UL 493:2021 PDF Download

The UL 493:2021 standard covers various types of cables used for underground feeder and branch circuits. Specifically, it includes 14 - 4/0 AWG single-conductor PVC-insulated and -jacketed cables, as well as flat multiple-conductor PVC-jacketed cables containing two or three 14 - 6 AWG PVC-insulated circuit conductors, with or without an equipment grounding conductor. These cables are intended for use in wiring systems operating at 600 V or less, in accordance with Article 340 and relevant parts of the National Electrical Code, ANSI/NFPA 70.

The standard distinguishes between different cable types based on their markings. Multiple-conductor cables marked as "UF-B" have a 75°C jacket and conductors insulated for 90°C dry and at least 60°C wet locations. Multiple-conductor cables marked as "UF" have a 60°C jacket and conductors insulated for 60°C dry and wet locations. Single-conductor cables marked as "UF" have integral insulation and jacket for 60°C dry and wet locations. The ampacity of all cables covered in the standard is based on 60°C conductors.

However, the standard does not cover insulation materials other than PVC. It also excludes round cables with two or more circuit conductors, flat cables with more than three circuit conductors, and multiple-conductor cables with circuit conductors larger than 6 AWG. These specific exclusion criteria are not within the scope of UL 493:2021.