's "What's wrong here". :happyyes:

-Hal

 

[Installer]

Its a 2" PVC Box Adapter

Its a 2" PVC Box Adapter

The top of the PVC box is flat.

I thought --perhaps wrongly--that you got a 2" hole saw and then used PVC cement to glue this on the inside face of the enclosure. Was I that off base?

 

[infinity]

The top of the PVC box is flat.

I thought --perhaps wrongly--that you got a 2" hole saw and then used PVC cement to glue this on the inside face of the enclosure. Was I that off base?



View attachment 21442

Wet or dry location? Can those be used in wet locations?

 

[Installer]

That's what I suspect, a box adapter. It's made to be inserted through a proper sized hole in the box then mate with a coupling on the end of the conduit on the outside. The OD is the same as that of the conduit so inserting the conduit into it like your drawing isn't going to work.

Something like what your boss proposes is only going to win him a picture in ECN's "What's wrong here". :happyyes:

-Hal

I'm not that smart but I'm not that out of it either, I would have realized it when I went to assemble it LOL

 

[Installer]

Wet or dry location? Can those be used in wet locations?

Yes that's definitely a concern ! Can I? I though the PVC bond was water tight? Is it? Thanks in advance because this is outdoors

 

[MAC702]

Yes that's definitely a concern ! Can I? I though the PVC bond was water tight? Is it? Thanks in advance because this is outdoors

There is no PVC bond between the box and the adapter. Indeed, I often see these not even inserted sufficiently into the coupling to not be loose. This is probably because it gets glued and then inserted, and only then do you realize you have no good leverage to fully insert it and nothing to push it against. In the time it takes to say "Well, crap," there you are and it's done.

At least with a male threaded adapter, one can use a rubber washer and the lockring can be snugged, for as long as it lasts anyway. If you need the clearance of the flanged box adapter, you can do the same thing with a threaded female adapter and use a chase nipple on the inside. But you will have less of a shoulder for a rubber washer if one is desired.

What is the orientation of the box? Is the opening on the bottom?

 

[hbiss]

There is no PVC bond between the box and the adapter. Indeed, I often see these not even inserted sufficiently into the coupling to not be loose. This is probably because it gets glued and then inserted, and only then do you realize you have no good leverage to fully insert it and nothing to push it against. In the time it takes to say "Well, crap," there you are and it's done.

I think that if you either support or put pressure on the box adapter from inside the box while you press the coupling into place and apply the glue (to the adapter and the inside and bottom of the coupling) so that it flows out between the coupling and the box (essentially welding the coupling to the box) I think you will have a mechanically sound and waterproof connection. Key here is to press them together long enough for the glue to set. I'm thinking blocks of wood and a clamp.

Now you have a coupling attached to the box that looks like one of the hubs ready to accept the conduit.

-Hal

 

[Installer]

I think that if you either support or put pressure on the box adapter from inside the box while you press the coupling into place and apply the glue (to the adapter and the inside and bottom of the coupling) so that it flows out between the coupling and the box (essentially welding the coupling to the box) I think you will have a mechanically sound and waterproof connection. Key here is to press them together long enough for the glue to set. I'm thinking blocks of wood and a clamp.

Now you have a coupling attached to the box that looks like one of the hubs ready to accept the conduit.

-Hal

Thank you. I was just about to ask that question. That was the whole reason I wanted to try the PVC box adapter. In my limited experience, its a cardinal sin to leave the top of a box with a threaded fitting with a sealing ring and star washer because the sealing washer will eventually fail. I always place them at the bottom. That's why I wanted to go with the PVC approach, but I needed some professional feedback.

My plan was to gently sand the PVC to get good a clean weld and use some heavy duty PVC adhesive. From working on my bathroom I kind of remember seeing some PVC prep compound.

Thank you

 

[Russs57]

I think you be better off with a "myers hub". AKA, conduit hub. Reckon you could look at "bulkhead fittings" as well.

 

[jumper]

I think you be better off with a "myers hub". AKA, conduit hub. Reckon you could look at "bulkhead fittings" as well.

Agree.

 

[infinity]

I like the idea of the PVC box adapter but technically if used in a wet location it has to be listed for wet locations. Also not sure what you pulling in this raceway but keep in mind the 6X rule for an angle pull if you're using #4 or larger conductors.

 

[Installer]

Myers Hub

Myers Hub

I think you be better off with a "myers hub". AKA, conduit hub. Reckon you could look at "bulkhead fittings" as well.

You mean this thing? I'm willing to try it, but that washer is going to..

 

[roger]

View attachment 21454


You mean this thing? I'm willing to try it, but that washer is going to..

250.148(D) is also relevant if you use a metallic fitting.

Roger

 

[LarryFine]

View attachment 21454


You mean this thing? I'm willing to try it, but that washer is going to..

Actually, that is for connecting conduits to both sides while passing through a barrier of some type, sorta like a coupling.

A Myers hub like we're talking about is functionally more like a connector than a coupling: