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Flexible Metal Conduit

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 technical Committee is organized within the Building Wire and Cable Group and Dues Center.  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®. 

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 2012 the FMC Technical Committee is engaged in the following activities:

1) Development and review of Public Comments in response to Proposals for the 2014 National Electrical Code.

2) Publication of amendments to NEMA RV 3-2010, Application and Installation Guidelines for Flexible and Liquidtight Flexible Metal and Nonmetallic Conduits

3) 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 on a proposal to amend UL 360 to permit the conduit armor of LFMC to be other than steel.

4) Interaction with the outlet box and cable fittings industries, as needed.

Relevant Standards and Publications:

NEMA standards and publications relevant to flexible metal conduit include:

NEMA RV 3-2010, Application and Installation Guidelines for Flexible and Liquidtight Flexible Metal and Nonmetallic Conduits

NEMA FB 1-2007, Fittings, Cast Metal Boxes, and Conduit Bodies for Conduit, Electrical Metallic Tubing, and Cable

NEMA FB 2.20-2007, Selection and Installation Guidelines For Fittings for Use With Flexible Electrical Conduit and Cable

NEMA OS 1-2008 (R 2010), Sheet-Steel Outlet Boxes, Device Boxes, Covers, and Box Supports

NEMA OS 2-2008 (R 2010), Nonmetallic Outlet Boxes, Device Boxes, Covers, and Box Supports

NEMA OS 3-2007, Selection and Installation Guidelines for Electrical Outlet Boxes

NEMA Engineering Bulletin 93 (April 2006), Length Limitation for FMC and LFMC

NEMA Engineering Bulletin 100 (August 2010), Flexible Metal Conduit - National Recognized Testing Laboratories

Evaluating 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.

 
Manufacturers:

	AFC Cable Systems, Inc., a part of Atkore International
	Anamet Electrical, Inc.
	Electri-Flex Company
	International Metal Hose Company
	Southwire Company