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#61505 - 01/26/06 02:42 PM Compression Couplings
master66 Offline
Registered: 04/18/02
Posts: 257
Loc: Masontown, PA, USA
Is there any time that it is MANDATORY (required by NEC)to use compression coulpings as opposed to set screw on EMT conduit?

I am running a 4" EMT conduit through a store to feed a store next to it and I started wondering...
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#61506 - 01/26/06 02:50 PM Re: Compression Couplings
bot540 Offline
Registered: 09/14/04
Posts: 174
Loc: Vernon Hills, IL
I don't believe the nec even mentions compression or set screw connectors. They're both listed. I could be wrong.
Your installation isn't in violation of 230.3, is it?
Jesus may have been a capenter,but God was an electrician.Genesis1:3
#61507 - 01/26/06 02:50 PM Re: Compression Couplings
Dnkldorf Offline
Registered: 12/12/04
Posts: 1064
Loc: nowhere usa
I changed my answer from outside, to no.


[This message has been edited by Dnkldorf (edited 01-26-2006).]
#61508 - 01/26/06 04:32 PM Re: Compression Couplings
e57 Offline
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
358.42 Couplings and Connectors.
Couplings and connectors used with EMT shall be made up tight. Where buried in masonry or concrete, they shall be concretetight type. Where installed in wet locations, they shall be of the raintight type.

Fittings have been tested for use only with steel EMT unless there is specific marking on the device or carton to indicate the fittings are suitable for use with aluminum or other material.
According to 358.6, only listed fittings are permitted to be used with EMT. According to UL 797, Electrical Metallic Tubing, listed fittings that are suitable for use in poured concrete or where exposed to rain are so indicated on the fitting or carton. The term raintight or the equivalent on the carton indicates suitability for use where directly exposed to rain. The term concretetight or equivalent on the carton indicates suitability for use in poured concrete. See 225.22 and 230.54(A) for raintight requirements as applied to raceways on exterior surfaces of buildings and to service raceways.
Indentor-type fittings are for use with metallic-coated electrical metallic tubing only and require a special tool supplied by the manufacturer for proper installation. Diametrically opposed indentor-type tools require two sets of indentations nominally 90 degrees apart. Triple-indent tools require one set of indentations.

This is the only NEC listing requirements for Rain-tight, and Concrete-tight. Most of which are compression styled. Unless you are otherwise required by ammendment by local AHJ, or job spec's?
Mark Heller
"Well - I oughta....." -Jackie Gleason
#61509 - 01/26/06 06:42 PM Re: Compression Couplings
master66 Offline
Registered: 04/18/02
Posts: 257
Loc: Masontown, PA, USA
No. Not in violation of 230.3. There is going to be a 2 gang meter socket / disconnect on the outside of the building. Each of the two tennant spaces will be subfed from the meter socket.

Thanks for the replies guys.

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