Tennessee Wastewater Operator Practice Exam

In electrical wiring for business structures, what color is typically used for a ground wire?

1. Red

2. Black

3. Green

4. Blue

The correct answer is: Green

In electrical wiring, the color typically used for a ground wire is green. This standard applies to various electrical codes, including the National Electrical Code (NEC) in the United States. The ground wire is crucial as it provides a path for electrical current to return to the ground in case of a fault, thereby helping to prevent electric shock and ensure safety. Using green for ground wires helps to avoid confusion with other wires, as each color in electrical wiring serves a specific purpose. For instance, black is typically used for hot wires, while red can also indicate a hot wire or a second phase in a 240-volt system. Blue may be used for travelers in three-way switching applications or for other specific purposes depending on local codes. In summary, the use of green for ground wires is part of a systematic color-coding approach designed to enhance safety and clarity in electrical installations.