The mode of anti-switching of the electric drive during the reverse rotation of the impeller of the fan and pumping units

The article discusses the causes of the occurrence of such a phenomenon as the rotation of the impeller of a fan or pump located in the technological reserve, under the action of a reverse flow of the working medium. The negative consequences of the reverse rotation mode of the fan impeller or pump for the electric motor are considered in detail. The article discusses ways of picking up electric drives of fan and pumping units during reverse rotation of the impeller. It is shown that the existing methods for determining the initial speed and the pickup of the rotor are focused on the self-starting of the electric motor when power is lost, at which the rotor rotates in the normal direction. A method for picking up a frequency converter is proposed, which allows to determine the frequency and direction of rotation of the rotor, thereby ensuring the pickup and successful start of the electric motor with the reverse direction of rotation.