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#96761 - 12/24/05 01:58 PM MC in wet locations  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,076
Estero,Fl,usa
Most MC I see is listed "wet location" but do they make a wet location connector?
How do you keep the water out of the box?


Greg Fretwell

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#96762 - 12/24/05 02:40 PM Re: MC in wet locations  
George Little  Offline
Member
Joined: Jan 2004
Posts: 1,489
Michigan USA
Can't keep it out. Best advice I'd give would be to provide a drain hole. Something like we have for signs. See 600.9(D) for size for signs. Probably wouldn't need to be that large diameter for boxes but the concept is the same. If one installs the MC cable with a drip loop this would help. Also look at 225.22 and Exception. Interesting.


George Little

#96763 - 12/24/05 03:01 PM Re: MC in wet locations  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
The only MC I have installed in wet locations is what we call 'parking deck cable' which is jacketed MC. There area WP connectors for it.

As for standard MC I think George is onto it.

Quote
348.12 Uses Not Permitted.
FMC shall not be used in the following:
(1) In wet locations unless the conductors are approved for the specific conditions and the installation is such that liquid is not likely to enter raceways or enclosures to which the conduit is connected


It goes without saying MC is not FMC but I think we could apply the same logic.


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#96764 - 12/25/05 02:48 AM Re: MC in wet locations  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,076
Estero,Fl,usa
There just seems to be a disconnect between the people who insist that EMT connectors are raintight and the guy who thinks MC or FMC is OK.


Greg Fretwell

#96765 - 12/25/05 01:01 PM Re: MC in wet locations  
renosteinke  Offline
Cat Servant
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Joined: Jan 2005
Posts: 5,316
Blue Collar Country
I was also surprised to learn that MC is approved for wet locations; all the connectors I've seen are marked "dry only."
I also note that a similar product- AC - is NOT approved for wet locations.

I am guessing that the insulated full-size groound, and the plastic (rather than paper) wrap of the wires are the reasons for this approval.

I am also guessing that the intent is to allow MC to pass through a wet location, without requiring a change in wiring methods.


#96766 - 12/26/05 12:03 PM Re: MC in wet locations  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Quote
There just seems to be a disconnect between the people who insist that EMT connectors are rain tight and the guy who thinks MC or FMC is OK.


Good point. [Linked Image]


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#96767 - 01/01/06 04:02 PM Re: MC in wet locations  
tdhorne  Offline
Member
Joined: Mar 2001
Posts: 345
Maryland, USA
Quote
There just seems to be a disconnect between the people who insist that EMT connectors are rain tight and the guy who thinks MC or FMC is OK.
Did you mean to say
Quote
There just seems to be a disconnect between the people who insist that EMT connectors should be listed as rain tight and the guy who thinks MC or FMC is OK.

--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison


Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison

#96768 - 01/02/06 12:11 AM Re: MC in wet locations  
BobH  Offline
Member
Joined: Oct 2004
Posts: 135
Newfane, N.Y USA
I've seen it strung from a house to a garage and I thought for sure this was a violation when I first saw it, then I checked its listing, I was wrong. It's raintight and I can see a few scenarios where this would be very convenient.


#96769 - 01/02/06 02:17 PM Re: MC in wet locations  
elektrikguy  Offline
Member
Joined: May 2002
Posts: 132
woodstock,ga,usa
Interesting timing on this thread....I just finished wiring an exhaust fan for a dishwasher in a commercial kitchen. It was the type with the 1/2 inch tube for the wire to drop through and was roof mounted. The duct guy promptly told me that I needed to install sealtite and a pitch box. He said he has never seen MC used in his career I peeled back the aluminum armor and exposed the THHN-THWN conductors to him.


#96770 - 01/02/06 03:06 PM Re: MC in wet locations  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
We always use MC for that application. [Linked Image]


Bob Badger
Construction & Maintenance Electrician
Massachusetts


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