Air Conditioning Repair Service 2

Question 1

When performing a refrigerant recovery, the technician should recover the refrigerant until the system pressure reaches:

Accepted Answer

0 psig or as low as possible

Answer

EPA regulations require recovering refrigerant to 0 psig or as low as the recovery machine can achieve to minimize emissions.

Question 2

A technician notices that the evaporator coil is icing up during operation. Which service step should be performed FIRST?

Accepted Answer

Check airflow across the evaporator

Answer

Restricted airflow is the most common cause of evaporator icing, and checking it first eliminates the simplest root cause before invasive repairs.

Question 3

What is the purpose of performing a standing pressure test on a system after repair?

Accepted Answer

To verify no leaks exist before charging with refrigerant

Answer

A standing pressure test uses dry nitrogen to verify system integrity and confirm no leaks are present before introducing refrigerant.

Question 4

Which oil is required for use in systems containing R-410A refrigerant?

Accepted Answer

POE (polyolester) oil

Answer

R-410A systems require POE (polyolester) oil because it is miscible with HFC refrigerants, ensuring proper lubrication throughout the system.

Question 5

During a service call, a technician measures suction pressure lower than normal and discharge pressure lower than normal. This most likely indicates:

Accepted Answer

Low refrigerant charge

Answer

Both suction and discharge pressures below normal simultaneously is a classic indicator of an undercharged (low refrigerant) system.

Air Conditioning Repair Practice Test