EPA Section 608 Technician Certification
Exam
What are the typical uses of the center port of gauge set? - correct Answers-Used
during evacuation, charging and recovery procedures.
What color are the gauges on a manifold gauge set? - correct Answers-Low pressure is
blue, High pressure is red.
What are the typical ranges of pressure measurements used on the gauges of a
manifold gauge set? - correct Answers-High side is 0 to 500 PSIG; Low side is 0 to 350
PSIG and 0 to 30 in. Hg below atmospheric pressure.
Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas? -
correct Answers-High pressure, liquid.
Is the refrigerant entering the expansion valve (variable metering device) a liquid or
gas? - correct Answers-Liquid, high pressure.
Is the pressure of the refrigerant entering the compressor high or low? - correct
Answers-Low pressure vapor.
Where in a refrigerant circuit does a liquid boil to absorb heat? - correct Answers-In the
evaporator.
The refrigerant in the suction line is a gas that has been heated above its saturation.
What is this condition called? - correct Answers-Superheated vapor.
What can cause liquid refrigerant to migrate to a compressor crankcase? - correct
Answers-If the compressor is located in the coldest location in the circuit.
List two conditions that can quickly damage a compressor that is starting to run? -
correct Answers-Operating while in a deep vacuum or when the service valves are
closed.
What system failures require taking an oil sample? - correct Answers-A compressor
burnout or if the unit has had a leak.
Is flushing with refrigerant an acceptable tube cleaning method? - correct Answers-No.
,In addition to preventing and repairing leaks what else should a technician do to
conserve refrigerant? - correct Answers-Recover and recycle used refrigerants.
What factors affect the speed of an evacuation? - correct Answers-Pump size, hose
length, hose diameter, size of system to be evacuated, ambient temperature, suction
line size, and the amount of moisture in the system.
How should gauge set hoses be sized for use in evacuating a system? - correct
Answers-Use the shortest length and the largest diameter possible for the quickest
evacuation. At least as large as the vacuum pump inlet.
When evacuating what is the benefit of using short hoses with large diameters? -
correct Answers-Reduces emissions, pressure drop and evacuation time.
Which connection determines the preferred size of hoses used with a vacuum pump? -
correct Answers-The vacuum pump inlet.
As the capacity and suction hose size increase what happens to the time needed for an
evacuation? - correct Answers-Time is reduced.
What purpose is served by heating a system during dehydration? - correct Answers-To
speed up moisture removal.
Does a thorough evacuation remove moisture from a system? - correct Answers-Yes.
What can happen to oil in the compressor if the moisture is left in an operating system?
- correct Answers-The oil will form hydrofluoric and hydrochloric acids which will corrode
the internal parts of the system.
What is the result of over-evacuating a system? - correct Answers-No damage will be
done.
How can a system be leak checked using a low pressure gauge? - correct Answers-
Vacuum reading will rise when vacuum pump is turned off.
How close should the vacuum gauge be connected to the vacuum pump during
evacuation? - correct Answers-As far away as possible.
When measuring the vacuum of a system being evacuated the system must be isolated.
What must be done to the vacuum pump? - correct Answers-Turn it off and valve it off.
What is ozone? - correct Answers-3 atoms of oxygen. It blocks much of the harmful
ultraviolet radiation (uv-b) emitted from the sun and it keeps our earth's temperature
stable.
, How much ozone can a chlorine atom destroy in the stratosphere? - correct Answers-
One atom can destroy 100,000 ozone molecules.
What is Ozone Depletion Potential (ODP)? - correct Answers-The ability of any
chemical to deplete the ozone layer.
What is CFC? - correct Answers-Chlorofluorocarbon.
Which refrigerants are CFC's? - correct Answers-R-11,12,113,114.
Which chemical in the CFC refrigerants does the most damage to the ozone layer? -
correct Answers-Chlorine.
What is an HCFC? - correct Answers-Hydrochlorofluorocarbons.
Which refrigerants are HCFC's? - correct Answers-R-22,123.
Which is more harmful to the ozone layer a CFC or an HCFC? - correct Answers-CFC's.
What is it about CFC's that make them more harmful to the stratosphere? - correct
Answers-Chemical strength, they will not breakdown in the lower atmosphere.
What is an HFC? - correct Answers-A fluorocarbon that contains no chlorine.
Which refrigerants are HFC's? - correct Answers-R-134a,404a,407c,410a.
What is the ODP of the HFC refrigerant? - correct Answers-Zero.
Which refrigerants contain chlorine? - correct Answers-CFC's and HCFC's.
Which refrigerants have high ODP? - correct Answers-CFC's.
Which refrigerants have low ODP? - correct Answers-HCFC's, HFC's are zero.
What is an azeotrope refrigerant? - correct Answers-A mixture of two or more
compounds where the mixture behaves like a single chemical.
Is one of the components of R-500 a CFC? - correct Answers-Yes
Does stratospheric ozone help or hurt the work of the earth's protective shield? - correct
Answers-It helps.
What chemical in the stratosphere tells us ozone depletion is occurring? - correct
Answers-Chlorine-monoxide.
Exam
What are the typical uses of the center port of gauge set? - correct Answers-Used
during evacuation, charging and recovery procedures.
What color are the gauges on a manifold gauge set? - correct Answers-Low pressure is
blue, High pressure is red.
What are the typical ranges of pressure measurements used on the gauges of a
manifold gauge set? - correct Answers-High side is 0 to 500 PSIG; Low side is 0 to 350
PSIG and 0 to 30 in. Hg below atmospheric pressure.
Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas? -
correct Answers-High pressure, liquid.
Is the refrigerant entering the expansion valve (variable metering device) a liquid or
gas? - correct Answers-Liquid, high pressure.
Is the pressure of the refrigerant entering the compressor high or low? - correct
Answers-Low pressure vapor.
Where in a refrigerant circuit does a liquid boil to absorb heat? - correct Answers-In the
evaporator.
The refrigerant in the suction line is a gas that has been heated above its saturation.
What is this condition called? - correct Answers-Superheated vapor.
What can cause liquid refrigerant to migrate to a compressor crankcase? - correct
Answers-If the compressor is located in the coldest location in the circuit.
List two conditions that can quickly damage a compressor that is starting to run? -
correct Answers-Operating while in a deep vacuum or when the service valves are
closed.
What system failures require taking an oil sample? - correct Answers-A compressor
burnout or if the unit has had a leak.
Is flushing with refrigerant an acceptable tube cleaning method? - correct Answers-No.
,In addition to preventing and repairing leaks what else should a technician do to
conserve refrigerant? - correct Answers-Recover and recycle used refrigerants.
What factors affect the speed of an evacuation? - correct Answers-Pump size, hose
length, hose diameter, size of system to be evacuated, ambient temperature, suction
line size, and the amount of moisture in the system.
How should gauge set hoses be sized for use in evacuating a system? - correct
Answers-Use the shortest length and the largest diameter possible for the quickest
evacuation. At least as large as the vacuum pump inlet.
When evacuating what is the benefit of using short hoses with large diameters? -
correct Answers-Reduces emissions, pressure drop and evacuation time.
Which connection determines the preferred size of hoses used with a vacuum pump? -
correct Answers-The vacuum pump inlet.
As the capacity and suction hose size increase what happens to the time needed for an
evacuation? - correct Answers-Time is reduced.
What purpose is served by heating a system during dehydration? - correct Answers-To
speed up moisture removal.
Does a thorough evacuation remove moisture from a system? - correct Answers-Yes.
What can happen to oil in the compressor if the moisture is left in an operating system?
- correct Answers-The oil will form hydrofluoric and hydrochloric acids which will corrode
the internal parts of the system.
What is the result of over-evacuating a system? - correct Answers-No damage will be
done.
How can a system be leak checked using a low pressure gauge? - correct Answers-
Vacuum reading will rise when vacuum pump is turned off.
How close should the vacuum gauge be connected to the vacuum pump during
evacuation? - correct Answers-As far away as possible.
When measuring the vacuum of a system being evacuated the system must be isolated.
What must be done to the vacuum pump? - correct Answers-Turn it off and valve it off.
What is ozone? - correct Answers-3 atoms of oxygen. It blocks much of the harmful
ultraviolet radiation (uv-b) emitted from the sun and it keeps our earth's temperature
stable.
, How much ozone can a chlorine atom destroy in the stratosphere? - correct Answers-
One atom can destroy 100,000 ozone molecules.
What is Ozone Depletion Potential (ODP)? - correct Answers-The ability of any
chemical to deplete the ozone layer.
What is CFC? - correct Answers-Chlorofluorocarbon.
Which refrigerants are CFC's? - correct Answers-R-11,12,113,114.
Which chemical in the CFC refrigerants does the most damage to the ozone layer? -
correct Answers-Chlorine.
What is an HCFC? - correct Answers-Hydrochlorofluorocarbons.
Which refrigerants are HCFC's? - correct Answers-R-22,123.
Which is more harmful to the ozone layer a CFC or an HCFC? - correct Answers-CFC's.
What is it about CFC's that make them more harmful to the stratosphere? - correct
Answers-Chemical strength, they will not breakdown in the lower atmosphere.
What is an HFC? - correct Answers-A fluorocarbon that contains no chlorine.
Which refrigerants are HFC's? - correct Answers-R-134a,404a,407c,410a.
What is the ODP of the HFC refrigerant? - correct Answers-Zero.
Which refrigerants contain chlorine? - correct Answers-CFC's and HCFC's.
Which refrigerants have high ODP? - correct Answers-CFC's.
Which refrigerants have low ODP? - correct Answers-HCFC's, HFC's are zero.
What is an azeotrope refrigerant? - correct Answers-A mixture of two or more
compounds where the mixture behaves like a single chemical.
Is one of the components of R-500 a CFC? - correct Answers-Yes
Does stratospheric ozone help or hurt the work of the earth's protective shield? - correct
Answers-It helps.
What chemical in the stratosphere tells us ozone depletion is occurring? - correct
Answers-Chlorine-monoxide.
