A single-phase split-phase induction motor...

Question 1 of 270705eccefa4bacbc34ba4d4825f

A single-phase split-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. What motor component most likely is faulty?

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Question 1 of 27070

🔍 Key Concepts

• Split-phase induction motor components: starting (auxiliary) winding vs running (main) winding • Centrifugal switch/mechanism function: how and when the start winding is taken out of the circuit • Normal symptoms of open start winding vs open run winding vs stuck centrifugal switch

💭 Think About

• Think about which component is responsible for providing the initial phase shift (torque) to get the motor started from rest. • Once the rotor is up to speed, which winding is supposed to carry the load continuously, and what would happen if that winding were not working properly? • If the motor only runs when you spin it and then alternates between very slow and about half-speed, which part failing would cause the motor to keep trying to start over and over instead of running smoothly at full speed?

✅ Before You Answer

• Identify which winding (starting or running) is only used briefly during startup, and which is used all the time during normal running. • Consider which fault would cause no self-start, but allow some rotation if you give it a manual spin. • Decide whether a bad mechanism/switch versus a bad winding would better explain the repeated slow/half-speed behavior.