PVC box adapter ? for garage subpanel

[RickP]

I'm using a box adapter to add a junction to an LB conduit body:

Is that the right way to use a coupling with a box adapter? Like this one:

Thanks. I've used PVC conduit before, but I've never used a box adapter in a conduit body. And this is my first subpanel install.

 

[RickP]

Adding garage subpanel

Background: I'm adding a subpanel in my attached garage, with 4 circuits (welder, compressor and two outdoor 120V runs).

Here's the first circuit for a welder -- feed is from the top, using 6-3 romex: (with a 50A breaker in the main panel 100' away)

And the neutral bar is isolated from the box:

The 50A outlet for the welder is just below the LB conduit body -- it's fed with a piece of the same 6-3 NM-B cable:

Does that wiring look okay?

 

[zmaxmotorsports]

What is the lb connected to inside of wall? Overall it looks like a pretty neat install from what I see in the pictures.

 

[nadogail]

What will that outlet fasten to?

I don't see a box in the drywall.

 

[RickP]

What is the lb connected to inside of wall? Overall it looks like a pretty neat install from what I see in the pictures.

Thanks.

Do you mean the LB in the first photo? That's going through the wall to a box on the outside wall of the garage -- the one on the left in this overall view:

 

[zmaxmotorsports]

What will that outlet fasten to?

I don't see a box in the drywall.

He doesnt have a plaster ring on there yet.

 

[RickP]

Welder outlet

What will that outlet fasten to?

I don't see a box in the drywall.

It's a deep 4" square box. Here's a better photo of it:

 

[wyliesdiesels]

Is that the right way to use a coupling with a box adapter? Like this one:

Thanks. I've used PVC conduit before, but I've never used a box adapter in a conduit body. And this is my first subpanel install.

Thats a reducer not a terminal adapter.

I wouldve changed the LB to a J box.

u should use a terminal adapter (pictured below) with a lock ring:

 

[RickP]

I think the other 3 circuits were pretty straightforward. I pulled 8 gauge THHN for a 40A compressor circuit, and 12 gauge for two 20A circuits -- all pulled through the conduit on the right side of the panel:

That conduit actually has 270 degrees of bends behind the access panel, to get to the LB. I was getting pretty close to full on the 3/4 inch conduit, so I decided to only pull one neutral for the 120V circuits. I'll make them a multi-wire branch circuit (MWBC) and add a common trip handle tie when I hook them up.

 

[wyliesdiesels]

What is the HP rating of the compressor?

 

[RickP]

Thats a reducer not a terminal adapter.

I wouldve changed the LB to a J box.

I'm confused -- it was labeled "box adapter" when I grabbed it off the shelf. Here's the Carlon web page for it:

"Application: Adapts non-metallic conduit to all electrical enclosures by inserting adapter through knockout and cementing into Carlon couplings."

Link: http://www-public.tnb.com/ps/fulltilt/index.cgi?part=E996ERCTN

But you're right -- I probably should have used a J box instead. If I'd used a box, would that have been the right use for a box adapter?

Here's a comparison of the box adapter (left) and a reducing bushing (right):

They're very close in size, and they look pretty interchangeable to me, except the R.B. has a stop at the bottom end for the 1/2-inch conduit.

 

[RickP]

What is the HP rating of the compressor?

It's the 5hp compressor from HF, under the U.S. General name. The motor nameplate says 22.0 amps.

I figured I could use 10 gauge wire for that size motor, and upsize the breaker to 40A. I think you actually helped me figure out the wire size about a year or so ago. I've had it running with a temporary hookup since then.

But I decided to pull 8 gauge wire to the J box for the 40A circuit, just in case I ever put an outlet there instead. For this compressor, I've got it wired direct using a 10 gauge Liquid-Tite whip from Home Depot.

Here's the wiring for the compressor:

I wasn't sure the insulating bushings were needed, but I had a few extras, so I used them.

 

[wyliesdiesels]

I'm confused -- it was labeled "box adapter" when I grabbed it off the shelf. Here's the Carlon web page for it:

"Application: Adapts non-metallic conduit to all electrical enclosures by inserting adapter through knockout and cementing into Carlon couplings."

Link: http://www-public.tnb.com/ps/fulltilt/index.cgi?part=E996ERCTN

But you're right -- I probably should have used a J box instead. If I'd used a box, would that have been the right use for a box adapter?

The more i look at it on my small phone i think youre right.

On my dim screen it looked like a reducer to me....

It's the 5hp compressor from HF, under the U.S. General name. The motor nameplate says 22.0 amps.

I figured I could use 10 gauge wire for that size motor, and upsize the breaker to 40A. I think you actually helped me figure out the wire size about a year or so ago. I've had it running with a temporary hookup since then.

But I decided to pull 8 gauge wire to the J box for the 40A circuit, just in case I ever put an outlet there instead. For this compressor, I've got it wired direct using a 10 gauge Liquid-Tite whip from Home Depot.

Yeah #10 THHN wouldve worked. #8 is good to 50a.

 

[RickP]

The more i look at it on my small phone i think youre right.

On my dim screen it looked like a reducer to me....

Yeah #10 THHN wouldve worked. #8 is good to 50a.

Thanks.

I just added a photo to post #11 above, comparing the box adapter to a reducing bushing -- they're almost identical. But Carlon has different model numbers molded into them:

Box Adapter: E996E

Reducing Bushing: E950ED

 

[RickP]

I used a 1/2-inch liquid-tite whip to hookup the compressor:

I don't have any good ideas for the access panel -- I'd like to seal it up, but be able to get in there someday if I need to change any circuits:

Any suggestions for covering the rough cut edges of the drywall? (It's just resting there now.)

 

[FordTruckWench]

Re: Welder outlet

It's a deep 4" square box. Here's a better photo of it:

If you had used a box like this one:

then you could have used a cover like this:

This way you wouldn't have the rough drywall edge around the receptacle box.

 

[RickP]

I thought about that -- but the cover I used is 3x thicker and that welder plug is really brutal on the outlet when I'm plugging it in. Originally, the box was flexing too much, even after attaching it to the 2x6 stud with six drywall screws! But I added a 14.5" cross brace between the studs and drove one screw into it through the top of the box.

I'm going to use some drywall mud and tape to clean up the edges (when I get around to patching the hole in the wall from my compressor almost sliding off its temporary support last week, while I was changing out the drain valve on it...)