The National Electrical Manufacturers Association has published NEMA RV 3 Application and Installation Guidelines for Flexible Metal and Liquidtight Flexible Metal and Nonmetallic Conduit.
Last published in 2012, this version of NEMA RV 3 includes:
- addition of conduit armor metals other than galvanized steel, recognized in UL 360
- addition of application information regarding braiding material and the possible need for a bonding strip
- addition of new markings for conduit armor metals other than galvanized steel, recognized in UL 360
- clarifications to the formula for calculating overall length of conduit installed in a vertical loop with offset
- clarifications to figure 2 illustrating overall lengths for lateral offset installations, and associated tables
Developed by the NEMA 7WC-1 Section, this standard provides installers and inspectors with an industry perspective of best practices in the use and installation of flexible metal and liquidtight flexible metal and nonmetallic conduits that NEMA members manufacture. Focus is placed on important fundamentals and recent changes to codes, product standards and installation practices. This is of particular interest for industries that work with flexible metal conduit and liquidtight flexible metal conduit fittings, outlet boxes, electrical enclosures, and renewable energy, as well as electrical contractors, electrical inspectors, and product purchasers.
NEMA RV 3-2014 may be downloaded at no charge or purchased in hard copy for $96 on the NEMA website.