Article 350 Liquidtight Flexible Metal Conduit Type LFMC

I. General





This conduit is similar to flexible metal conduit, but it has a jacket over the metal conduit. The jacket is liquidtight, nonmetallic, and sunlight-resistant.


Listing Requirements


II. Installation


Uses Permitted

This conduit can be installed exposed or concealed, directly buried in earth and if protection from liquids, vapor, or solids is necessary or if flexibility is desired. It can be installed in hazardous areas if approved for that installation. Refer to Sections 501.4(B), 502.4, 503.3, 504.20, and 553.7(B).


Uses Not Permitted

It cannot be installed when subject to damage or where temperatures exceed that which is approved for the material.



Minimum metric designator 16 (trade size ½). For exceptions, refer to Section 348.20(A). The maximum size allowed is metric designator 103 (trade size 4). Refer to 300.1(C) for metric designators and trade sizes.


Number of Conductors or Cables

(A) Metric Designators 16 through 103 (Trade Sizes ½ through 4). Refer to Table 1, Chapter 9. Cables can be used if not prohibited by cable articles. Cables cannot exceed the fill requirements of Table 1, Chapter 9.

(B) Metric Designator 12 (Trade Size 3/8). Refer to the Fittings Outside Conduit columns in Table 348.22.


BendsHow Made

Bends must not damage the conduit and must not reduce the internal diameter of the conduit. Bends can be made with auxiliary equipment manually. The radius of the curve to the centerline can not be less than that shown in Table 2, Chapter 9. Use the "Other Bends" column.


BendsNumber in One Run

The maximum that is permitted is not more than 360° in bends between pull points.


Securing and Supporting

It must be supported and secured not more than 1.4 m (4½ ft.) apart. It must be securely fastened within 300 mm (12 in.) of a conduit termination. Four exceptions are for when the conduit is fished, where flexibility is needed, length not exceeding 900 mm (3 ft.) at terminals, lengths not exceeding 1.8 m (6 ft.) from a fixture terminal connection for tap conductors to a lighting fixture as noted in Section 410.67(C) and within accessible ceilings for lengths not exceeding 1.8 m (6 ft.) from the last point where the raceway is fastened, for connections to luminaires or other equipment. Horizontal runs allowed to be supported by the openings in framing members not more than 1.4 m (4½ ft.) apart and fastened within 300 mm (12 in.) of a termination.


Couplings and Connectors


Splices and Taps

They can be made only in accordance with Section 300.15.


Grounding and Bonding

This type of conduit can be used as a means of grounding under certain conditions. Refer to the NEC®.

III. Construction Specifications



Article 90 Introduction


Wiring and Protection

Wiring Methods and Materials

Equipment for General Use

Special Occupancies

Special Equipment

Special Conditions


Annex C. Conduit and Tubing Fill Tables for Conductors and Fixture Wires of the Same Size

Annex D. Examples

Annex E. Types of Construction

Pocket Guide to the National Electrical Code 2005
Pocket Guide to the National Electrical Code(R), 2005 Edition (8th Edition)
ISBN: 0131480014
EAN: 2147483647
Year: 2004
Pages: 120 © 2008-2020.
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