New York State Master Electrician Practice Exam

What grounding requirement applies to central vacuum outlet assemblies?

1. It must be double insulated

2. Accessible non-current-carrying metal parts must connect to a grounding conductor

3. It can be grounded at any point

4. There are no grounding requirements

The correct answer is: Accessible non-current-carrying metal parts must connect to a grounding conductor

The correct answer highlights an important safety measure regarding central vacuum outlet assemblies. According to the National Electrical Code (NEC) and typical electrical safety standards, accessible non-current-carrying metal parts must connect to a grounding conductor. This requirement ensures that any metal parts that might become energized due to a fault are properly grounded, minimizing the risk of electric shock to users. By grounding these accessible parts, the system provides a path for any fault current to safely travel to the ground. This grounding mechanism not only enhances user safety but also aids in preventing potential equipment damage or fire hazards that could result from stray electrical currents. The other choices present misunderstandings of grounding requirements. Insulating devices do not negate the need for grounding, as double insulation (the first choice) is not necessarily equivalent to proper grounding practices. Grounding must follow specific methods and locations, and it cannot simply be applied at any random point, as indicated in the third choice. Lastly, claiming that there are no grounding requirements ignores significant safety regulations that are commonly adopted in electrical installations. Thus, the requirement for connecting accessible non-current-carrying metal parts to a grounding conductor is fundamental for proper installation and safety.