Code Change Summary: A new definition of a Special Purpose Ground-Fault Circuit Interrupter has been added to Article 100.

Article 100 defines the typical Class A Ground-Fault Circuit Interrupter (GFCI) as intended for personnel protection. These devices are designed to trip when current leakage to ground is in the range of 4mA to 6mA. Article 100 also defines Ground-Fault Protection of Equipment (GFPE) for equipment protection which is designed to trip in the 30 mA or higher range, and therefore is not typically selected for personnel protection.

In the 2023 NEC^®, Article 100 now defines Special Purpose Ground-Fault Circuit Interrupters (SPGFCI) since changes made in Section 410.184 and Article 680 now specify the use of these devices.

An SPGFCI is a device used in circuits with voltage to ground greater than 150 volts that detects ground-fault currents, and functions to de-energize a circuit or portion of a circuit within an established period of time when a ground-fault current is detected that exceeds the values established for Class C, D, or E devices.

SPGFCI devices trip at higher levels of current leakage than a Class A device, but at lower levels than a GFPE device; typically, between 15mA and 20mA.

Since the thresholds for the current that the SPGFCI responds to could be below ventricular fibrillation thresholds, but not below human let-go thresholds, the phrase "personnel protection" was intentionally left out of this new definition.

Class A GFCIs are rated for voltages not greater than 150 volts to ground, which is why they cannot provide the protection required for horticultural lighting outlets specified in the exception to Section 410.184 or pool pump motors supplied by circuits operating at higher voltages to ground, which often exist in commercial pool environments and water parks.

For these installations, the NEC^® will now require the use of SPGFCI devices.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC^® edition of NFPA 70.