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.