GFCI protection for a feeder disconnect is required in which scenario?

GFCI protection for a feeder disconnect is required in which scenario?

• A. The feeder is rated 1,000 amps or more
• B. It is a solidly grounded wye system
• C. The system voltage is 480Y/277 volts
• D. All of these

Answer: (D)

Ground-fault protection of equipment is used on feeders to quickly detect and interrupt a ground fault, protecting both people and the equipment from damaging fault currents. When the wiring arrangement or size of the feeder creates a higher risk or higher energy fault, this protection is required at the feeder disconnect. If the feeder is rated at 1,000 amps or more, a ground fault can release a large amount of energy and pose serious hazards. Providing ground-fault protection here helps ensure the disconnect trips promptly and avoids equipment damage or fire. In a solidly grounded wye system, a ground fault can energize exposed parts and travel back through the system with little impedance. GFPE at the disconnect helps clear such faults quickly, reducing injury risk and equipment damage. On a 480Y/277 volt system, line-to-ground voltages are substantial, so a ground fault can be particularly dangerous. GFPE protection is required to detect these faults and trip the disconnect to protect personnel and equipment. Since any one of these scenarios warrants GFPE protection for a feeder disconnect, all of these conditions mean the protection is required.

Ground-fault protection of equipment is used on feeders to quickly detect and interrupt a ground fault, protecting both people and the equipment from damaging fault currents. When the wiring arrangement or size of the feeder creates a higher risk or higher energy fault, this protection is required at the feeder disconnect.

If the feeder is rated at 1,000 amps or more, a ground fault can release a large amount of energy and pose serious hazards. Providing ground-fault protection here helps ensure the disconnect trips promptly and avoids equipment damage or fire.

In a solidly grounded wye system, a ground fault can energize exposed parts and travel back through the system with little impedance. GFPE at the disconnect helps clear such faults quickly, reducing injury risk and equipment damage.

On a 480Y/277 volt system, line-to-ground voltages are substantial, so a ground fault can be particularly dangerous. GFPE protection is required to detect these faults and trip the disconnect to protect personnel and equipment.

Since any one of these scenarios warrants GFPE protection for a feeder disconnect, all of these conditions mean the protection is required.