Overview - IEC TS 63542:2024 (Refrigerant detection systems for flammable refrigerants)
IEC TS 63542:2024 defines technical requirements and test methods for refrigerant detection systems used in appliances that employ flammable refrigerants (safety groups A2L, A2 and A3 as defined by ISO 817). The Technical Specification targets detection systems integrated into household and similar electrical appliances covered by relevant IEC 60335 series standards (for example, heat pumps, air‑conditioners, commercial refrigeration, refrigerant recovery and professional ice‑cream makers).
This document specifies how sensors must detect leaked refrigerant, how alarm set points relate to the refrigerant’s lower flammability limit (LFL), and the environmental, durability and safety tests the detection system must pass.
Key topics and technical requirements
- Scope and applicability: Applies only to refrigerants in ISO 817 groups A2L, A2 and A3 and to appliances covered by relevant IEC 60335 parts.
- Detection performance: Systems must give an output signal at a predetermined alarm set point and detect concentrations above that set point across the appliance’s full operating temperature and humidity range.
- Detection principle: Systems may detect refrigerant directly or detect gases displaced by leaked refrigerant.
- Test program and sample requirements: Specific clauses define tests for response time, calibration, selectivity, poisoning, oil spray, long‑term stability, humidity, temperature, vibration and ignition. Some tests are conducted on separate sets of three samples; all samples must pass.
- Calibration & stability: Requirements for short‑term calibration, drift, and demonstrating long‑term stability under expected operating conditions.
- Environmental and mechanical robustness: Includes humidity, temperature cycling and vibration tests, plus oil spray and refrigerant poisoning evaluations.
- Safety features: Self‑test routines, serviceability (sensor replacement notifications) and refrigerant sensor identification are required to support safe maintenance and lifecycle management.
- Reference to LFL: Where LFL is used, the appliance’s nominal refrigerant composition (per the application standard) is used for testing and set‑point selection.
Practical applications - who uses this standard
- Appliance manufacturers (heat pumps, air conditioners, commercial refrigeration, refrigerant recovery units, professional ice‑cream makers) integrating detection into products
- Sensor and detector OEMs designing refrigerant sensors for flammable refrigerants
- Test laboratories and certification bodies performing compliance testing to IEC 60335 application standards
- Safety and compliance engineers responsible for appliance design, risk assessment and user notification strategies
Related standards
By following IEC TS 63542:2024, manufacturers and test labs can ensure refrigerant detection systems meet harmonized performance, durability and safety expectations for appliances using flammable refrigerants.