HOLT Electricians Practice Exam

For permanently connected appliances rated over what voltage or horsepower, can the branch circuit switch serve as the disconnecting means?

1. 100 volts

2. 250 volts

3. 300 volts

4. 400 volts

The correct answer is: 300 volts

The branch circuit switch can serve as the disconnecting means for permanently connected appliances rated over 300 volts. This is based on the National Electrical Code (NEC), which specifies that certain conditions must be met when dealing with high-voltage appliances. For branch circuit switches to effectively function as disconnecting means, they must be able to completely disconnect the power to the equipment, ensuring safety during maintenance and servicing. The threshold of 300 volts is significant because it is a clear delineation point for equipment that may require more stringent safety protocols due to the increased hazards associated with higher voltage levels. While other voltage ratings provided in the choices might pertain to different applications or types of equipment, only appliances over 300 volts fall under the specific guideline that allows for the branch circuit switch to act as the disconnecting means according to safety standards and the NEC. This ensures that electricians and maintenance personnel can safely manage and work on these higher voltage systems.