IDA-201 Midterm Exam Prep pt.5

An electronically commutated motor (ECM) is made up of two components, the 

• controls and the motor.

• motor and the shaft.

• motor mount and the motor.

• stator and the rotor.

A start capacitor is wired into the circuit to provide the most efficient phase angle between the current and voltage when the motor is running.

• True

• False

The two transformer configurations commonly used for commercial and industrial applications are

• 50 and 60 cycles per second (cps).

• wye and delta.

• single-phase and three-phase.

• primary and secondary.

An open single-phase motor with a centrifugal starting switch may not be used in 

• an air-conditioning condenser fan motor.

• a ventilating fan motor.

• an area where explosive gases exist.

• an air-conditioning indoor air handler.

The converter

• is a switch

• changes the frequency of the power

• changes AC to DC

• is used only with DC motors

The voltage generated by an electric motor’s rotor turning within a motor is known as

• drop-out voltage.

• continuous coil voltage.

• back electromotive force (BEMF).

• pick-up voltage.

Cradle, rigid-base, end, and belly-band are all types of _________.

• mounting styles

• bearings

• insulation types

• lubrication methods

In a single-phase motor, the motor windings that have the highest resistance are the __________ windings.

• rotor

• run

• start

• shaft

Two-speed compressor motors are used by some manufacturers to

• increase starting torque.

• control capacity.

• run at varying voltages.

• run on single-phase and three-phase power supplies.

A drive mechanism transfers a motor’s energy to the __________.

• device being driven

• motor housing

• vibration eliminator

• motor mount