UL 4:2021 pdf download.STANDARD FOR SAFETY-Armored Cable.
1.1 These requirements cover interlocked steel or aluminum armored cables that contain 2,3, or 4,14— 1 AWG insulated circuit conductors with or without grounding conductors and are for use as Type AC
Armored Cable in accordance with Article 320 and other applicable parts of the National Electrical Code (NEC), ANSI/NFPA 70.
1.2 These requirements cover cables for use at potentials of 600 V or less and at temperatures that are not higher than 75°C (167°F) for Type ACTH, or 90°C (194°F) for Types ACHH and ACTHH, depending upon the temperature rating of the insulated conductors used. Cables with aluminum armor are suitable only for use with connectors other than the direct-bearing set-screw type and only in alternating-current circuits.
2 References
2.1 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.
2.2 Wherever the designation” UL 1581” is used in this wire standard, reference is to be made to the
designated part(s) of the Reference Standard for Electrical Wires, Cables, and Flexible Cords (UL 1581).
2.3 Wherever the designation of “UL 2556” is used in this wire standard, reference is to be made to the
designated part(s) of the Standard for Wire and Cable Test Methods, UL 2556.
2.4 Wherever the designation to “UL 2885” is used in this wire standard, reference is to be made to the designated part(s) of the Outline of Investigation for Acid Gas, Acidity and Conductivity of Combusted Materials and Assessment of Halogens.
3 Units of Measurement
3.1 In addition to being stated in the inch/pound units that are customary in the USA, each of the requirements in this standard is also stated in units that make the requirement conveniently usable in countries employing the metric system (practical SI). Equivalent — although not necessarily exactly identical — results are to be expected from applying a requirement in USA or metric terms. Equipment calibrated in metric units is to be used when a requirement is applied in metric terms.
CONSTRUCTION
4 Materials
4.1 Each material used in an armored cable shall be compatible with all of the other materials used in the cable.
5 Conductors
5.1 General
5.1.1 Only copper, copper-clad aluminum, or an acceptable aluminum alloy shall be used for the conductors in a cable. Soft-annealed copper shall comply with the American Society for Testing and Materials Standard Specification for Soft or Annealed Copper Wire, ASTM B 3. Solid 12 — 8 AWG aluminum conductors shall comply with the requirements for aluminum-wire stock (aluminum-alloy conductor material). All aluminum conductors shall comply with the requirements for semi-annealed 8000 series conductors in Section 10 of UL 1581.UL 4 pdf download.