Refrigeration System Knowledge Assessment

What is the primary purpose of a moisture indicating sight glass in a refrigeration system?

• To check the refrigerant level

• To check the refrigerant for moisture

• To measure the pressure of the refrigerant

• To regulate the flow of refrigerant

Why should the liquid-line filter drier be replaced anytime a system is opened for service?

• It becomes clogged with refrigerant

• It loses its ability to filter moisture

• It is a regulatory requirement

• It is a standard maintenance procedure

What is the consequence of closing the discharge service valve on an operating reciprocating compressor?

• It will increase the efficiency of the compressor

• It can result in compressor damage and severe personal injury

• It will decrease the system pressure

• It will improve the cooling capacity

How does a crankcase heater help in a refrigeration system?

• By increasing the refrigerant pressure

• By reducing the amount of refrigerant in the oil and reducing oil foaming

• By cooling the compressor

• By increasing the system's cooling capacity

What is the purpose of using nitrogen when evacuating a system with large amounts of moisture?

• To increase the system pressure

• To counteract freezing of the moisture

• To reduce the refrigerant charge

• To improve the efficiency of the vacuum pump

Why is it important to maintain system pressure slightly above atmospheric pressure in an idled low-pressure refrigeration system?

• To prevent refrigerant loss

• To prevent air accumulation

• To increase system efficiency

• To reduce maintenance costs

What is the maximum test pressure when leak testing a low-pressure centrifugal chiller with nitrogen?

• 5 psig

• 10 psig

• 15 psig

• 20 psig

What is the role of a purge unit in a low-pressure chiller system?

• To increase refrigerant pressure

• To remove non-condensables that leak into the system

• To add refrigerant to the system

• To cool the refrigerant

According to ASHRAE Guideline 3, when should a system be checked for leaks during a standard vacuum test?

• If the pressure rises from 1 mm Hg to above 2.5 mm Hg

• If the pressure remains constant at 1 mm Hg

• If the pressure drops below 1 mm Hg

• If the pressure rises to 5 mm Hg

What is the EPA's maximum allowable leak rate for appliances used for comfort cooling as of January 1, 2019?

• 5% of the charge per year

• 10% of the charge per year

• 20% of the charge per year

• 30% of the charge per year