Steel Conduit and Electrical Metallic Tubing
Steel conduit and electrical metallic tubing (EMT)
refers to the steel-based durable enclosures that route individual
electrical wiring conductors in a building or structure and protect the
wires from impact, moisture, and chemical vapors.
are classified by wall thickness, mechanical stiffness, and material
used. Rigid metal conduit (RMC) is a thick-walled threaded tubing,
usually made of coated steel, stainless steel, or aluminum. Galvanized
rigid conduit (GRC) is galvanized steel tubing, with a tubing wall that
is thick enough to allow it to be threaded. Intermediate metal conduit
(IMC) is a thinner, lighter-weight version of RMC. Polyvinyl chloride
(PVC)–coated steel conduit is used for highly corrosive environments.
Related products include conduit and associated elbows, threaded
couplings, and nipples.
Since conduit must be installed in accordance with the National Electrical Code®
(NEC) and all applicable local regulations, Members develop proposals
for the NEC, International Code Council codes, and other codes.
- Develops, revises, and manages NEMA Standards,
technical bulletins, and user guides related to conduit and electrical
metallic tubing, and provides input on Underwriters Laboratories (UL)
Standards for steel conduit
- Participates in the American
National Standards Institute (ANSI) Accredited Standards Committee on
electrical rigid steel conduit, electrical metallic tubing, electrical
rigid aluminum conduit-aluminum, and intermediate metal conduit.
work of CANENA (Council for Harmonization of Electrotechnical Standards
of the Nations in the Americas) Technical Harmonization Subcommittee
NEMA Field Representative presentations on Grounding; Evaluation of
Steel Conduit and EMT as Equipment Grounding Conductors, Corrosion
Protection; and UL & NEC Requirements for Corrosion Protection of
RMC, IMC, EMT
- Direct encasement in concrete
- Electrical and communication outlet installation the middle of large open areas
- Protecting conductors against fire damage
- Protecting sophisticated control systems wiring
sensitive circuits from electromagnetic fields (EMF) and
electromagnetic interference (EMI), and preventing emission of such
interference from enclosed power cables
- Waterproof or submersible conduit system