Underground Service, Feeder, Branch Circuit, and Recreational Vehicle Site Feeder Circuit Conductors Article 551.80.Conductor Enclosures Adjacent to Motors over 1000 V Article 430.223.Used as Feeders and Services at Marinas and Boatyards Article 553.7(B).Permitted for Service Entrance wiring to six feet Article 230.43.Electric Signs and Outline Lighting over 1000 volts Articles 600.7/600.32(A)(1).Installed under raised floors in Data Processing Areas Articles 645.5 (E).
PVC: Rigid PVC is a plastic pipe similar in size to rigid metal conduit (RMC).This tubing is often called Smurf tubing for its blue color, though it also comes in gray and orange, depending on the manufacturer and/or use. Although the tubing is moisture-resistant and flame-retardant, it's not suitable to exposed locations and should not be installed outdoors or anywhere that may be exposed to the elements. Electrical Non-Metallic Tubing (ENT): Electrical nonmetallic tubing is flexible plastic tubing designed for use inside residential walls or concrete block structures.IMT has largely replaced RMC in new construction, and both RMC and IMC are joined with threaded connections. They are used for the structural piping that houses the wiring for the home's connection to the utility service lines for many overhead services. Rigid Metal Conduit (RMC) and Intermediate Metal Conduit (IMC): Rigid metal conduit and intermediate metal conduit are heavy-duty conduits made of galvanized steel.
It has unique connectors and is used when less protection is needed for the conduit, as in indoor settlings. Non-Metallic Liquid-tight Flexible Conduit: Non-metallic liquid-tight conduit is often used in place of liquid-tight flexible metal conduit (LFMC).It is used for outdoor wiring serving air conditioning units and other outdoor equipment. Its close cousin, liquid-tight flexible metal conduit, is a flexible metal conduit covered with plastic sheathing to make it watertight. FMT tubing is commonly used for short runs in exposed locations, such as wiring for garbage disposers and water heaters. Flexible Metal Conduit (FMT) and Liquid-tight Flexible Metal Conduit (LFMC): Flexible metal conduit has a spiral construction which allows the conduit to bend easily, simplifying installation in walls or other structures.Outdoors, EMT will typically last a few years-indoors, it'll last indefinitely. EMT is best used indoors for residential and light commercial construction-if it's installed outdoors, it needs to be assembled along with watertight fittings. EMT is technically tubing, not conduit, hence the abbreviation uses the letter "T" instead of "C." Because the tubing is thin and lightweight, it is easy to bend with a special tool called a conduit bender. Electrical Metallic Conduit (EMT): Electrical metallic conduit is a rigid, thin-walled metal conduit typically made of galvanized steel.The Spruce Home Improvement Review Board.