Code Change Summary: Section 410.184 was revised and reformatted into a list structure with expanded provisions clarifying GFCI and SPGFCI protection requirements for horticultural lighting equipment.

SME commentary: The 2026 NEC^® reorganizes and expands Section 410.184 to enhance clarity for installers, designers, and enforcement officials. The revision breaks the previous single paragraph into a two-part list format that distinguishes requirements based on voltage to ground, with new detailed provisions for both Class A GFCI protection and Special Purpose Ground-Fault Circuit Interrupter (SPGFCI) protection.

Under the 2023 NEC^®, Section 410.184 required lighting equipment identified for horticultural use and employing flexible cords or separable connectors to be supplied by outlets protected by a listed GFCI. An exception required circuits exceeding 150 volts to ground to instead use SPGFCI protection. The 2026 revision removes the exception format, and integrates the language into positive enforceable text, now appearing as 410.184(A) and 410.184(B). This new structure clarifies that branch circuits rated 150 volts or less to ground, whether single-phase or three-phase, must be protected by a listed Class A GFCI. For single-phase or three-phase branch circuits exceeding 150 volts to ground, protection must be provided by a listed SPGFCI with a ground-fault trip current not exceeding 20 mA. SPGFCI protective equipment listed solely for use with protected equipment employing a double insulation system shall not be used for this purpose.

Horticultural lighting systems often utilize high-intensity discharge (HID) or specialized LED fixtures that operate at higher voltages than conventional residential luminaires. Some are supplied by flexible cords with separable cord connectors or attachment plugs to allow daisy chaining, tilting, relocating, or repositioning of the light source for optimal plant growth. These configurations present increased exposure to shock hazards over hard-wired installations, making GFCI protection essential. The distinction between Class A GFCI and SPGFCI in this section aligns with the scope of UL 943 and UL 943C, recognizing that traditional Class A GFCI protection is not always feasible for horticultural lighting equipment supplied at voltages beyond the limits of a Class A device. In such cases, SPGFCI protection provides a level of shock protection where higher voltage systems are used in accordance with the Code.

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 2026 NEC^® edition of NFPA 70.

2023 Code Language:

410.184 Ground-Fault Circuit-Interrupter (GFCI) Protection and Special Purpose Ground-Fault Circuit-Interrupter (SPGFCI) Protection. Lighting equipment identified for horticultural use and employing flexible cord(s) with one or more separable connector(s) or attachment plug(s) shall be supplied by lighting outlets protected by a listed GFCI.

Exception: Circuits exceeding 150 volts to ground shall be protected by a listed SPGFCI.

2026 Code Language:

410.184 Ground-Fault Circuit-Interrupter (GFCI) Protection and Special Purpose Ground-Fault Circuit-Interrupter (SPGFCI) Protection. Lighting equipment identified for horticultural use and employing flexible cords with one or more separable connectors or attachment plugs shall be supplied by lighting outlets protected in accordance with 410.184(A) or 410.184(B).

(A) For Circuits Not Exceeding 150 Volts or Less to Ground. Branch circuits rated 150 volts or less to ground, single- or 3-phase, shall be provided with a listed Class A GFCI.

(B) For Circuits Exceeding 150 Volts to Ground. Branch circuits rated above 150 volts to ground, single- or 3-phase, shall be provided with a listed SPGFCI with a ground-fault trip current not exceeding 20 mA. SPGFCI protective equipment that is listed only for use with protected equipment that employs a double insulation system shall not be used for this purpose.