IDA-201 Midterm Exam Prep pt.6

Power enters a hermetic compressor shell and passes to the motor inside using 

• start and/or run capacitors.

• DC converters.

• insulated motor terminals.

• separate motor windings.

Which of the following devices may be wired into the starting circuit of a motor to improve the starting torque?

• Start capacitor

• Thermostat

• Centrifugal Switch

• Another winding

Capacitors are used after the converter to

• reduce the voltage

• suppress the noise

• smooth out the DC current

• change the voltage fequency

Using evaporator pressure, condensing pressure, and compressor current, which of the following can be used to verify proper compressor operation?

• Belt tension tool

• Amperage performance chart

• Superheat calculator

• Power supply data

Large motors with a horsepower greater than 5 are typically ___________ motors.

• three-phase

• low-voltage

• single-phse

• split-phase

The difference between a motor’s calculated speed and its actual speed is known as 

• full-load amperes.

• starting torque.

• Induction

• motor slip.

Power supply data should include which of the following?

• Service factor, service factor amperage, insulation class, and capacitance

• Bearing types, mounting characteristics, and drive mechanism

• Voltage, current capacity, frequency, and phase

• Voltage, service factor, shaft rotation, and capacitance 

A PTCR device is used

• as a pressure protection device.

• as a compressor starting device.

• as a motor protection device.

• to increase motor running efficiency. 

A hermetic motor that is cooled by suction gas must have a(n) ______________ to be cooled properly.

• refrigerant overcharge

• accumulator

• liquid receiver

• adequate refrigerant charge

A _________ receives a fixed DC voltage from the converter and then pulses the voltage to the motor.

• diode bridge

• rectifier

• capacitor bank

• pulse-width modulator