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Part 9 of the IEC 60034 series focuses exclusively on . It applies to rotating electrical machines (motors and generators) of standard design. The standard details: Maximum sound power levels ( LWcap L sub cap W Test methods for measuring noise. iec 60034-9 pdf free download
It references ISO 3740 series for the actual acoustic measurement methods, ensuring consistency across the industry. Why You Can’t Find a Legal "Free Download" "Free PDF" sites are notorious for including "drive-by"
The official source for the most recent version (currently IEC 60034-9:2021 ). iec 60034-9 pdf free download