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Noise level

The international limits of noise produced by general purpose electric motors are defined in IEC 60 034-9, with which our standard range of motors comply. There are 3 main sources of noise : 1. Magnetic forces which tend the stator core radial oscillations. 2. Bearings which generate noise due to imperfections in the geometry of the balls and rollers. 3. Cooling fan which generates so called ventilation noise. Among these 3 main sources of noise, the ventilation noise is the most dominating factor especially on large motors. Special measures for further noise limitation can be taken on request.