UL 1:2012 free download

UL 1:2012 free download Flexible Metal Conduit
1 Scope
1 .1 These requirements cover flexible aluminum and steel conduit designed for use as metal raceway for wires and cables in accordance with the National Electrical Code, NFPA 70.
2 Units of Measurement
2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information.
2.2 Unless otherwise indicated, all voltage and current values mentioned in this standard are root-mean-square (rms).
3 Undated References
3.1 .1 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard.
CONSTRUCTION
4 Strip Material
4.1 Steel
4.1 .1 The strip material used in flexible steel conduit shall be carbon steel, shall have a tensile strength of at least 34,000 lbf/in 2 (234.5 MPa) and shall be of uniform width and thickness throughout. All surfaces of the strip shall be free from scale and rust before application of the protective zinc coating specified in Section 1 0.
4.1 .2 Compliance of conduit with the surface-cleanliness requirement in 4.1 .1 is to be determined by visual inspection.
4.2 Aluminum
4.2.1 The strip from which flexible aluminum conduit is made shall have:
a) A tensile strength of at least 34,000 lbf/in 2 (234.5 MPa) and
b) A copper content of 0.40 percent or less.
The strip shall be of uniform width and thickness throughout.
5 Thickness of Strip
5.1 The thickness of the metal strip used for flexible metal conduit shall not be less than indicated in Table 5.1 for the specified conduit type.
Exception: The thickness of the metal strip may be less than indicated in Table 5.1 when the conduit complies with the requirements specified for extra reduced-wall flexible metal conduit (XRWFMC).
5.2 Compliance of conduit with the requirement in 5.1 is to be determined by measuring the strip before forming with a flat-nose machinist’s micrometer caliper calibrated to read directly to at least 0.001 inch or 0.01 mm. The thickness of a particular strip is to be determined as the average of five measurements.
6 Splices
6.1 Splices in steel and aluminum strip shall be made in a workmanlike manner and shall not materially increase the thickness or diameter of the conduit or lessen its mechanical strength.
6.2 Compliance of conduit with the requirement in 6.1 is to be determined by visual inspection.
7 Convolutions
7.1 Finished flexible steel and aluminum conduit shall have the number of convolutions per foot or the number of convolutions per 200 millimeters indicated in Table 7.1 .
8 Interior Surfaces
8.1 The interior surfaces of finished steel and aluminum conduit shall be free from burrs and sharp edges that can damage wiring.
8.2 Compliance of conduit with the requirement in 8.1 is to be determined by visual examination of the interior surfaces. A specimen of conduit approximately 1 ft (300 mm) in length is to be inspected by looking through it (first from one end then from the other) at an artificial light.