Air Conditioning Repair Service 5

Question 1

A technician finds acid in the compressor oil during a burnout analysis. After replacing the compressor, which additional service step is MOST critical?

Accepted Answer

Install a new filter drier and perform a system flush

Answer

Acid from a burnout contaminates the entire system, and a new filter drier with acid-absorption capability, along with flushing, is essential to prevent repeat failure.

Question 2

What is the recommended method to verify proper refrigerant charge on a fixed-orifice (piston) metering device system?

Accepted Answer

Target a superheat of 10–18°F at the evaporator outlet under standard conditions

Answer

Fixed-orifice systems are charged using superheat method, typically targeting 10–18°F at the evaporator outlet to ensure proper refrigerant feed without flooding.

Question 3

During a service call, a technician confirms low refrigerant charge. Before adding refrigerant, the technician should:

Accepted Answer

Locate and repair the leak first

Answer

EPA regulations and good practice require finding and repairing leaks before recharging, as simply topping off a leaking system wastes refrigerant and is non-compliant.

Question 4

A condenser fan motor runs but the blade is not turning. The MOST likely cause is:

Accepted Answer

Broken or loose fan blade set screw

Answer

If the motor shaft spins but the blade does not move, the fan blade's set screw or retaining hardware has failed, disconnecting the blade from the shaft.

Question 5

What is the purpose of the suction line accumulator in an air conditioning system?

Accepted Answer

To prevent liquid refrigerant from entering the compressor

Answer

The accumulator is located on the suction line and holds excess liquid refrigerant, allowing only vapor to enter the compressor and preventing liquid slugging.

Air Conditioning Repair Practice Test

Air Conditioning Repair Practice Test

Air Conditioning Repair Service 5