Question 1

Most original equipment manufacturers use what type of lubricant in their R-134a systems?
A) Mineral
B) Ester
C) Paraffinc
D) PAG

Accepted Answer

C

Question 2

When the air conditioning system is operating,the suction line should feel hot to the touch.

Accepted Answer

When the air conditioning system is operating, the suction line should feel cool or even cold to the touch, as it is carrying refrigerant back to the compressor from the evaporator. A hot suction line could indicate a problem with the system, such as a restriction or improper refrigerant flow.

Question 3

When the air conditioning system is operating,the discharge line should feel hot to the touch.

Accepted Answer

The discharge line carries hot refrigerant from the compressor to the condenser. Therefore, when the air conditioning system is operating, the discharge line should feel hot to the touch.

Question 4

Technician A says that the evacuation process will remove dirt and debris from the refrigerant system.Technician B says that the evacuation process will remove moisture and air from the refrigerant system.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

The evacuation process in a refrigerant system is designed to remove moisture and air, not dirt and debris. Technician B is correct.

Question 5

The pressure of the bulk recovery tank can be tested to identify refrigerant cross contamination.

Accepted Answer

The pressure of the bulk recovery tank can be tested to identify refrigerant cross-contamination. If the pressure is higher than expected, it can indicate that there is another refrigerant mixed in with the recovered refrigerant. This can cause issues with system performance and potential damage if the wrong type of refrigerant is used.

Question 6

A leak may be marked by the presence of refrigeration oil.

Accepted Answer

A refrigeration leak may be identified by the presence of refrigeration oil, which indicates that refrigerant is escaping from the system.

Question 7

Technician Asays a soap solution must be used in well-ventilated spaces only.Technician B says leaks often occur in areas of limited access where it is difficult to use a halogen leak detector.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

The answer of Technician Asays a soap solution must be...

Question 8

R-134a and R-12 systems use the same refrigerant oil.

Accepted Answer

R-134a systems typically use a polyalkylene glycol (PAG) oil, while R-12 systems use mineral oil. These oils are not interchangeable due to their different chemical properties and compatibility with the refrigerant.

Question 9

All of the following statements about system evacuation are true,EXCEPT:
A) Water boils at a lower temperature at higher altitudes.
B) Vacuum pump efficiency is increased at higher altitudes.
C) At high altitudes, ambient temperature must be raised for the vacuum pump to efficiently remove moisture.
D) Running the vehicle engine will raise the temperature of the underhood components.

Accepted Answer

Vacuum pump efficiency actually decreases at higher altitudes due to the reduced atmospheric pressure, making it harder to create a strong vacuum.

Question 10

Refrigeration oil circulates with the refrigerant through the system.

Accepted Answer

Refrigeration oil is a lubricant that helps to keep the compressor running smoothly. It circulates along with the refrigerant to lubricate the various components of the system, including the compressor itself. However, it is important to note that refrigeration oil does not mix with the refrigerant and remains separate from it throughout the system.

Question 11

An air conditioning system should be pumped down (evacuated)for a minimum of ____ minutes.
A) 10
B) 20
C) 30
D) 60

Accepted Answer

An air conditioning system should be evacuated for a minimum of 30 minutes to ensure that all moisture and non-condensable gases have been removed from the system. This is necessary to ensure efficient and reliable operation of the system. Shorter evacuation times may leave some moisture and non-condensable gases in the system, which can lead to problems such as corrosion, refrigerant contamination, and reduced system performance.

Question 12

R-134a is more likely to absorb moisture than R-12.

Accepted Answer

R-134a is a hydrofluorocarbon (HFC) refrigerant that is hygroscopic, meaning it has the tendency to absorb moisture from the atmosphere. R-12, on the other hand, is a chlorofluorocarbon (CFC) refrigerant that is not as prone to absorbing moisture.

Question 13

The electronic (halogen)leak detector is the most expensive and sensitive of all leak detection devices.

Accepted Answer

The electronic (halogen) leak detector is indeed the most expensive and sensitive of all leak detection devices, making it a popular choice for HVAC technicians and refrigeration professionals.

Question 14

A fluorescent leak detector will only work after a special dye is injected into the system.

Accepted Answer

This is because the fluorescent leak detector relies on the dye that has been added to the system to detect any leaks. Without the dye, the detector will not be able to detect any leaks.

Question 15

Technician A says that the electronic leak detector probe should be held directly against a suspected leak area during a eak test.Technician B says that the electronic leak detector requires routine calibration and probe tip inspection and maintenance.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Technician B is correct because electronic leak detectors do require routine calibration and probe tip inspection and maintenance to function accurately. Holding the probe directly against a suspected leak area, as Technician A suggests, is not always necessary or recommended, as the proper technique often involves moving the probe slowly around the suspected leak area to detect the presence of refrigerants or gases.

Question 16

Refrigerant vapors are lighter than air.

Accepted Answer

Most refrigerant vapors, including commonly used ones like R-134a and R-22, are heavier than air, meaning they tend to settle in low-lying areas when leaked.

Question 17

All of the following statements about injecting a dye solution into the air conditioning system are true,EXCEPT:
A) Dye is approved for automotive air conditioning system use.
B) The dye affects the overall performance of the system.
C) Dye is available in either yellow or red.
D) A few days after injection, the dye will be visible at the point of the leak.

Accepted Answer

Injecting dye into the air conditioning system does not affect the overall performance of the system. It is added only to help locate leaks in the system by making them visible under UV light.

Question 18

When making system repairs,install the receiver-drier or accumulator
A) first.
B) last.
C) after evacuating the system.
D) any time.

Accepted Answer

The receiver-drier or accumulator should be installed last after all other repairs have been made and the system has been evacuated. This helps to prevent moisture and other contaminants from entering the system during the repair process.

Question 19

Technician A says the performance test is a way of measuring system pressures.Technician B says the performance test is a way of measuring the outside humidity.Who is correct? A) Technician A only B) Technician B only C) Both A and B D) Neither A nor B

Accepted Answer

Technician A is correct. The performance test involves measuring the pressure and performance of various systems and components, including air conditioning systems. Technician B is incorrect, as the performance test does not measure outside humidity.

Question 20

System malfunctions cannot be detected by visual inspection.

Accepted Answer

Visual inspection may help detect some external damages or abnormalities, but it cannot detect malfunctions in the internal system of a device, which often require specialized tools and testing.

Quiz 6: Refrigerant System Servicing and Testingair-Conditioning System Servicing and Testing

Most original equipment manufacturers use what type of lubricant in their R-134a systems?

When the air conditioning system is operating,the suction line should feel hot to the touch.

When the air conditioning system is operating,the discharge line should feel hot to the touch.

Technician A says that the evacuation process will remove dirt and debris from the refrigerant system.Technician B says that the evacuation process will remove moisture and air from the refrigerant system.Who is correct?

The pressure of the bulk recovery tank can be tested to identify refrigerant cross contamination.

A leak may be marked by the presence of refrigeration oil.

Technician Asays a soap solution must be used in well-ventilated spaces only.Technician B says leaks often occur in areas of limited access where it is difficult to use a halogen leak detector.Who is correct?

R-134a and R-12 systems use the same refrigerant oil.

All of the following statements about system evacuation are true,EXCEPT:

Refrigeration oil circulates with the refrigerant through the system.

An air conditioning system should be pumped down (evacuated) for a minimum of ____ minutes.

R-134a is more likely to absorb moisture than R-12.

The electronic (halogen)leak detector is the most expensive and sensitive of all leak detection devices.

A fluorescent leak detector will only work after a special dye is injected into the system.

Technician A says that the electronic leak detector probe should be held directly against a suspected leak area during a eak test.Technician B says that the electronic leak detector requires routine calibration and probe tip inspection and maintenance.Who is correct?

Refrigerant vapors are lighter than air.

All of the following statements about injecting a dye solution into the air conditioning system are true,EXCEPT:

When making system repairs,install the receiver-drier or accumulator

Technician A says the performance test is a way of measuring system pressures.Technician B says the performance test is a way of measuring the outside humidity.Who is correct?

System malfunctions cannot be detected by visual inspection.