Exam 4: Air-Conditioning System Operating Principlesthe Manifold and Gauge Set

Technician A says the Schrader-type service valve is automatically opened when the service hose is installed.Technician B says the Schrader-type service valve is automatically closed when the service hose is removed.Who is correct?

Explain why low pressure must be maintained in the evaporator.

Where in the system is the receiver dryer located?

The refrigerant entering the condenser is in the liquid state.

When relative humidity is high,the air conditioner must work harder than when relative humidity is low.

Technician A says there is a common passage on a manifold and gauge set.Technician B says both hand valves on a manifold and gauge set must be closed to read service pressures.Who is correct?

All of the following statements about the hand valves in an air conditioning gauge manifold are true,EXCEPT:

What is the heart of the refrigerant system?

What is one of the dividing points between the high and low sides of the refrigerant system?

Technician A says the CFC-12 (R-12)service manifold hose fitting must be 1/2-inch male refrigerant flare nut at each end. Technician A says HFC-134a (R-134a)service manifold hoses use an ACME female nut.Who is correct?

What is the basic function of the automotive air conditioning system?

What is R-134a chemically? It is referred to as what?

What is the heart of the refrigerant system?

Performance testing on air conditioning is being discussed.Technician A says the engine should be operated at speeds over 3,000 rpm during the test.Technician B says a fan should be used to force air through the condenser and radiator.Who is correct?

Where is the refrigerant system desiccant located?

A modern air conditioner system will have either an accumulator or a receiver-drier but not both.

Explain why high pressure must be maintained in the condenser.

Under normal operating conditions all of the following occurs inside the evaporator,EXCEPT:

What does the term relative humidity mean?

What state is the refrigerant in the condenser?