ASF Refrigeration Systems and Heat Transfer 3

Question 1

A refrigerator is not maintaining proper temperature. Which area should a technician inspect FIRST before considering component replacement?

Accepted Answer

Check if the condenser coils are dirty or airflow is restricted

Answer

Replace the compressor immediately

Answer

Recharge the refrigerant to factory specifications

Answer

Replace the thermostat or temperature control

Question 2

A refrigeration system shows high suction pressure and low discharge pressure. What does this most likely indicate?

Accepted Answer

The compressor has failing or worn internal valves

Answer

The system is overcharged with refrigerant

Answer

The expansion valve is severely restricted or clogged

Answer

The condenser fan motor has stopped running

Question 3

What instrument does a refrigeration technician use to simultaneously read both high-side and low-side system pressures?

Accepted Answer

Manifold gauge set

Answer

Digital multimeter

Answer

Clamp meter

Answer

Megohmmeter

Question 4

What is the recommended method for locating refrigerant leaks in a sealed refrigeration system?

Accepted Answer

Use an electronic leak detector or apply a soapy water solution to suspect areas

Answer

Smell around the system for refrigerant odors

Answer

Add refrigerant and monitor pressure drop over time

Answer

Check the compressor amperage draw for abnormalities

Question 5

A technician observes that the evaporator in a refrigerator is completely encased in ice. What is the MOST likely cause?

Accepted Answer

The defrost system has failed and is not melting accumulated frost

Answer

The system is overcharged with refrigerant

Answer

The condenser fan motor is running at excessive speed

Answer

The compressor is operating at too high a capacity

Question 6

Before opening a refrigeration system for service, what is the MOST critical regulatory requirement regarding refrigerant?

Accepted Answer

Recover the refrigerant using EPA-certified equipment before opening the system

Answer

Ensure the appliance is unplugged and at room temperature

Answer

Vent the refrigerant slowly to reduce system pressure safely

Answer

Run the compressor briefly to circulate and warm the refrigerant

Question 7

What is the purpose of an accumulator located on the suction line of a refrigeration system?

Accepted Answer

To store excess refrigerant and prevent liquid slugging into the compressor

Answer

To increase compressor discharge pressure for better heat rejection

Answer

To filter contaminants from refrigerant before it reaches the condenser

Answer

To regulate evaporator temperature by controlling refrigerant flow