Exam 7: Diagnosis of the Refrigeration System

Which of the following is NOT a symptom of an overcharged air conditioning system?

Poor passenger compartment cooling may be the result of dirt or debris plugging the evaporator core cooling fins.

O-ring damage could be caused by

An R-134a expansion valve system that is properly charged has the following gauge readings,high-side 150 psig and low-side 42 psig and the ambient air temperature is 85°F.Which of the following is the most likely cause?

A pressure gauge reading of 26 psig (179 kPa)inside the evaporator of a system using R-134a means the evaporating temperature of the refrigerant is about

A technician is checking refrigerant system pressures.Both high- and ow-side service ports are located on the A/C compressor.When the compressor is engaged,the high-side pressure instantly goes over 375 psig.What is the most ikely cause of this condition?

How does the technician determine whether an excessively low gauge reading is caused by a clogged screen or by moisture in the system?

A manifold and gauge set is attached to an operating air conditioner.The low-side gauge reading is too high and the high-side reading is too low.What could be the problem?

While a technician is performing an A/C system performance test,it is determined that the low pressure gauge is reading in the vacuum range.This reading could be caused by:

Restricted airflow through the condenser core will result in higher than normal high-side pressures.

What is the symptom of a refrigerant system that is overcharges with refrigerant?

What can a defective compressor cause systems pressures to be?

What effect would a high-side restriction have on a system and how would it be detected?

What are most restrictions in a refrigerant system are caused by?

What is the primary cause of corrosion in the air-conditioning system?

A refrigerant system with air contamination will still operate properly.

On a cycling-clutch system,the desired average temperature of the evaporator should be about 35°F (1.7°C).

What are the possible causes of a low-side pressure that is high (45 psig),and a high-side pressure that is low (150 psig)?

R-134a has the exact same temperature and pressure relationship as R-12.

On a properly charged R-134a system an A/C performance test indicates both normal high- and low-side pressures,but poor cooling.Which of the following is the most likely cause?