Questions: Question 12 1 pts How should metal parts of cord-and-plug-connected equipment be grounded, if grounding is required? They should be connected to a grounding-type attachment plug via an equipment grounding conductor. They should be grounded directly to the building's structural metal. They do not need to be connected to a grounding conductor if the equipment is doubleinsulated. They should be connected to a grounding-type attachment plug, but a grounding conductor is optional.

The answer is the first one: They should be connected to a grounding-type attachment plug via an equipment grounding conductor.

Explanation for each option:

1. They should be connected to a grounding-type attachment plug via an equipment grounding conductor.

   • This is the correct answer. When grounding is required, metal parts of cord-and-plug-connected equipment should be connected to a grounding-type attachment plug using an equipment grounding conductor. This ensures that any fault current is safely directed to the ground, reducing the risk of electric shock.

2. They should be grounded directly to the building's structural metal.

   • This is incorrect. While building structural metal can be part of a grounding system, the standard practice for cord-and-plug-connected equipment is to use a grounding-type attachment plug and an equipment grounding conductor.

3. They do not need to be connected to a grounding conductor if the equipment is double-insulated.

   • This is a true statement but not applicable to the question as it specifies "if grounding is required." Double-insulated equipment does not require grounding, but the question pertains to situations where grounding is necessary.

4. They should be connected to a grounding-type attachment plug, but a grounding conductor is optional.

   • This is incorrect. If grounding is required, the use of a grounding conductor is not optional; it is necessary to ensure safety.

In summary, the correct approach for grounding metal parts of cord-and-plug-connected equipment, when required, is to use a grounding-type attachment plug with an equipment grounding conductor.