Code Change Summary: A new section was added to require ground-fault protection of equipment (GFPE) for specific branch circuit disconnects.

GFPE has been required for many code cycles for feeder and service disconnects rated 1000 amps or more and installed on solidly grounded wye electrical systems of over 150 volts to ground, but not exceeding 600 volts phase-to phase. A common example is a 1000 amp, 480-volt feeder or service disconnect. This requirement is for the protection of the actual equipment, not personnel.

Always keep in mind that one trigger for the GFPE requirement is that the voltage TO GROUND is more than 150 volts. This rules out the typical 120/208 volt system where the voltage TO GROUND is 120 volts. In a 277/480 volt system, the voltage to ground is 277 volts.

On solidly grounded wye electrical systems, low level ground fault currents can be small enough to go unnoticed by the overcurrent device but yet large enough to damage the equipment over time. A disconnect with an integral GFPE device has protection for these small ground-fault conditions.

If a hazard exists for 1000-amp and larger feeder and service disconnects used on such systems, then the same hazard exists for the same size branch circuit disconnect, therefore the same requirement now appears in Article 210 for branch circuits.

For other than industrial applications, it is uncommon to see branch circuit disconnects rated 1000 amps or more.

Below is a preview of the NEC^®.  See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).