NEC Commercial Electrical Practice Test

Which color marking is used for the identification of grounded conductors in multi-conductor cables during installation?

1. Black

2. Red

3. White

4. Green

The correct answer is: White

In electrical installations, the color marking for grounded conductors is essential for safety and proper identification. The National Electrical Code (NEC) specifies that grounded conductors should be identified by white or gray insulation. This requirement applies to both individual conductors and the conductors within multi-conductor cables. Using white or gray for grounded conductors helps ensure that any electrical professional can quickly identify these conductors during installation, maintenance, or troubleshooting, which is crucial for preventing accidental contact with live parts and ensuring the integrity of the grounding system. Recognizing the correct color helps maintain consistency across the industry, minimizing confusion and enhancing safety in electrical work. Other colors, such as black, red, or green, have specific designations for either ungrounded conductors or equipment grounding conductors, which serves different purposes and cannot be used interchangeably. This clarity in marking is vital for compliance with the NEC and overall electrical safety.