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Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2017 - Paper 1
Question 4
Refer to FIGURE 4.1 below and answer the questions that follow. 4.1.1 Name any TWO parts of the motor in FIGURE 4.1. 4.1.2 Explain how the direction of rotation of... show full transcript
Worked Solution & Example Answer:Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2017 - Paper 1
Step 1
Step 2
4.1.2 Explain how the direction of rotation of this motor may be reversed.
Answer
The direction of rotation of a three-phase induction motor can be reversed by swapping any two of the three power supply connections. This change alters the phase sequence, resulting in the rotor turning in the opposite direction.
Step 3
4.1.3 The stator of the motor may be connected in star or delta. Explain which connection would develop the greatest torque.
Answer
The delta connection will develop greater torque compared to the star connection. This is because, in a delta connection, the full line voltage is applied across each winding. As a result, the induced current and magnetic field strength increase, thereby generating higher torque.
Step 4
4.2 State ONE advantage of a three-phase induction motor over a single-phase induction motor.
Answer
One advantage of a three-phase induction motor is that it requires less maintenance than a single-phase motor. This is due to the smoother operation and higher efficiency, reducing wear and tear on the components.