关键词: A2L制冷剂, 开口限值, 点火源测试, R32

Abstract: To ensure the safe application of R32 refrigerant (an A2L mildly flammable refrigerant) in air conditioning systems, investigates ignition source testing for electrical components in response to the newly added flame-retardant enclosure verification test requirements in the GB/T 4706.32—2024 standard. By analyzing the opening size limits for relay contacts and similar components specified in the standard (equivalent diameter ≤ 2.8 mm), designed and constructed an integrated test platform comprising a gas-mixing system, a high-voltage ignition device (15 kV/30 mA), video monitoring, and pH detection. This platform establishes a complete testing process for combustible gas mixing, ignition, and flame propagation. Experimental optimizations included refrigerant uniformity control (adding a circulation fan) and safety pressure-relief devices (vent holes covered with packing film on the enclosure lid), which validated the feasibility of the alternative ignition test. provides operable technical solutions for air conditioning manufacturers and testing institutions to implement the standard, effectively mitigating the risk of R32 refrigerant ignition and explosion caused by electrical arcing in components.

Key words: A2L refrigerant, Opening size limits, Ignition source testing, R32