Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsEasy
A maintenance technician is replacing a flexible cord on a portable industrial machine operating at 480 volts. The original cord had a green insulated conductor. What is the NEC-mandated color for the equipment grounding conductor in a flexible cord?
- AWhite or gray
- BGreen or green with yellow stripes
- CBlack or red
- DBlue or yellow
Show answer & explanationAnswer & explanation
Correct answer: B. Green or green with yellow stripes
NEC 400.22(B) specifies that the equipment grounding conductor in a flexible cord must be identified by a continuous outer finish that is either green or green with one or more yellow stripes.
Why the other options are wrong
- A. Incorrect. White or gray are reserved for grounded (neutral) conductors.
- C. Incorrect. Black, red, blue, etc., are typically used for ungrounded (hot) phase conductors.
- D. Incorrect. Blue or yellow are typically used for ungrounded (hot) phase conductors.
Flexible Cord Grounding Color
The equipment grounding conductor in flexible cords and cables must be uniquely identified by a green or green with yellow stripes insulation to prevent misidentification and ensure safety.
- NEC 400.22(B) mandates the color coding for flexible cord conductors.
- Green is reserved exclusively for grounding conductors.
- Proper color identification is critical to prevent shock hazards.
Memory trick: Green means ground, safe and sound!