UL 1277:2021 PDF Download

UL 1277:2021 is a standard that outlines the requirements for electrical power and control tray cables with optional optical-fiber members. These cables can consist of either two or more current-carrying circuit conductors made of copper, aluminum, or copper-clad aluminum, or one or more pairs of thermocouple-extension wires. It is important to note that thermocouple-extension wires and circuit conductors cannot be mixed within the same cable.

The cables covered by this standard can be constructed with or without grounding conductors and individually jacketed optical-fiber members, all under an overall jacket. They are intended for use in cable trays, raceways, and outdoor locations with appropriate support by a messenger wire, in accordance with the National Electrical Code (NEC) and other applicable regulations.

The conductors used in these cables are described in the standard, including NEC types and other conductor types. The cables are surface marked to indicate the type of conductor, temperature ratings, and whether they are suitable for direct burial or sunlight exposure. They may also include optical-fiber members, which are marked accordingly. Additionally, the cables may have jackets that are oil resistant and are marked accordingly.

It is important to note that these cables have an overall jacket that is considered a "gas/vapor-tight continuous sheath." However, the standard does not cover the investigation of these cables for transmission of gases or vapors through the core. Therefore, if these cables are used in a hazardous location, additional sealing may be required as per NEC requirements.

These cables may contain one or more metal shields but do not have a metal sheath or armor. Cables with metal sheaths or armor are covered under a different standard. The connectors and fittings used with these cables are covered by the Standard for Conduit, Tubing, and Cable Fittings.

Lastly, it is important to note that this standard does not cover the optical or other performance aspects of the optical-fiber members or groups of such members.