Double Barrel MC connectors

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Sloppy

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We ran out of single barrel MC connectors on a job but had plenty of snap-in double barrels. Would it be a code violation to use doubles for a single MC cable entering a box?
 
It would depend on the listing of the connector if it could be used for a single cable.

Welcome to the forum. :)
 
Thank you. I'm not sure of what the indication is on the listing, It's an arlington 3838AST. I'm kind of at a loss as to where/how to find if it's suitable. Are we talking about contacting UL or CSA?
 
Sloppy said:
Thank you. I'm not sure of what the indication is on the listing, It's an arlington 3838AST. I'm kind of at a loss as to where/how to find if it's suitable. Are we talking about contacting UL or CSA?
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The issue that I see is that with only one cable the other opening in the connector remains open. Now if he connector is listed for use with either one or two cables then my concern is moot.
 
I've got several cases of those. 15 boxes I bought at an auction. Practically free. I've never known the answer to the ops question either. They sure look weird with just one cable in it.
Mine have a tab that goes across the opening. That holds the cable in when pushed. But It's not entirely closed. I'm sure bugs could get in.
 
hillbilly1 said:
I hate the double barrels, especially with 277. I’ve had to go behind too many people that skin the wires up stuffing two cables into the connector!
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I would say it's installer error. If you are talking specifically about the 3838asts, I really don't see that the double barrel is more likely to knick the insulation than the single 38ast. On either one you need to carefully guide the conductors in and make a little bend at the very end to push it away from the spikes.
 
electrofelon said:
I would say it's installer error. If you are talking specifically about the 3838asts, I really don't see that the double barrel is more likely to knick the insulation than the single 38ast. On either one you need to carefully guide the conductors in and make a little bend at the very end to push it away from the spikes.
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Exactly, but “carefully” isn’t in their vocabulary! LOL!
 
Sloppy said:
We ran out of single barrel MC connectors on a job but had plenty of snap-in double barrels. Would it be a code violation to use doubles for a single MC cable entering a box?
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I think with only on cable in it would be the equivalent of leaving an open KO in the box, a code violation.
 
I wouldn’t be worried as much about fingers getting in it as I would dust and insects.

What type of installation is this commercial , resi ?
 
infinity said:
The issue that I see is that with only one cable the other opening in the connector remains open. Now if he connector is listed for use with either one or two cables then my concern is moot.
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So why couldn't one stick in a short length of cable but not terminate any conductors? No different than a "for future use" cable being inserted.
 
electrofelon said:
I would say it's installer error. If you are talking specifically about the 3838asts, I really don't see that the double barrel is more likely to knick the insulation than the single 38ast. On either one you need to carefully guide the conductors in and make a little bend at the very end to push it away from the spikes.
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single port connectors can slice conductors as well, maybe not quite as easily but they can.
 
hillbilly1 said:
I hate the double barrels, especially with 277. I’ve had to go behind too many people that skin the wires up stuffing two cables into the connector!
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I don't have an issue with double barrel/ duplex connectors in general but stay away from two 12/3 mc's especially with 277/ 480 volt.
I don't have a problem with stuffing one in on one side you could always stick a dummy piece on the other side to balance it out if it sits better that way.
 
Dsg319 said:
I wouldn’t be worried as much about fingers getting in it as I would dust and insects.

What type of installation is this commercial , resi ?
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Many loadcenter cabinets have some significant holes in them already. Take any the current QO or Homeline panels and mount them between studs instead of on a surface and the mounting holes in the back are plenty large for insects maybe even small reptiles to enter. I find myself caulking them shut because of this quite often when not surface mounted.

Had a mouse get into a Siemens disconnect and chewed off conductor insulation and eventually led to faults and blowing fuses a couple years ago at irrigation equipment site. The equipment was mounted on boards between two posts, board rotted around top mounting hole and top of disconnect leaned forward, that keyhole slot for mounting was large enough for the mouse to get in, but gap is too small when actually tight to the surface.
 
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