NEC Commercial Electrical Practice Test

For conductor insulation color used in switch loops, which color should be utilized for the grounded circuit conductor?

1. Blue

2. White or Gray

3. Red

4. Green

The correct answer is: White or Gray

In a switch loop, the grounded circuit conductor is typically identified by the use of white or gray insulation. This follows the National Electrical Code (NEC) guidelines, which standardize color codes to promote safety and consistency in electrical installations. The white or gray insulation indicates that this conductor is meant to be the grounded conductor, which is crucial in preventing electrical shock hazards and ensuring proper circuit operation. This conductor serves as the return path for current, and its standardization helps electricians quickly and accurately identify its function within the circuit. Other colors such as blue, red, or green are reserved for different purposes: blue and red commonly signify hot conductors, while green is designated for grounding conductors. Therefore, utilizing white or gray for the grounded circuit conductor in switch loops aligns with NEC standards and reinforces safe electrical practices.