I realize this is an extremely basic question. The wiring I can handle, I'm just not so good at the 'nuts and bolts' stuff.

I need to attach PVC conduit to the threaded hub at the top of my load center. If the rest of the run is cemented first, screwing it into the hub is obviously impossible. If I screw it in first and then cement the rest of the PVC, then there's no way to undo it later (say for a panel swap) without cutting the PVC and starting over. Also no way to tighten it should the need arise.

If this was pipework I'd use a union to avoid that problem. I don't see any on my existing buildings' runs though. The co-op guys used a rather ugly long stack of reducer bushings because they used smaller conduit than they said they were going to, so that's hardly a good example for me to go by.

What's the normal way to do this?

 

The normal procedure is to use a male terminal adapter with threads glued to the end of the conduit. A locknut inside the panel holds it in place.

Why is there a hub on the panel? Is this panel inside or outside?

 

Doh! Yeah I should have mentioned that this is a Nema 3R box because it's in an outbuilding. Technically indoors but definitely exposed to the elements depending on when someone leaves the sliding doors open. It's a Square D 'outdoor' panel with a type B bolt-on hub.

 

Can you post a pic? You might be able to come into the side of the panel and avoid the hassle. IIRC there is an issue about PVC into a hub code-wise.

 

I'm unable to take a photo at this time, but all my load centers are this model or similar: HOM816L125RB. And then the hubs are sold separately.

There are some large diameter KOs on the lower sides, but that large cap is still gonna be on top looking silly like that. Not to mention a nice place for water to enter. I'll run metal conduit on top _if_ I have to code-wise. Then I'd have to buy metal weatherheads and all that. Ugh.

No, the co-op "pros" ran PVC to my existing ones so maybe I'm fine with bending the rules a bit -- like they did -- if I have to. All I'm asking is if you'd really have to screw it in the hub first and then cement the rest of the pieces up to the weatherhead, becoming a semi-permanent deal.

Edit- Or maybe what you're saying is remove the top cap and use the normal threaded PVC + locknut approach? That's a huge hole in there, maybe 3-4". If you can do that business, then why don't outdoor boxes just have knockouts on top rather than this hub stuff? The previous jobs were spec'd out with hubs and 1.25" PVC by the department head, so this wasn't just some line guys' improvising. LOL this shouldn't be this hard. Maybe it wasn't such a dumb question after all?

 

You could do the same, but how did they seal the pipe to the hub?

Yes, you have to glue up the entire run of PVC, and cut it later if you want to change the panel - unless you can figure out a way to release the conduit from the hub or to remove the hub and attach it to the new panel.

 

I don't know if they even did; I didn't watch closely. I suppose if I did it, I could use duct seal or whatever.

You just gave me an idea though. If one were to unbolt the hub from the panel, drop the panel, then by bending the conduit away from the wall there'd likely be enough clearance to spin the hub off the fixed PVC. Getting the next one to screw on and align perfectly with the bolt holes might be a fuss though. Honestly I'm not anticipating swapping panels all the time.

I was just wondering if I was missing some fancy swivel piece or something. I think I got that answered. Thanks guys.

For my next trick, watch how an amateur attempts to crimp on WR159 squeezeons with a manual crimper while standing on a 20ft ladder leaned against the utility pole. (First attempt.) I may end up on that America's Dumbest Homeowners show.

 

I find that to be a challenge when I can stand on the floor and brace myself against something. I would never attempt it from a ladder -- unless I had a ratcheting crimper, that is.

 

Please don't tell me you are going to tie in an overhead connection to POCO lines.

The are blanks made for Myers hubs.

 

Certainly not! They are my lines. Since they are past the point of demarcation, I own them. It's a farm setup.

And errr... thanks for editing my post above. It was RectorSeal No. 5 that I meant.

Well noted. I'll start with the easy lower ones first. If they go that badly I'll have to pay a trip charge and have a crew do the nastier ones.