What is the ampacity of each 3/0 AWG conductor in a 4-conductor, metal-clad cable supplying discharge lighting?

To determine the ampacity of each 3/0 AWG conductor in a 4-conductor, metal-clad cable supplying discharge lighting, it's important to reference the National Electrical Code (NEC) and consider the specific installation conditions.

The ampacity of a conductor depends on factors such as the conductor size, the type of insulation, the number of conductors in a cable, and the ambient temperature. For a 3/0 AWG copper conductor with a typical insulation type, the base ampacity in a standard environment is generally around 200 A. However, when considering a 4-conductor cable, adjustments must be made due to the potential for derating.

One factor is that as the number of conductors in a cable increases, the allowable ampacity for each conductor often decreases due to the cumulative heating effect when conductors run closely together. In this instance, a derating factor is applied because it is a 4-conductor configuration. Based on standard industry practices, applying the appropriate adjustment for a 4-conductor cable results in a reduced ampacity.

Typically, the final ampacity can be assessed in the context of the specific application for discharge lighting, which often falls within specific guidelines. After applying typical derating