Proper connectors & boxes for PVC jacketed MC in a barn

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toddkrein

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Loomis, California
We're running PVC jacketed MC cable on a new barn build, and using PVC boxes, but I'm unclear what the proper type of box-to-cable connector would be. It's considered damp, not wet, and I need the MC for rat protection. It seems like all the MC-rated connectors I'm finding are metal, and thus subject to the same corrosion that requires the PVC jacket, or way-over-spec direct burial, wet, watertight monstrosities that cost more than the barn.

I'd appreciate any pointers!
 
The boxes have to comply with 314.3

314.3 Nonmetallic Boxes. Nonmetallic boxes shall be permitted
only with open wiring on insulators, concealed knob-andtube
wiring, cabled wiring methods with entirely nonmetallic
sheaths, flexible cords, and nonmetallic raceways.


Exception No. 1: Where internal bonding means are provided between
all entries, nonmetallic boxes shall be permitted to be used with metal
raceways or metal-armored cables.


Exception No. 2: Where integral bonding means with a provision for
attaching an equipment bonding jumper inside the box are provided
between all threaded entries in nonmetallic boxes listed for the purpose,
nonmetallic boxes shall be permitted to be used with metal raceways or
metal-armored cables.
 
packersparky said:
The boxes have to comply with 314.3

314.3 Nonmetallic Boxes. Nonmetallic boxes shall be permitted
only with open wiring on insulators, concealed knob-andtube
wiring, cabled wiring methods with entirely nonmetallic
sheaths, flexible cords, and nonmetallic raceways.


Exception No. 1: Where internal bonding means are provided between
all entries, nonmetallic boxes shall be permitted to be used with metal
raceways or metal-armored cables.


Exception No. 2: Where integral bonding means with a provision for
attaching an equipment bonding jumper inside the box are provided
between all threaded entries in nonmetallic boxes listed for the purpose,
nonmetallic boxes shall be permitted to be used with metal raceways or
metal-armored cables.
Click to expand...

Yes and as I said, a PITA.
 
jumper said:
Just curious, why the PVC coated MC?

I love MC, just not sure I would be using it here.
Click to expand...

Two factors:
1) Rats and Horses - both of which will chew anything they can get to, leads me to either conduit (PVC a/o metal), or a armored cable of some sort
2) Damp - since it's a damp and slightly corrosive environment, regular MC doesn't qualify

So my main alternative is running PVC conduit everywhere, which will take forever, and then I have to pull all the cable, which will take more forever. I'm willing to trade some material cost for labor time.

Now, I could do it in two sections, using the PVC-MC only on/in the (for lack of a better word) main walls, and then switch to something non-MC once I get into the roof, on the theory that horses don't climb, and the rats are far more likely to be near the ground as well, but I don't want to get called back and have to redo it.

But I'm *very* open to suggestions.
 
hbiss said:
I agree. I would do it with EMT and call it a day.

-Hal
Click to expand...

Well, that's actually what the customer asked for, so perhaps it's for the best. I just loath EMT...

What sort of metal box is damp rated, or should I just use Bell boxes? (I'm assuming that a PVC box has the same bonding requirement as when using the MC cable...)

thanks.
 
toddkrein said:
Well, that's actually what the customer asked for, so perhaps it's for the best. I just loath EMT...

What sort of metal box is damp rated, or should I just use Bell boxes? (I'm assuming that a PVC box has the same bonding requirement as when using the MC cable...)

thanks.
Click to expand...

I would tend towards FS/FD boxes in this application myself.

http://www.cooperindustries.com/con...rdous/fs_fd_series_singlegangdeviceboxes.html

Prolly use RMC in the stalls also, horses can be brutal on stuff.

Why do you loathe EMT? Just do not run it a lot?
 
jumper said:
I would tend towards FS/FD boxes in this application myself.

http://www.cooperindustries.com/con...rdous/fs_fd_series_singlegangdeviceboxes.html

Prolly use RMC in the stalls also, horses can be brutal on stuff.

Why do you loathe EMT? Just do not run it a lot?
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Those look great, thanks for the tip. At the moment, no requests for anything *in* the stalls themselves, thank goodness.

I almost never use EMT, since 98% of what I do is low-voltage IT stuff. The other 2% is running an outlet for IT stuff. All my conduit is PVC.

I mostly make spaghetti when it comes to bending EMT, and everything is 1" offset. :ashamed1:
 
toddkrein said:
Two factors:
1) Rats and Horses - both of which will chew anything they can get to, leads me to either conduit (PVC a/o metal), or a armored cable of some sort
2) Damp - since it's a damp and slightly corrosive environment, regular MC doesn't qualify...
Click to expand...

So they will chew through the PVC coating on the MC anyway...

...I mostly make spaghetti when it comes to bending EMT, and everything is 1" offset.
Click to expand...

These really do work well. I've done so many offsets that it's quick and easy, but a friend bought one of these and I tried it on a job we did together. I was impressed.

31k5abbwu3L.jpg


It's a Greenlee Little Kicker.
 
toddkrein said:
Those look great, thanks for the tip. At the moment, no requests for anything *in* the stalls themselves, thank goodness.

I almost never use EMT, since 98% of what I do is low-voltage IT stuff. The other 2% is running an outlet for IT stuff. All my conduit is PVC.

I mostly make spaghetti when it comes to bending EMT, and everything is 1" offset. :ashamed1:
Click to expand...

I rewired a small horse barn a few years ago. (I guess it was small, about 12 stalls) I pulled out the old ungrounded romex and ran uf cable and metal boxes. Didn't even think about rats, but there was no damage I saw on the old cable. No callbacks. MC cable needs to be protected from physical damage. Down below say 4 feet in the barn may not be compliant.
 
GerryB said:
I rewired a small horse barn a few years ago. (I guess it was small, about 12 stalls) I pulled out the old ungrounded romex and ran uf cable and metal boxes. Didn't even think about rats, but there was no damage I saw on the old cable. No callbacks. MC cable needs to be protected from physical damage. Down below say 4 feet in the barn may not be compliant.
Click to expand...

UF would be a violation. You have that 15 min.flame/fire rated finish required for NM cables to deal with.
 
MAC702 said:
So they will chew through the PVC coating on the MC anyway...



These really do work well. I've done so many offsets that it's quick and easy, but a friend bought one of these and I tried it on a job we did together. I was impressed.

31k5abbwu3L.jpg


It's a Greenlee Little Kicker.
Click to expand...

Yeah, my problem is not requiring a 1" offset while running, but rather I never make the second bend in the right place. :p
 
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