210.8 Ground-Fault Circuit-Interrupter Protection for Personnel. ...(F) Outdoor Outlets. All outdoor outlets for dwellings, other than those covered in 210.8(A)(3), Exception to (3), that are supplied by single-phase branch circuits rated 150V to ground or less, 50A or less, shall have ground-fault circuit-interrupter protection for personnel. This requirement shall become effective January 1, 2023, for heating/ventilating/air-conditioning (HVAC) equipment.

Substantiation: GFCI protection was expanded in the 2020 NEC without HVAC component and equipment safety standards being harmonized with GFCI amperage limits. Currently, the UL standard that HVAC equipment is listed to (UL 1995) has no requirements for leakage current if the unit is hard wired, as most residential air conditioners/heat pumps are. In the future, HVAC equipment will be listed to UL 60335-2-40, which sets a limit of 10 milliamps of leakage current. However, this new standard is not mandatory until 1/1/2024. UL 943 is the standard to which GFCI breakers are listed and are required to trip at 5 milliamps of current. Even if HVAC equipment is listed to the UL 60335-2-40 standard, there is no guarantee it will be compatible with UL listed GFCI breakers This lack of coordination is what is leading to the nuisance tripping that customers are dealing with.

Until both equipment and component standards are updated, designers, installers, AHJs, and consumers are forced to choose between an NEC 2020 compliant installation or an operational installation. In jurisdictions that have adopted 2020 NEC with 210.8(F) intact, there have been numerous instances of field tripping of the GFCI breaker on ductless mini splits, units containing power conversion equipment, and on many single-stage units.