True or false: A disconnecting means is required for all ungrounded conductors if they supply or pass through a building.

True or false: A disconnecting means is required for all ungrounded conductors if they supply or pass through a building.

• A. True
• B. False
• C. Only for feeders
• D. Only for service conductors

Answer: (A)

The important idea here is that you must be able to shut off power to a building safely. When ungrounded conductors supply or pass through a structure, a readily accessible disconnecting means is required at or near where those conductors enter the building. This ensures that, for maintenance or emergencies, the entire building’s power can be de-energized from a safe location, protecting workers and occupants. This applies to both service conductors and feeders that terminate or pass through the building, not just one type. Since ungrounded conductors carry the current, having a disconnect available for them at the building boundary is the essential safety feature.

The important idea here is that you must be able to shut off power to a building safely. When ungrounded conductors supply or pass through a structure, a readily accessible disconnecting means is required at or near where those conductors enter the building. This ensures that, for maintenance or emergencies, the entire building’s power can be de-energized from a safe location, protecting workers and occupants.

This applies to both service conductors and feeders that terminate or pass through the building, not just one type. Since ungrounded conductors carry the current, having a disconnect available for them at the building boundary is the essential safety feature.