At the time of installation, grounded conductors of what gauge or larger can be identified by distinctive markings?

The identification of grounded conductors by distinctive markings is a requirement established in the National Electrical Code (NEC) to ensure clarity and safety during installation and maintenance. Grounded conductors, which are typically either neutral conductors or conductors that are intentionally grounded, must be distinguishable to help electrical professionals identify them easily.

In this context, the correct gauge for which grounded conductors can be identified by distinctive markings is 4 AWG and larger. This means that conductors of 4 AWG, 2 AWG, and larger are required to have specific markings to enhance safety and prevent accidental errors in connections or repairs. This requirement allows for easy recognition and is particularly important in complex electrical systems where many different conductors may be present.

Choosing a smaller gauge like 6 AWG or 8 AWG does not meet the marking requirement since these gauges do not need to have distinctive markings, which can lead to confusion during electrical work. By establishing this marking requirement from 4 AWG and above, the NEC aims to improve safety standards in electrical installations.