Single-phase induction motor noise caused by improper manufacturer design

Single-Phase induction motors are used in simple industrial applications very often. This article deals with a singlephase motor fan used in heating system of industry buildings. Single-phase distribution of electricity is cheaper and simpler. However, it brings some disadvantages in using electric machines such as induction motors. The analysis shows problems of using slip to control velocity by supplying voltage. Bad design of both auxiliary and main winding together with capacity control can produce noise that is not acceptable in an application of heating systems. The effect of the bad design is presented in this paper. The possibility of velocity control from a variable frequency power supply is discussed as well.