Correct glue for ENT and PVC connection

[stardog]

Using a standard PVC coupling I will be connecting 1/2" ENT flexible tubing to 1/2" schedule 40 PVC. I plan on using plain Oatey gray PVC solvent to do so. I presume this would be the correct solvent for this application? If not, then which solvent should I use? I need to connect the two for a short run of ENT inside the attic.

I believe Carlon recommends a blue cement for strictly ENT>ENT connections, but not sure for ENT to PVC. Tks.

 

[wwhitney]

Any PVC solvent cement should work fine, I think, although Carlon's spec requires the use of their blue ENT cement.

An alternative is that Carlon makes a Schedule 40 hub x ENT male snap fitting, part A236D for 1/2". You'd use the male snap end with a snap coupling, part A240D for for 1/2", to connect to a run of ENT. If the ENT goes to your box, you can terminate it at the box with either a male adapter, part A243D for 1/2", or a snap in box adapter, part A253D for 1/2". Not sure what the box wall thickness range is for the snap in box adapter.

Of course, all those snap connections are just for convenience. You can use regular schedule 40 fittings with PVC solvent cement on ENT.

Cheers, Wayne

 

[Sponsor]

 

[stardog]

Any PVC solvent cement should work fine, I think, although Carlon's spec requires the use of their blue ENT cement.

An alternative is that Carlon makes a Schedule 40 hub x ENT male snap fitting, part A236D for 1/2". You'd use the male snap end with a snap coupling, part A240D for for 1/2", to connect to a run of ENT. If the ENT goes to your box, you can terminate it at the box with either a male adapter, part A243D for 1/2", or a snap in box adapter, part A253D for 1/2". Not sure what the box wall thickness range is for the snap in box adapter.

Of course, all those snap connections are just for convenience. You can use regular schedule 40 fittings with PVC solvent cement on ENT.

Cheers, Wayne

 

[stardog]

Wayne,

Thanks very much for your quick response, it's the news I wanted to hear. I have three small electrical projects in the attic that require short runs of flexible cable from PVC conduit in order to conveniently reach the j-boxes. I've never had ocasion to use flexible tubing before, but after reading up on it, it certanly looks pretty straght forward enough.

 

[wwhitney]

A few more pointers for you in case they are helpful:

- Any conduit run is limited to 360 degrees of bend between pull points, so you'll have to estimate the degrees of bend in your ENT portion and add that in.

- I hear ENT is harder to pull through than Schedule 40, so that would be one reason to pull so that the ENT is encountered at the end of the run. But in general it is easier to pull with gravity rather than against, which would put ENT in the attic at the beginning of the run. Not sure which is a bigger factor. If you have multiple runs to do, you can try it both ways and let us know. : - )

- Depending on the details you could put multiple circuits in one conduit.

- Also, 3/4" might be easier to pull through and should not be much more expensive/difficult to work with.

Cheers, Wayne

 

[stardog]

Actually I gave a lot of serious thought to running two circuits (totaling six 12 AWG wires) thru one 1" conduit from the panel, but then couldn't figure out how to easily split them apart in the attic in order to direct them to two separate junction boxes. Unless you are aware of some type of 1" PVC coupling that I could attach to the main conduit coming into the attic that would enable me to split the final runs in two different directions. The same principal as a cable splitter I suppose. Then at that point I could connect two separate pieces of flexible tubing and direct each where it needs to go. Always open to creative problem solving, as mine fails me sometimes. I even thought of attaching a 1" Type T conduit body to the end in the attic, which would essentially give me two additional openings to utilize in order to run flexible cable in two different directions from a central point.

 

[wwhitney]

(2) 2-wire circuits would only require 5 wires in the conduit, there's generally no reason to run double EGCs. I think (5) #12s would easily fit in 3/4", you could check. And if these circuits are 120V, and don't require AFCI or GFCI protection, then you could run them as a s ingle MWBC with just 3 circuit conductors (4 total wires).

The simplest way if the boxes aren't too far apart is simply to run both circuits to one box, then continue the second circuit to the other box. (You just have to be careful of box fill.) The alternative is what you suggest, the T conduit body, that is what they are for. You can even splice the EGC in the T-conduit body.

BTW, not sure what your attic eave geometry is like, but have you considered the feasibility of this: Drill a hole through the soffit from the outside where you want the PVC riser to come in. Then in the attic, glue an elbow to the end of a piece of conduit, and use the conduit as a handle to guide the other end of the elbow through the hole in the soffit. If the problem is that the angle you need is not 90 degrees, it's not too hard to bend PVC conduit/fittings after careful heating.

Cheers, Wayne