Combination MC connectors

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morepower

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OK, here's my first post. I have a contractor who has stripped about 40' of MC cable jacket and transitioned from MC to a rigid coupling to an emt connector to emt. The emt runs about 40'. Can anybody help me find a violation(s). I've checked with manufactures and have been told the reason they don't make such a fitting is due to the probability of the conductors getting damaged.
 
Re: Combination MC connectors

Unmarked conductors might be a problem,screw a coupling on the pipe use a threaded duplex mc connector,or a single if only one piece of mc
 
Re: Combination MC connectors

I'm not following the unmarked wires theory...
Why is it ok for unmarked wires to be in MC but not ok to be in conduit?

I don't think 330.40 would be violated by having an MC connector threaded into a female threaded fitting of the same type threads.
The whole thing sounds perfectly fine to me!

Sounds like he just didn't want to bend some pipe...or didn't know how to! :)

It's not a wet location is it?

[ November 09, 2005, 06:29 PM: Message edited by: davedottcom ]
 
Re: Combination MC connectors

I'm not ashamed to admit that I've done the same thing. At times, I didn't want to transition with a 4x4 and wirenuts just for a short run around an obscene obstacle, or at the end of a short run to terminate at equipement where flexibility was required.
 
Re: Combination MC connectors

I see nothing wrong with the connector-coupling-connector setup. However, there are commercially available ones form companies like OZ-Gedney.

IMO, there is a problem with using the un-marked conductors.
 
Re: Combination MC connectors

allenwayne, I think your statement actually identifies the problem. IMHO, it IS like NM, and just as in a recent lengthy thread which pointed out the conductors in NM aren't THWN, in a purely technical sense, I don't think we can identify the conductors in MC as approved for raceway installation as noted in 310(marked on surface, etc.)
We have all probaly done it, and it might be universally accepted, but, again IMHO, I beleive that technically its a violation.

[ November 09, 2005, 08:20 PM: Message edited by: augie47 ]
 
Re: Combination MC connectors

Thanks Hurk 27,

I tend to agree with Augie47.

His mistake may have been in the removal of the jacket.

330.10 (A) General uses Type MC cable shall be permitted as follows: There is a list of 12 uses , #7 reads "In any raceway"
Is it still MC when the M is removed? Nope .

Originally posted by augie47:

allenwayne, I think your statement actually identifies the problem. IMHO, it IS like NM, and just as in a recent lengthy thread which pointed out the conductors in NM aren't THWN, in a purely technical sense, I don't think we can identify the conductors in MC as approved for raceway installation as noted in 310(marked on surface, etc.)
We have all probaly done it, and it might be universally accepted, but, again IMHO, I beleive that technically its a violation.
Click to expand...
 
Re: Combination MC connectors

Thanks to all for the help. As you probably know by now, yes, I am an inspector, as well as an instructor. My main reason for finding fault was 110.3 ; I don't believe the fittings are approved for the application. Arlington fittings informed me that they don't make a transition fitting for mc to pipe because of the probability of damaging the conductors when the jacket is stripped for long lengths. I don't have my UL white book handy to look up the fittings. Thanks again.
 
Re: Combination MC connectors

"As long as the fitting is accessable after construction is compleated, It seems ok by the NEC.

See 300.15(F)"

From Hurk
I agree the 300.15(F) shows us that transitioning from one wiring method to another with the proper fitting is permitted. In using a threaded coupling to a fitting, makes this a little more difficult to decipher. I do not know if there is an MC to EMT fitting, so I cannot give a good answer - I will see if I can locate the proper info.
 
Re: Combination MC connectors

Some of the MC I have in the shop is marked the length, but orthers are not marked at all. So, could you use the marked cable and not the unmarked cable?
 
Re: Combination MC connectors

I know it's been a long time since I posted on this thread, but I wanted to thank everyone once again for their help. Thanks especially to hurk27; you nailed it for me. This project is being built per the '96 NEC. 300-15(b)of the '96 NEC is clear:"...A box shall be installed at the connection point between any such cable system and a raceway system..." The cable systems referred to include type MC.
 
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