Overview
IEC 60335-2-34:2012/AMD1:2015 is Amendment 1 to the IEC safety standard for household and similar electrical appliances - Part 2-34: Particular requirements for motor-compressors. This 2015 amendment (including the June 2015 corrigendum) updates definitions, test conditions and construction/marking requirements - notably to address R‑744 (CO2) refrigerant, flammable refrigerants, multi‑speed and variable‑capacity motor‑compressors, and high‑pressure testing.
Key topics and technical requirements
- Scope expansions
- Adds coverage for multi‑speed and variable‑capacity motor‑compressors and defines two‑stage motor‑compressors and cascade system testing rules.
- Refrigerant classifications
- Defines back‑pressure categories: LBP, MBP, HBP (evaporation temperature ranges) and classifies R‑744 use as transcritical or non‑transcritical.
- Markings & instructions
- Motor‑compressors suitable for flammable refrigerants must be marked with ISO 7010 W021 and list permissible refrigerants in instructions.
- Pressure and construction tests
- Specifies higher pressure test values for R‑744 (CO2) systems (e.g., minimums such as 3.5× saturated vapour pressure at 27 °C rounded to the next 0.5 MPa; or housing low‑side pressure tests of 5× saturated vapour at −6.5 °C or ≥13.5 MPa when applicable).
- Requirements for bypass valve pressure testing (minimum 3× maximum high‑side pressure or low‑side equivalents).
- Electrical and materials compatibility
- Annex BB: mandatory winding‑wire insulation compatibility tests with refrigerant/oil exposure cycles (time‑temperature profiles provided - e.g., heating cycles from 140 °C to 175 °C with defined total heating times).
- Annex CC: tie‑cord and insulation compatibility tests (normative).
- Components that may arc or spark when used with flammable refrigerants must comply with IEC 60079‑15 (type “n” protection), as modified by the standard’s Annex DD.
- Performance tests
- Updates to running overload and load condition tests (Annex AA) including R‑744‑specific pressure and temperature procedures for transcritical and non‑transcritical operation.
Applications and users
This amendment is essential for:
- Motor‑compressor manufacturers designing products for household and commercial refrigeration
- Test laboratories and certification bodies performing compliance verification and type testing
- HVACR designers, compliance engineers and safety assessors specifying motor‑compressors for systems using CO2 (R‑744) or flammable refrigerants
- Regulatory and standards committees aligning national adoption
Related standards
- IEC 60335‑1 (General requirements for household appliances)
- IEC 60079‑15 (Explosive atmospheres - equipment protection “n”) - referenced for flammable refrigerant components
- IEC 60851 series (winding wire test methods)
- ISO 7010 (graphical safety symbols)
This amendment guides safe design, testing and marking of motor‑compressors - especially for high‑pressure CO2 systems and appliances using flammable refrigerants - ensuring regulatory compliance and product safety.