Quick, call a Plumber!

[problemsolver600]

:roll: My conduit just froze and burst!
I'm removing over 300' of 1/2" amd 3/4" EMT with set screw connectors from a ROOFTOP! In at least five locations the conduit was split open from water IN THE CONDUIT freezing up. Some one suggested that I reuse the wires in the rigid I am installing, but I pointed out that I can't tell which brown wire is which. Brown as in RUSTY brown.

Remember, motors run on smoke installed at the factory. If the smoke gets out, the motor won't run.

 

[haskindm]

Your new rigid conduit will probably freeze and burst eventually also unless you take steps to prevent it.
225.22 (2002) requires that conduits on exterior surfaces be "raintight and ARRANGED TO DRAIN". The reason for this is that these conduits will fill with water from CONDENSATION which must be drained or they will freeze and burst. The water you are finding probably has little to do with the set screw connectors, but rather from natural condensation. You will need to find a way to route the new conduit so that it may drain.

 

[don_resqcapt19]

I am somewhat surprised that the set screw couplings would not let the water leak out. Did it freeze and break at low points between couplings? Yes, rigid will do the same thing, so you must install it to drain,
Don

 

[mario]

:?: I didn't think that set screw connectors and couplings were allowed in wet locations in the first place ... I believe a "roof" would be considered "wet" ... I've seen them oked for concrete but don't think I've seen them oked for wet ... anybody ?? m

 

[haskindm]

I think I remember that not too long ago, UL removed the wet location listing from all EMT connectors. Before that time some set-screw connectors were listed for wet locations (I think, not quoting gospel here). Now only emt connectors that are a gold color are listed for wet locations. I believe that so far all of these are compression type connectors. Has anyone else heard this?

The following was copied from the UL website:

UL recently conducted a study to determine the reliability of "raintight" compression fittings to consistently comply with the wet location test criteria. Based on the results, UL initiated a more stringent follow-up test program to assure these products consistently exclude water to maintain their "raintight" marking.

As of March 2002, manufacturers of UL Listed "raintight" (wet location) compression type EMT fittings were required to comply with the more stringent follow-up test requirements. If they did not comply, they were no longer authorized to mark their UL Listed fittings with the "Raintight" marking.

Three manufacturers presently have Listing
As of July 2004, only three manufacturers are authorized to mark their Listed compression type EMT fittings with the "Raintight" marking.

Bridgeport Fittings Inc. has their 250 and 260 Series with an RT Suffix connectors and couplings in the 1/2, 3/4, and 1 inch trade size Listed for raintight applications.

These fittings are provided with additional sealing rings to exclude water. The installation instructions on the carton must be followed for proper installation. Look for the "Raintight" marking on the container and the UL Mark on the fitting.

O-Z/Gedney LLC has their Compression connectors, Cat Nos. 7050, 7075 and 7100, with a SR or SRT suffix and Compression couplings, Cat Nos. 6050, 6075 and 6100 with a SR suffix in the 1/2, 3/4, and 1 inch trade size Listed for raintight applications.

These fittings are provided with additional "O" rings and knock out gaskets to exclude water. The installation instructions on the carton must be followed for proper installation. Look for the "Raintight" marking on the container and the UL Mark on the fitting.

Steel City/Thomas & Betts, Inc. has their compression connectors Cat. Nos. TC-111A-RT and TC-711A-RT in the 1/2 trade size, TC-112A-RT and TC-712A-RT in the 3/4 trade size and TC-113A-RT and TC-713A-RT in the 1 in trade size. The installation instructions for all three trade size connectors state to "Tighten Gland nut until thread bottoms out." All the connectors employ a knockout gasket to exclude water.

Couplings Cat. Nos., TK-111A-RT in the 1/2 trade size, TK-112A-RT ? 3/4 trade size and TK-113A-RT in the 1 in. trade size. The installation instructions for the 3/4 trade size couplings specify to torque the compression nuts to 600 in-lbf and for the 1 trade size couplings specify to torque the compression nuts to 770 in-lbf.

These fittings are provided with solid compression rings (not split) to exclude water. The installation instructions in or on the carton must be followed for proper installation. Look for the "Raintight" marking on the container and the UL Mark on the fitting.

The availability of "raintight" fittings may change as manufacturers redesign their fittings to comply with UL's new follow-up "raintight" testing. It is imperative to always look for the proper marking on the product and container. If the product is not marked with the UL Listing Mark and the container is not marked "Raintight," then the fittings have not been Listed for raintight applications. As new "Raintight" Listings are promulgated, this page will be updated.

 

[don_resqcapt19]

I think the UL raintight listing is bogus....the old compression EMT fittings are at least as raintight as rigid conduit couplings.
Don

 

[brian wisemiller]

was the conduit not elevated above the surface of the roof with blocks of any kind?

 

[ramsy]

Next time, you might try low-point drainage using outdoor j-boxes w/ bottom holes. Drilling / open holes is not code, but maybe a necessary evil.

If that emt is frequently wet it could corrode in no time. PVC may be better.