Step 1 :To set up the connection diagram of the given system:
Connect the 3-phase supply to the input terminal of the autotransformer.
Connect two output terminals of the autotransformer to a voltmeter.
Connect any two output terminals of the autotransformer to the terminals of the motor.
Connect one output terminal of the autotransformer and one terminal of the motor to an ammeter.
Step 2 : Click on MCB switch to start the power and note the phase. Initially it’s in RBY phase and can changed further.
Step 3 : Put on the switch of Autotransformer to start the motor.
Step 4 : Note the direction of rotor, which depends on the phase that we set using phase switch.
Step 5 : Click on the TACHOMETER to obtain the speed of the motor and note it down
Step 6 : Put off the switch of Autotransformer when you wish to stop the rotor.
Step 7 : We can change the phase only by switching off the MCB.
Step 8 : Repeat the steps from 2 to 6 and each time note the direction of rotor and RPM from Tachometer.