Bushings required on PVC

[jkrauss]

I was ask to help out on a large wire pull , before we stared the pull I notice that there was no
Bell end or bushing installed on the ends of the PVC .I ask the Forman about it and I was told
They were not needed on PVC. Article 300.4 G says where # 4 or larger is installed in a raceway
A identified fitting shall be installed on the raceway To protect the conductor . My question is a
fitting required on PVC conduit that contains #4 and larger conductors? (The conduit were stubs
Up out of a concrete floor in switchgear )

 

[kwired]

I read it as meaning that all raceways containing conductors larger than 4 AWG need a busing or a fitting that provides equivalent abrasion protection.

 

[Dennis Alwon]

Now read 352.46 and it is not so clear

 

[kwired]

Now read 352.46 and it is not so clear

What is not so clear, and applies to other types of raceway fittings also is just what is considered equivalent protection.

There are fittings with insulated throats, I think most of them are intended to be providing equivalent protection.

There are some fittings with pretty smooth rounded edges, and there are others that are not so smooth.

About the only thing that is clear is that threaded RMC and IMC need a bushing for all conductor sizes.

Maybe the fitting manufacturer has literature indicating whether or not the particular fitting provides equivalent protection? IDK I have never really looked into this.

 

[jkrauss]

Informational note says se 300.4 for protection of conductors #4 and larger at bushings I think
352.46 refers to a box or enclosure with manufacture hubs like a fs box or bell box

 

[Dennis Alwon]

One section says 4 or larger but this appears to apply to all pvc runs unless it is a threaded entry or a fitting that is rounded such as a box slip fitting- looks like a chase nipple with no threads.

 

[Dennis Alwon]

Informational note says se 300.4 for protection of conductors #4 and larger at bushings I think
352.46 refers to a box or enclosure with manufacture hubs like a fs box or bell box

No I don't think so. 352.46 refers to pvc entering a box -- where do you get the hub statement?

 

[infinity]

Here's a graphic from Mike Holt:

 

[Dennis Alwon]

Here's a graphic from Mike Holt:

That is typically what we do however I don't believe it is written that way for PVC

 

[kwired]

Here's a graphic from Mike Holt:

Exactly what I have always known the requirements to be. I totally understand the "any size" conductor for threaded RMC or IMC.

I never understood why abrasion protection is needed for 4AWG and larger. I can damage insulation of any size conductor on a fitting edge if I don't take some care of how I handle it during installation.

 

[jkrauss]

No I don't think so. 352.46 refers to pvc entering a box -- where do you get the hub statement?

Your right 352.46 refers to PVC some PVC junction boxes have molded hub built in to them

 

[jkrauss]

Here's a graphic from Mike Holt:

Thanks the graphic answers my ?

 

[Dennis Alwon]

Your right 352.46 refers to PVC some PVC junction boxes have molded hub built in to them

Where does it state PVC JB's. It just states jb. The graphic is what we all go by and I am sure that is the intent of 352.46 but I don't see it saying that. Maybe a proposal is in store.

 

[kwired]

Where does it state PVC JB's. It just states jb. The graphic is what we all go by and I am sure that is the intent of 352.46 but I don't see it saying that. Maybe a proposal is in store.

352.46 says "Where a conduit enters a box, fitting, or other enclosure" which IMO includes just about every possible termination except for in free air. Now when it comes to PVC we don't terminate in a box unless it is a box where we cement the raceway into the box hub, we terminate into a "terminal adapter" which we then use to connect to the box, fitting or other enclosure. Even more confusion now, as the terminal adapter is not raceway it is a fitting. I'd like to see somebody put a bushing on the raceway and not the fitting in these instances (or maybe not).

 

[jkrauss]

This pvc conduit did not enter a jbox it just stub up out of the floor ,Typically when I stub up in
to a switch gear with a open bottom siting on a pad I put a bell end on the conduit . I also install bell ends on PVC when they enter manholes .as per article 300.4G

 

[hardworkingstiff]

This pvc conduit did not enter a jbox it just stub up out of the floor ,Typically when I stub up in
to a switch gear with a open bottom siting on a pad I put a bell end on the conduit .

Same here. I have installed a TA and bushing if the bell adapters were not available.

 

[kwired]

This pvc conduit did not enter a jbox it just stub up out of the floor ,Typically when I stub up in
to a switch gear with a open bottom siting on a pad I put a bell end on the conduit .

It is still entering a box, fitting, or other enclosure isn't it? May not be attached to that box, fitting or other enclosure but is entering.

 

[jkrauss]

I agree

 

[Dennis Alwon]

This pvc conduit did not enter a jbox it just stub up out of the floor ,Typically when I stub up in
to a switch gear with a open bottom siting on a pad I put a bell end on the conduit . I also install bell ends on PVC when they enter manholes .as per article 300.4G

Perfectly compliant in my eyes. Many inspectors will alow a pvc coupling on the end as it has smooth edges.