... achieve the purpose of regulating motor speed by changing the motor rotor resistance wound motor speed control device I, mainly features:1 ... and maintenance are convenient.II, Application:Applicable to three-phase AC 380V 660V, 3KV, 6KV,10KV drag fan and pump type ... load of winding type asynchronous motor soft starter speed control, and slip little changed (S≈0.1) , about laden ...