Thread Sealant

[mtech]

I have questions on the use of thread sealant on conduit fittings. Is it acceptable as long as the conduit is not used as the ground conductor?

 

[jamesoftn]

NEC 2008 250.12 250.12 Clean Surfaces. Nonconductive coatings (such as
paint, lacquer, and enamel) on equipment to be grounded
shall be removed from threads and other contact surfaces
to ensure good electrical continuity or be connected by
means of fittings designed so as to make such removal
unnecessary. I believe this answers the question.

 

[M. D.]

I have questions on the use of thread sealant on conduit fittings. Is it acceptable as long as the conduit is not used as the ground conductor?

The conduit has to provide a fault current path so you would have to use a listed or otherwise approved compound.

http://www.steelconduit.org/pdf/ConGuide.pdf

Steel conduit is the main equipment grounding conductor
regardless of whether a supplemental equipment
grounding conductor is installed. In the event of a
fault, the raceway will carry most of the current and
therefore must be continuous. For this reason, each
raceway must be installed securely and with tight
joints to provide mechanical and electrical continuity.

4.1.3 Protection of field cut threads
NEC Section 300.6 (A) requires that where corrosion
protection is necessary and the conduit is threaded in
the field, the thread shall be coated with an approved
electrically-conductive, corrosion resistant compound
(see Figure 20). Coatings for this purpose, listed
under UL category ?FOIZ? are available. Zinc-rich
paint or other coatings acceptable to the AHJ may be
used.