IDA-201 Midterm Exam Prep pt.1

The two typical lubrication methods for ball-bearing motors are ________.

• oil port and permanently lubricated

• permanently lubricated and grease fittings

• oil ports and grease fittings

• drip and splash

The _________ is used with some motors to open the start windings after the motor has started.

• electronic relay

• run capacitor

• phase angle

• start capacitor

A positive temperature coefficient resistor (PTCR) ____________.

• decreases its resistance when its temperature increases

• opens a set of contacts when the main coil is magnetized

• increases its resistance as its temperature increases

• increases its resistance when its temperature decreases

The belt on a belt-driven motor must have the correct tension or the motor will _________.

Responses

• vibrate off its mount

• emit a loud noise and vibrate

• require a start capacitor for operation

• operate in an overloaded condition

Two types of motors that are commonly used for hermetic compressor motors are 

• single-phase open and shaded pole.

• open split-phase and hermetic split-phase.

• split-phase and permanent split capacitor (PSC)

• shaded pole and split-phase.

A _________ bearing surface must be used in a vertical shaft motor application.

• thrust

• sleeve

• greased

• ball

Two common operating voltages for residential equipment are

• 120 V and 240 V.

• 240 V and 277 V.

• 24 V and 240 V.

• 120 V and 24 V.

Three-phase motors have

• low starting torque.

• start capacitors wired into the starting circuit.

• high starting torque.

• run capacitors wired into the running circuit.

The amount by which the current leads or lags the voltage is called phase angle.

• True

• False

A motor that has two sets of windings, start and run, and has a start capacitor wired in series with its start windings is a ________________ motor.

• shaded-pole

• capacitor-start

• permanent split-capacitor

• three-phase