BCTC Industrial Maintenance Technology AMTEC – NOCTI Mechatronic Assessment Practice Test 2026: The All-in-One Mastery Guide for Exam Success!

During startup, a capacitor-start motor needs the start winding energized through the capacitor to create the necessary phase shift for starting torque. The centrifugal switch physically closes to connect that capacitor in series with the start winding at low speed. Once the rotor reaches running speed, the switch opens, removing the start winding (and the capacitor) from the circuit so the motor runs on the run winding alone. That’s why the best statement is that it is closed at start up to place the capacitor in series with the start winding. The other options describe parts of the behavior but don’t capture the full startup function: the switch does not stay closed during run, it does not bypass the capacitor, and while it does open during run, the key point is its startup closure to engage the capacitor-start circuit.