Flexible Metal Conduit (FMC) and Liquidtight Flexible Metal Conduit (LFMC) are used in the construction of commercial and industrial properties around the world.
These products protect electrical wiring that provides current for power in commercial and industrial buildings.
The Flexible Metal Conduit Voting Classification is organized within the Building Wire and Cable Section. It concentrates on technical activities, including the development of application and installation guidelines and active involvement with Underwriters Laboratories Inc. and the National Electrical Code
Choose a link for more information on the FMC Voting Class:
Scope
All types of flexible metal conduit as identified in Article 348 of the National Electrical Code® (NEC®) and in compliance with UL 1/CSA C22.2 No. 56.
All types of liquidtight flexible metal conduit as identified in Article 350 of the National Electrical Code® (NEC®) and in compliance with UL 360/CSA C22.2 No. 56.
Technical Activities
In 2007, the FMC Voting Classification is engaged in the following activities:
1) Maintaining established positions on relevant changes proposed for the 2008 National Electrical Code.
2) Maintenance of NEMA application and installation guidelines for FMC and LFMC. Originally published in 2006, revisions will be considered in the fall based on changes to the national electrical Code for 2008.
3) Development and maintenance of NEMA Engineering Bulletins, which provide industry positions on specific product application or installation issues. NEMA Engineering Bulletin 93, published in 2006, clarifies the intent of NEC length limitations. Another Bulletin is being considered to address FMC used with equipment subjected to movement and vibration.
4) Interaction with Underwriters Laboratories Inc., in order to positively impact the UL 1 and UL 360 standards for safety. NEMA is currently working with UL toward a standardized program for evaluating new jacket materials for liquidtight flexible metal conduit.
5) Interaction with the outlet box and cable fittings industries. The FMC industry worked with the fittings industry to update NEMA FB 2.20, relevant to fittings for use with FMC and LFMC.
Relevant Standards and Publications:
NEMA standards and publications relevant to flexible metal conduit include:
NEMA RV 3-2006, Application and Installation Guidelines for Flexible and Liquidtight Flexible Metal Conduits
NEMA FB 1-2003, Fittings, Cast Metal Boxes, and Conduit Bodies for Conduit, Electrical Metallic Tubing, and Cable
NEMA FB 2.20-2003, Selection and Installation Guidelines For Fittings for Use With Flexible Electrical Conduit and Cable Status: Active
NEMA OS 1-2003, Sheet-Steel Outlet Boxes, Device Boxes, Covers, and Box Supports
NEMA OS 2-2003, Nonmetallic Outlet Boxes, Device Boxes, Covers, and Box Supports
NEMA OS 3-2002, Selection and Installation Guidelines for Electrical Outlet Boxes
NEMA Engineering Bulletin 93 (April 2006), Length Limitation for FMC and LFMC
Guidelines for Handling Water Damaged Electrical Equipment
UL standards relevant to flexible metal conduit include
UL 1, Flexible Metal Conduit
Click here for UL Guide Card information on Flexible Metal Conduit
UL 360, Liquidtight Flexible Metal Conduit
Click here for UL Guide Card information on Liquidtight Flexible Metal Conduit.
UL 467
Grounding and Bonding
UL 514B/CSA C22.2 No. 18.3/NMX-J-017-ANCE
Conduit, Tubing and Cable Fittings
(a trinational standard for North America)
Membership
Membership in NEMA is open to any firm actively engaged in the manufacture in North America of a product within the NEMA scope and for sale in the open market. Membership of foreign firms is subject to product section policies and NEMA Board of Governors approval.
NEMA operates on a fee-for-service basis. Each product section establishes its projects and activities and approves an annual operating budget. For more information on membership visit Joining NEMA.
