Field Diverter Method of Speed Control of DC Series Motors: The field flux can be reduced by shunting a portion of motor current around the series field, thus reducing the excitation mmf and weakening of…
Starting of Synchronous Motor and Precautions: As already stated the synchronous motor has got no self starting torque and the motor must first be brought up to synchronous speed by some external means before it…
Star Delta Starter Working Principle and Circuit Diagram: This star delta starter method of starting of cage induction motors is based upon the principle that with 3 windings connected in star, the voltage across each winding…
Auto Transformer Starter - Working Principle, Advantages and Disadvantages: In auto transformer starter method the reduced voltage is obtained by taking tappings at suitable points from a three phase auto-transformer, as shown in Fig. 1.70(a).…
Primary Resistance Starter - Operation, Wiring Diagram, Advantages and Disadvantages: This method of primary resistance starter of a polyphase cage motor is very simple and provides smooth acceleration of the motor. In this method of…
Starting of Squirrel Cage Induction Motor: Direct-on-Line Starting or Full-Voltage Starting - As already mentioned, squirrel-cage induction motors, as a general rule, up to 4 or 5 kW are started by this method. As the…
Starting of Slip Ring Induction Motor: The starting of slip ring induction motor is given below, At start, speed of motor is zero and, therefore, slip s = 1.0. Substituting s = 1.0 in Eqs.…
Counter Emf Automatic Starter - Working Principle and its Drawbacks: This type of starter depends upon the build up of the back or counter emf to operate the contactors (a heavy duty relay designed to…
Drum Controller for DC Series Motor: DC series motors are often employed on cranes, elevators, tramcars and other applications, where the motor is under the direct control of an operator. In these applications, frequent starting,…
DC Series Motor Starter Working Principle: The series motor starter serves the same purpose as the three- and four-point starters employed with shunt and compound wound motors. However, series motor starter has different internal and…
