QUINCY, Massachusetts — The National Fire Protection Association (NFPA) is accepting public comments on a proposed extension of the National Electrical Code (NEC) exception for ground-fault circuit-interrupter (GFCI) protection on listed outdoor HVAC equipment.

AHRI submitted three Tentative Interim Amendments (TIAs), combined as TIA Log No. 1924, that would extend Exception No. 2 to NEC 210.8(F) through Septe. 1, 2028. The proposed changes apply to the 2020, 2023, and 2026 editions of the NEC.

The current HVAC equipment exception expires Sept. 1, 2026. Public comments on the proposed extension are due Sept. 9. The NFPA Standards Council will then review the comments and determine whether to issue the TIA.

ACCA submitted comments supporting AHRI’s proposal. 

“This is not a choice between electrical safety and equipment reliability,” said David Bixby, ACCA manager of codes. “The record shows that unintended loss of air conditioning during extreme heat can itself create a serious life-safety risk. The responsible course is to allow the technical work to be completed while preserving a finite path toward the ultimate GFCI solution.”

ACCA’s comments point to unresolved technical issues identified by an NFPA Standards Council GFCI task group in 2022. The group identified nuisance-tripping experiences involving both single-stage and variable-speed HVAC equipment. It also concluded that the causes of the nuisance tripping remained unknown and required additional study.

Testing cited in AHRI’s TIA substantiation also raised compatibility concerns. According to the filing, 5 of 12 GFCIs tested tripped below the applicable must-hold current above 60 Hz.

ACCA said the availability of high-frequency GFCIs represents progress but does not demonstrate compatibility across the installed population of listed HVAC equipment, particularly conventional 60-Hz single-stage systems.

The association also cited potential life-safety concerns associated with unintended cooling loss. ACCA referenced the Maricopa County Department of Public Health’s 2024 Heat-Related Deaths Report, which recorded 138 indoor heat-related deaths. Air conditioning was present in 88% of those cases. Among cases where air conditioning was present, the unit was not functioning in 70% and was not in use in another 18%.

ACCA said some occupants, including people aging in place, convalescing, or experiencing physical or cognitive impairments, may be unable to recognize a loss of cooling, reset a GFCI device, or arrange immediate repairs.

The proposed extension would not eliminate GFCI protection requirements. ACCA said it would provide additional time for contractors, manufacturers, testing laboratories, standards developers, AHRI, and GFCI manufacturers to complete testing and field validation.

Stakeholders can submit public comments to NFPA by email at [email protected]. Comments should include “NFPA 70 Proposed TIA 1924” in the subject line.