AHRI’s bid to delay GFCI rule for outdoor HVAC equipment heads to public comment

A long-running exception to the National Electrical Code (NEC) that exempts outdoor HVAC equipment from GFCI protection is set to expire on September 1. 

But AHRI has pushed to extend that deadline, and the National Fire Protection Association (NFPA), which publishes the code, this week advanced AHRI’s request — a step toward a possible extension. 

Catch up quick: Before 2020, GFCI protection was not required for outdoor condenser connections. But in the 2020 NEC, the NFPA included a GFCI protection requirement for outdoor air conditioners and heat pumps.

• “Problems surfaced almost immediately,” Wes Davis, director of technical services at ACCA, told Homepros in July, as homeowners and contractors began reporting GFCI breakers tripping when ACs ran, “due to incompatibility with the equipment.”
• However, in August 2022, following an appeal led by ACCA and AHRI and backed by the National Association of Home Builders, the NFPA exempted outdoor HVAC equipment from the requirement until September 1, 2026 — an exemption that carried into the 2023 and 2026 editions. (A new NEC edition is published every three years.)

What’s happening: AHRI submitted an emergency Tentative Interim Amendment (TIA) to the NFPA, requesting it delay that deadline by two years, to September 1, 2028.

• The association’s request leans on its own research, which found that nuisance tripping primarily stems from the interaction between inverter-driven equipment and individual GFCI devices, explaining why the same HVAC system may trip one breaker but not another and indicating that a universal fix is unlikely. 
• The two-year extension marks a step down from an initial three-year ask, to September 1, 2029, which the TIA calls a “compromise” that will “allow the HVAC industry to finish its work.”

This week, the NFPA opened the amendment for public comment. 

What they’re saying: “If this date is not extended, many homeowners and tenants will be impacted by nuisance tripping incidents,” Tom Deary, AHRI’s senior director of codes, told Homepros in a statement. “These Tentative Interim Amendments will provide the industry with the time that it needs to resolve these incompatibility issues.”

Zoom out: When the exception was approved in 2022, the electrical industry committed to having special high-frequency (HF) GFCI devices — widely presented as a technical fix to nuisance tripping — commercially available by September 1, 2026, ACCA manager of codes and standards David Bixby wrote in late June.

• Yes, but: That promise hasn’t fully materialized, as HF GFCIs suitable for outdoor HVAC applications aren’t broadly available, Bixby noted, “nor have they been vetted at scale in real-world residential installations.”
• “Requiring contractors to install protection that does not yet reliably coexist with listed HVAC equipment exposes them to callbacks, downtime, and liability, without delivering corresponding safety benefits,” he added.

Of note: 25 states have independently removed the expiration date, clarified that HVAC equipment should be exempt, or deleted the requirement outright, according to AHRI, which didn’t specify the breakdown. 

• Those states fall within the 41 that, per the NFPA, have adopted the 2020, 2023, or 2026 NEC as of August 3. In those that have kept the provision intact, the requirement is set to take effect on September 1. 

Looking ahead: The NFPA’s public comment period is open until September 9, after which its Standards Council is expected to rule on the amendment shortly, according to a person familiar with the process. Industry stakeholders can submit a comment at the bottom of the TIA.

• A representative for the NFPA declined to speculate on the outcome.