Refrigeration System Quiz

What effect does a partially blocked capillary tube have on a refrigeration system?

• Higher than normal suction pressure

• Increased refrigerant flow to the evaporator

• Starving the evaporator and lowering suction pressure

• Lower than normal compressor amperage draw

When performing a vacuum on a refrigeration system, what is the recommended level to ensure proper dehydration?

• 500 microns or lower

• 10 inHg

• 29.92 inHg absolute

• 2000 microns

What happens if a refrigeration system is overcharged?

• Suction pressure increases and discharge pressure decreases

• Superheat increases and subcooling decreases

• Liquid refrigerant may flood back to the compressor, causing damage

• The compressor will short-cycle due to lack of refrigerant

A compressor’s windings are checked with an ohmmeter. The technician finds that all windings show resistance to ground. What does this indicate?

• The windings are open

• The compressor motor is grounded and needs replacement

• The start capacitor has failed

• The compressor is running normally

What will happen if a refrigeration system has a defective condenser fan motor?

• Suction pressure will drop significantly

• Head pressure will rise excessively

• The evaporator will frost over

• The system will cycle off due to low pressure

If a thermostatic expansion valve (TXV) sensing bulb loses its charge, what will be the result?

• The evaporator will overheat

• The compressor will run continuously

• The system will operate normally

• The valve will close, starving the evaporator

What is the primary purpose of a liquid line filter-drier?

• To regulate refrigerant flow to the evaporator

• To remove moisture and contaminants from the refrigerant

• To act as an expansion device

• To increase the velocity of refrigerant in the liquid line

A compressor is operating with high discharge temperature and low suction pressure. What could be the cause?

• Overcharged system

• Low refrigerant charge or restriction

• Faulty condenser fan motor

• Oversized metering device

What effect does non-condensable gases in a refrigeration system have on performance?

• Increased head pressure and reduced system efficiency

• Decreased compressor discharge temperature

• Increased subcooling in the condenser

• No impact, as they circulate with the refrigerant

What is the purpose of a hot gas defrost system in a refrigeration unit?

• To remove ice from the evaporator using high-pressure refrigerant vapor

• To increase superheat in the suction line

• To allow refrigerant to flow directly to the evaporator

• To maintain head pressure in low ambient conditions