Electric motors questions with correct answers 2023

Electric motors questions with correct answers 2023The two popular operating voltages for residence are - correct answer 115 and 230 volts When an open motor gets up to speed the start switch - correct answer takes the start winding out of the circuit. The start windings resistance is - correct answer The start windings resistance is greater than that of the run winding The start capacitor is - correct answer wired in series with the start winding for more starting torque. A run capacitor - correct answer A run capacitor improves the running efficiency of the split phase motor what is BEMF - correct answer Back electromotor force - The large metal mass of the rotors motor turning at high speeds with the motor windings in close proximity has a voltage generating effect this is greater across the start winding because it is wound with longer thinner wire. It is often referred to as inductive voltage or BEMF why is a compressor motor manufacture from special material - correct answer Because the compressor motor materials must be compatible with the refrigerant and oil circulating in the system Two types of motors used for hermetic compressors are - correct answer Refrigerant gas cooled and air from a fan cooled why cant a centrifugal switch be used inside a hermetic compressor - correct answer A spark will deteriorate the refrigerant, so the leads must pass thru the compressor shell to the outside Two types of relays to start hermetic compressors are - correct answer The potential relay and the Current relay A PTC device is used - correct answer with some PSC motors to give small amounts of starting torque. Three phase motors have ..... starting torque - correct answer small starting torque