1. Section 608 Certification Pre-Test
Mr. Morgan
HVAC/R Instructor

2. Before you dispose of any appliance containing a CFC or HCFC refrigerant, you must;
A: recover the refrigerant.
B: purge the appliance with nitrogen.
C: flush the appliance with R-11.
D: seal the appliance so no refrigerant can escape.

3. HCFC refrigerants are;
A: more harmful to stratospheric ozone than CFCs.
B: as harmful to stratospheric ozone as CFCs.
C: less harmful to stratospheric ozone than CFCs.
D: not harmful to stratospheric ozone.

4. An award of up to what amount may be paid to a person supplying information that leads to a penalty against a technician who is intentionally venting?
A: $5,000.
B: $10,000.
C: $25,000.
D: $50,000.

5. Ozone in the stratosphere above the earth consists of;
A: molecules containing 3 oxygen atoms.
B: molecules of 2 oxygen atoms.
C: radioactive particles.
D: pollutants that have risen from ground level.

6. Which compounds have the highest ozone depletion potential (ODP)?
A: HCFCs.
B: HFCs.
C: CFCs.
D: All are equal.

7. Each chlorine atom in the stratosphere can destroy ______ ozone molecules.
B: 3
C: 100,000
D: Chlorine is not the element in refrigerant that harms ozone.

8. Service technicians who violate Clean Air Act provisions:
A: May be fined.
B: May lose certification.
C: May be required to appear in Federal court.
D: All of the above.

9. What effects can ozone depletion have on the environment?
A: Reduced crop yields.
B: Reduced marine life.
C: Increased ground-level ozone.
D: All of the above.

10. Which of the following CFC or HCFC refrigerant releases is considered a violation of the prohibition on venting?
A: Release of "de minimis" quantities in the course of making good faith attempts to recapture and recycle or safely dispose of refrigerant.
B: Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to leak-check the appliance.
C: Refrigerants emitted in the course of normal operation of an appliance.
D: Refrigerants emitted when connecting or disconnecting hoses to charge or service an appliance.

11. What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
A: CFCs neither dissolve in water nor break down into compounds that dissolve in water, so they do not rain out of the atmosphere.
B: CFCs are lighter than other chlorine compounds, making it easier for them to float upward when released.
C: CFCs are stored under pressure, causing them to jet upward when released.
D: CFCs are attracted to ultraviolet radiation.

12. The Clean Air Act; A: calls for the phase out of CFC/HCFC production.
B: prohibits venting of CFC and HCFC refrigerants and their substitutes.
C: requires EPA to set standards for recovery of refrigerants prior to appliance disposal.
D: All of the above.

13. Which atom of the CFC molecule causes ozone depletion?
A: Fluorine.
B: Chlorine.
C: Carbon.
D: Hydrogen.

14. A: green. B: yellow. C: blue. D: red.
Manufacturers often color code the exterior of gauges. On a typical gauge manifold set, the high pressure gauge is color coded;
A: green.
B: yellow.
C: blue.
D: red.

15. If a system will not hold a vacuum after it has been evacuated, then;
A: the system is ready to be charged.
B: the system has been adequately evacuated.
C: the system may be leaking.
D: an expansion valve is clogged.

16. The piping connection to the vacuum pump should be;
A: as short in length and as large in diameter as possible.
B: suitably sized to connect to a gauge manifold.
C: coiled and taped together.
D: colored red or blue to meet codes.

17. Refrigerant entering the compressor of a refrigeration system is a;
A: liquid
B: sub-cooled liquid
C: sub-cooled vapor
D: superheated vapor

18. A: HFC-134a. B: HFC-125. C: CFC-502. D: None of the above.
Which of the following is an approved "drop-in" service replacement for R-12?
A: HFC-134a.
B: HFC-125.
C: CFC-502.
D: None of the above.

19. Some state and local governments may establish laws that;
A: follow the Clean Air Act/EPA regulations.
B: are not as strict as the Clean Air Act/EPA regulations.
C: contain stricter regulations than the Clean Air Act / EPA regulations.
D: Both "A" and "C".

20. How should refrigerant cylinders be positioned when they are shipped?
A: Inverted.
B: Upright.
C: Horizontally.
D: Stacked.

21. A: They have the same ozone depletion potential.
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) have which of the following in common?
A: They have the same ozone depletion potential.
B: They both contain hydrogen.
C: They must be. recovered before opening or disposing of appliances.
D: They have the same saturation pressure at 70°F

22. A: When the system contains the same refrigerant as the cylinder.
Under what conditions may you use a disposable cylinder to recover refrigerant?
A: When the system contains the same refrigerant as the cylinder.
B: When the system contains less than 10 lbs. of refrigerant.
C: Only in an emergency.
D: Never.

23. Why shouldn't technicians use oxygen or compressed air to pressurize appliances to check for leaks?
A: When mixed with compressor oil or some refrigerants, either oxygen or compressed air can cause an explosion.
B: Leaking oxygen or compressed air is difficult to detect.
C: The pressures produced by either oxygen or compressed air are not acceptable.
D: Neither oxygen nor compressed air mix well with refrigerants.

24. D: All oils are compatible with HFC-134a.
The oils that will be employed with most of the HFC-134a refrigeration applications are;
A: esters.
B: alkylbenzenes.
C: whale oils.
D: All oils are compatible with HFC-134a.

25. A: excessive pressure drop. B: increased recovery time.
Long hoses between the unit and the recovery machine should be avoided as they cause;
A: excessive pressure drop.
B: increased recovery time.
C: increased emissions.
D: All of the above.

26. A: recycling. B: recovering. C: reclaiming. D: restoring.
Removing refrigerant in any condition from a system and storing it in an external container without necessarily testing or processing it in any way defines;
A: recycling.
B: recovering.
C: reclaiming.
D: restoring.

27. TYPE I

28. A: When there is a leak in the system.
Using the system-dependent (passive) recovery process, which condition requires the accessing both the high and low side of the system for refrigerant recovery?
A: When there is a leak in the system.
B: When the compressor operates normally.
C: When the compressor only runs at half speed.
D: When the compressor does not run.

29. When R-500 is recovered from an appliance, it;
A: can be mixed with either R-22 or R-12 during the recovery process, since R-500 is actually a mixture of the two refrigerants.
B: can be mixed with R-12 but not R-22 during the recovery process.
C: need not be recovered since R-500 is not one of the refrigerants covered by the Clean Air Act.
D: must be recovered into its own recovery vessel that is clearly marked to ensure that mixing of refrigerants does not occur.

30. Recovery equipment used during maintenance, service or repair of small appliances must be certified by an EPA-approved laboratory if manufactured AFTER:
A: July 1, 1992.
B: July 1, 1993.
C: May 13, 1993.
D: November 15, 1993.

31. A: To prevent safety valves from purging refrigerant.
When checking for non-condensables inside a recovery cylinder, why should the technician allow the temperature of the cylinder to stabilize to room temperature before taking a pressure reading?
A: To prevent safety valves from purging refrigerant.
B: It is a quick method of determining refrigerant level inside the tank.
C: Comparisons to a pressure-temperature chart are only valid if both the pressure and temperature of the refrigerant are stable and known.
D: A temperature reading alone is enough to determine refrigerant quality.

32. A: be used alone as a self-contained (active) recovery device.
A standard vacuum pump designed specifically for evacuation and dehydration can;
A: be used alone as a self-contained (active) recovery device.
B: never be used as a recovery device in combination with a pressurized container.
C: be used alone as a substitute for any recovery device.
D: be used alone as a system-dependent (passive) recovery device.

33. When servicing a small appliance for leak repair;
A: It is mandatory to repair the leak within days.
B: It is mandatory to repair the leak only when 35% of the charge escapes within a 12 month period.
C: It is not mandatory to repair the leak but do so whenever possible.
D: Both "A" and "B".

34. When recovering refrigerant into a non-pressurized container from a refrigerator with an in operative compressor;
A: It is necessary to heat the compressor and strike it with a rubber mallet.
B: It is only necessary to recover as much refrigerant as will naturally flow out of the system.
C: It is not necessary to recover since the refrigerant is probably contaminated.
D: It is necessary to chase refrigerant from the oil with pressurized dry nitrogen.

35. A: a system-dependent (passive) process.
EPA rules require capture of 80% of the refrigerant from a small appliance sealed system with a non-operating compressor if technicians are using;
A: a system-dependent (passive) process.
B: a self-contained (active) process.
C: Either recovery process.
D: Neither recovery process.

36. When installing any type of access fitting onto a sealed system;
A: the fitting should be leak tested before proceeding with recovery.
B: it is not necessary to leak test an access fitting.
C: the fitting need not be leak tested until the total repair is completed.
D: the system must be pressurized with dry nitrogen before leak testing can be attempted.

37. Which of the following is NOT a Type I appliance?
A: An MVAC-like system that holds three pounds of R-12.
B: A water cooler that holds 13 ounces of R-12.
C: A food freezer that holds 22 ounces of R-22.
D: A dehumidifier with seven ounces of R-500.

38. B: Products having 5 pounds or less of refrigerant.
EPA regulations include which of the following in the definition of a "small appliance"?
A: Products manufactured, charged and hermetically sealed in a factory.
B: Products having 5 pounds or less of refrigerant.
C: Products with compressors under 1/2 horsepower.
D: Both "A" and "B".

39. If EPA regulations change after a technician becomes certified;
A: the technician certification is "grand fathered" for one year to allow time for re-certification.
B: it will be the technician's responsibility to comply with any future changes in the law.
C: a new certification test must be taken to be re-certified.
D: Both "A" and "C".

40. The sale of CFC and HCFC refrigerants is
A: banned.
B: limited by law to equipment owners.
C: allowed only if there is proof of need.
D: restricted to technicians who are PA certified in refrigerant recovery.

41. A: 250 psig. B: 200 psig. C: 175 psig. D: 130 psig.
A storage cylinder of recovered R-22 at normal room temperature (about 75 degrees F), in the absence of non-condensables, will be pressurized to;
A: psig.
B: psig.
C: psig.
D: psig.

42. A: allow the appliance to stabilize at room temperature.
Before beginning a refrigerant recovery procedure it is ALWAYS necessary to;
A: allow the appliance to stabilize at room temperature.
B: know the type of refrigerant that is in the system.
C: remove the appliance to an outdoor location.
D: disconnect the appliance from its power source.

43. The system-dependent (passive) recovery process for small appliances;
A: never needs the use of a pump or heat to recover refrigerant.
B: must use a pressure relief device when recovering refrigerant.
C: captures refrigerant in a non-pressurized container.
D: can only be performed on a system with an operating compressor.

44. A: Copper B: Aluminum C: Steel D: Both "A" and "B"
It is generally recommended that piercing-type valves be used on which of the following tubing materials?
A: Copper
B: Aluminum
C: Steel
D: Both "A" and "B"

45. C: resell the refrigerant for reuse in its current state.
If a reclamation facility receives a tank of mixed refrigerant, they may;
A: refuse to process the refrigerant and return it at the owner's expense.
B: agree to destroy the refrigerant, but typically a substantial fee is charged.
C: resell the refrigerant for reuse in its current state.
D: Both "A" and "B".

46. A: Use butyl lined gloves and try to stop the leak.
If a large leak of refrigerant occurs such as from a filled cylinder in an enclosed area, what action should be taken when no self-contained breathing apparatus is available?
A: Use butyl lined gloves and try to stop the leak.
B: Use a leak detector to locate the leak and try to stop the leak.
C: Vacate and ventilate the spill area.
D: All of the above.

47. A: 30 psig. B: 75 psig. C: 95 psig. D: 120 psig.
A storage cylinder of recovered R-500 at normal room temperature (about 75 degrees F), in the absence of nun-condensables, will be pressurized to;
A: psig.
B: psig.
C: psig.
D: psig.

48. A: it can enhance the speed of recovery.
When a household refrigerator compressor does not run, it is recommended that low and high side access valves be installed when recovering refrigerant from the system because;
A: it can enhance the speed of recovery.
B: it may be necessary to achieve required recovery efficiency.
C: otherwise, the refrigerator's compressor may be damaged.
D: Both "A" and "B".

49. A: they smell strong and make breathing difficult.
Refrigerants (i.e., R-12, R-22, R-500, etc.) in large quantities can cause suffocation because;
A: they smell strong and make breathing difficult.
B: they are lighter than air and cause dizziness.
C: they are heavier than air and displace oxygen.
D: they sting the nose and cause sneezing.

50. A: Department of Transportation. B: Community Right-To-Know Act.
Portable refillable tanks or containers used to ship CFC or HCFC refrigerants obtained with recovery equipment must meet what standard (s)?
A: Department of Transportation.
B: Community Right-To-Know Act.
C: Underwriters Laboratories.
D: All of the above.

51. A: hydrozine gas. B: phosgene gas. C: helium gas.
At high temperatures, (i.e., open flames, glowing metal surfaces, etc.) R-12 and R-22 can decompose to form;
A: hydrozine gas.
B: phosgene gas.
C: helium gas.
D: None of the above.

52. A: need not be recovered. B: must be recovered.
When filling a graduated charging cylinder, refrigerant that is vented off the top of the cylinder;
A: need not be recovered.
B: must be recovered.
C: is considered a "de minimis" release.
D: None of the above.

53. TYPE II

54. A: Nothing, as long as the recovery machine is not full.
Your recovery/recycling machine has R-502 refrigerant in it. You now have to recover refrigerant from a unit with R-22. What must be done before the R-22 refrigerant can be recovered/recycled?
A: Nothing, as long as the recovery machine is not full.
B: Change the expansion valve on the recovery machine.
C: Change the filter and expansion valve on the recovery machine.
D: Recover as much of the R-502 from the recovery unit as possible, change filter, and evacuate.

55. A: It runs faster than other equipment.
Recycling or recovery equipment using hermetic compressors has the potential to overheat when drawing deep vacuums because;
A: It runs faster than other equipment.
B: the motor relies on the flow of refrigerant through the compressor for cooling.
C: it has a higher compression ratio limit than other equipment.
D: the oils used in hermetic compressors burn at lower temperatures than the oils used in other equipment.

56. A: The suction service valve. B: The rotating shaft seal.
Many refrigeration units use an open compressor. Which part of the compressor is most likely to leak if a unit is not used for several months?
A: The suction service valve.
B: The rotating shaft seal.
C: The oil drain plug.
D: The discharge service valve.

57. A: It must be tested by an EPA-approved third party.
Which of the following statements is NOT true of recycling and recovery equipment manufactured AFTER November 15, 1993?
A: It must be tested by an EPA-approved third party.
B: It must meet vacuum standards more stringent than those met by equipment manufactured BEFORE November 15, 1993.
C: It must be equipped with low-loss fittings.
D: It must have an oil separator.

58. Refrigerant should be removed from the condenser outlet when;
A: the condenser is below the receiver.
B: the condenser is on the roof.
C: the compressor is inoperative.
D: the evaporator has a small leak.

59. B: pressurized with R-22/leak checked.
After installation of a field-piped split system, the unit should first be;
A: evacuated.
B: pressurized with R-22/leak checked.
C: pressurized with R-12/leak checked.
D: pressurized with nitrogen/leak checked.

60. EPA regulations require that all appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) be repaired when the leak rate exceeds ____ percent of the charge per year.
A: 0
B: 15
C: 25
D: 35

61. A: can probably be charged back into the system.
Refrigerant has been recovered from an air-conditioning system and held in a refillable cylinder, in order to replace the condenser coil. The refrigerant;
A: can probably be charged back into the system.
B: should probably be replaced with R-123.
C: must be reclaimed.
D: must be destroyed.

62. A: Simply remove the compressor.
You are changing out the compressor of a system containing 40 pounds R Your recycling equipment was manufactured AFTER November 15, In addition to isolating the compressor as much as possible, which of the following procedures should you follow?
A: Simply remove the compressor.
B: Evacuate the isolated section of the system to atmospheric pressure, then remove the compressor.
C: Evacuate the isolated section of the system to 10 inches of vacuum and hold. If system pressure does not rise, remove the compressor.
D: Evacuate the isolated section of the system to 15 inches of vacuum and hold. If system pressure does not rise, remove the compressor.

63. A: Filter drier. B: Thermostat. C: Metering device.
If a system is opened for servicing, which of the following should be replaced?
A: Filter drier.
B: Thermostat.
C: Metering device.
D: Crankcase heater.

64. A: 0 psig. B: 4 inches of Hg vacuum. C: 10 inches of Hg vacuum.
When using recovery and recycling equipment manufactured AFTER November 15, 1993, technicians must evacuate an appliance component containing MORE than 200 pounds of CFC-12 to the following level before making a major repair:
A: psig.
B: 4 inches of Hg vacuum.
C: inches of Hg vacuum.
D: inches of Hg vacuum.

65. A: final B: initial C: liquid D: vapor
You can save time recovering the refrigerant from a system by removing as much as possible in the___ phase?
A: final
B: initial
C: liquid
D: vapor

66. Every refrigerating system shall be protected by;
A: a pressure relief device.
B: a properly located stop valve.
C: a low pressure control.
D: a refrigerant receiver.

67. The state of the refrigerant leaving the receiver of a refrigeration system is;
A: low pressure liquid.
B: low pressure vapor.
C: high pressure liquid.
D: high pressure vapor.

68. A: from the vapor line entering the condenser.
With an air-cooled condenser on the roof of a building and the evaporator on the first floor, recovery should first occur;
A: from the vapor line entering the condenser.
B: from the discharge of the compressor.
C: from the liquid line entering the evaporator.
D: on the suction side of the compressor.

69. EPA regulations require that leaking commercial and industrial process refrigeration be repaired when the leak rate exceeds ____ percent of the charge per year.
A: 0
B: 15
C: 25
D: 35

70. After reaching the required recovery vacuum on an appliance, you should;
A: immediately disconnect the recycling or recovery equipment and open the system for service.
B: wait for at least a few minutes to see if the system pressure rises, indicating that there is still refrigerant in liquid form or in the oil.
C: immediately break the vacuum with nitrogen and open the system for service.
D: immediately pressurize the system with nitrogen and perform a leak check.

71. A: Check service valve positions. B: Check recovery unit oil level.
Before using a recovery unit to remove a charge, what steps should be taken?
A: Check service valve positions.
B: Check recovery unit oil level.
C: Evacuate recovery unit / receiver.
D: All of the above.

72. A: 0 psig. B: 4 inches of Hg vacuum. C: 10 inches of Hg vacuum.
When using recovery and recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate an appliance containing 10 pounds of CFC-500 to the following level before disposing of the appliance:
A: 0 psig.
B: 4 inches of Hg vacuum.
C: inches of Hg vacuum.
D: inches of Hg vacuum.

73. A: water. B: oil. C: refrigerant. D: All of the above.
Recovering refrigerant from a system in vapor phase will minimize loss of;
A: water.
B: oil.
C: refrigerant.
D: All of the above.

74. D: the appliance is being disposed.
Appliances containing CFC refrigerants can be evacuated to atmospheric pressure when;
A: the repair is major.
B: the repair is followed by an evacuation of the appliance to the environment.
C: leaks in the appliance make evacuation to the prescribed level unattainable.
D: the appliance is being disposed.

75. A: R-12. B: R-134a. C: R-11. D: All of the above.
For what refrigerant (s) is an equipment room refrigerant monitor required under ASHRAE Standard 15?
A: R-12.
B: R-134a.
C: R-11.
D: All of the above.

76. A: the service valve connection. B: the electrical connections.
Refrigerant cannot be recovered without isolating a parallel compressor system because of;
A: the service valve connection.
B: the electrical connections.
C: an open equalization connection.
D: the thermal bleed connection.

77. A: Replacement of an evaporator coil.
Which of the following repairs would ALWAYS be considered "major" under EPA's regulations?
A: Replacement of an evaporator coil.
B: Replacement of a filter-drier.
C: Replacement of a schraeder valve core.
D: Replacement of a condenser fan motor.

78. A: 2 mm Hg. B: 1 mm Hg. C: 1000 microns. D: 500 microns.
When evacuating a vapor compression system, the vacuum pump should be capable of pulling a vacuum of;
A: 2 mm Hg.
B: 1 mm Hg.
C: microns.
D: microns.

79. TYPE III

80. A: 1.5 mm Hg. B: 2.0 mm Hg. C: 2.5 mm Hg. D: 3.0 mm Hg.
According to ASHRAE Guideline , if the pressure in a system rises from 1 mm Hg to a level above __ during a standing vacuum test, the system should be checked for leaks.
A: mm Hg.
B: mm Hg.
C: mm Hg.
D: mm Hg.

81. A: Recover the vapor refrigerant. B: Pressurize system with nitrogen.
With a low-pressure chiller, what must you do after recovering the liquid refrigerant?
A: Recover the vapor refrigerant.
B: Pressurize system with nitrogen.
C: Remove the oil from the system.
D: Solvent-flush entire system.

82. EPA regulations require that leaking commercial and industrial process refrigeration be repaired when the leak rate exceeds ____ percent of the charge per year.
A: 0
B: 15
C: 25
D: 35

83. B: Through the vent valve. C: Through a test plug.
Where would you place a leak detector probe to check gas leaks into the water box with water removed?
A: At the rupture disc.
B: Through the vent valve.
C: Through a test plug.
D: Through a drain valve.

84. A: Refrigerant saturation temperature increases to 36 degrees F.
How do you determine when enough vapor has entered the refrigeration system before you charge refrigerant liquid?
A: Refrigerant saturation temperature increases to 36 degrees F.
B: Recovery unit liquid level drops.
C: Vapor charge for 15 minutes.
D: Recovery unit pressure drops.

85. A: you can warm your hands on the container.
When removing oil from a low pressure system, the temperature should be 130°F because;
A: you can warm your hands on the container.
B: less refrigerant will be contained in the oil at the higher temperature.
C: warmer oil has a lower viscosity and flows more easily.
D: it shows that the heater is working.

86. A hydrostatic tube test kit will;
A: determine if a tube leaks.
B: blow all water out of tubes.
C: remove water from a machine.
D: vent refrigerant to the atmosphere.

87. R-11 or R-123 system refrigerant removal starts with;
A: vapor removal.
B: liquid removal.
C: vapor & liquid removal.
D: oil separation.

88. D: operating the purge system.
Charged low pressure refrigeration machines may be most efficiently leak checked by;
A: adding dry nitrogen.
B: adding HCFC-22.
C: raising system pressure by heating with circulated hot water or heating blankets.
D: operating the purge system.

89. Why do chillers using CFC-11 and HCFC-123 require purge units?
A: Purge units remove moisture.
B: System operates below atmospheric pressure.
C: Purge units remove refrigerant from oil sump.
D: Purge units remove CFCs from the chiller.

90. A: 2 psig. B: 5 psig. C: 10 psig. D: 15 psig.
A typical setting for the high pressure cut-out control on a recovery unit used for evacuating the refrigerant from a low pressure chiller is;
A: psig.
B: psig.
C: psig.
D: psig.

91. EPA regulations require that all appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) be repaired when the leak rate exceeds ____ percent of the charge per year.
A: 0
B: 15
C: 25
D: 35

92. After system servicing, why is refrigerant vapor re-introduced to the refrigeration system be fore refrigerant liquid?
A: Vapor charging increases pressure slowly, preventing failure of the rupture disk.
B: Vapor charging is faster than liquid charging.
C: Liquid charging is more difficult to control than vapor charging.
D: Liquid charged into a deep vacuum will boil and may lower temperatures enough to freeze water in the tubes.

93. A: 28 degrees F. B: 32 degrees F. C: 36 degrees F. D: 40 degrees F.
Refrigerant-11 at a pressure of 18.1 inches Hg vacuum has a saturation temperature of;
A: degrees F.
B: degrees F.
C: degrees F.
D: degrees F.

94. A: 0 psig. B: 15 inches of Hg vacuum. C: 25 inches of Hg vacuum.
When using recovery and recycling equipment manufactured AFTER November 15, 1993, technicians must evacuate low-pressure appliances to the following level before disposing of the appliance:
A: 0 psig.
B: 15 inches of Hg vacuum.
C: 25 inches of Hg vacuum.
D: 25 mm of Hg absolute.

95. B: Warming the refrigerant. C: Adding compressed air.
Under EPA's regulations, which of the following methods can be used to pressurize an R-11 or R-123 system for the purpose of opening the system for a non-major repair?
A: Adding nitrogen.
B: Warming the refrigerant.
C: Adding compressed air.
D: Adding carbon dioxide.

96. A: Replacement of an evaporator coil.
Which of the following repairs would ALWAYS be considered "major" under EPA's regulations?
A: Replacement of an evaporator coil.
B: Replacement of a filter-drier.
C: Replacement of a switch.
D: Replacement of a purge unit.

97. Appliances need not be evacuated all the way to the prescribed level when;
A: the repair is major.
B: the repair is followed by an evacuation of the appliance to the environment.
C: leaks in the appliance make evacuation to the prescribed level unattainable.
D: the appliance is being disposed.

98. After reaching the required recovery vacuum on an appliance, you should;
A: immediately disconnect the recycling or recovery equipment and open the system for service.
B: wait for at least a few minutes to see if the system pressure rises, indicating that there is still refrigerant in liquid form or in the oil.
C: immediately break the vacuum with nitrogen and open the system for service.
D: immediately pressurize the system with nitrogen and perform a leak check.

99. A: 0 psig. B: 15 inches of Hg vacuum. C: 25 inches of Hg vacuum.
When using recovery or recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate low-pressure appliances to the following level before making a major repair:
A: psig.
B: inches of Hg vacuum.
C: inches of Hg vacuum.
D: mm of Hg absolute.

100. The PRIMARY purpose of a purge unit on a CFC-11 chiller is to;
A: remove CFCs from the system.
B: condense air out of the system.
C: condense water out of the system.
D: remove non-condensables from the system.

101. Under what code group of ASHRAE Standard 34 does R-123 fall?
A: Al.
B: A2.
C: Bl.
D: B2.

102. A: Do not siphon refrigerant by mouth.
Which of the following safety precautions should be adhered to for low pressure systems?
A: Do not siphon refrigerant by mouth.
B: Avoid spilling liquid refrigerant on the skin.
C: Use gloves and safety goggles when working with liquid refrigerant.
D: All of the above.

103. On a centrifugal system, the purge unit takes its suction from the;
A: top of the condenser.
B: compressor oil sump.
C: top of the evaporator.
D: suction elbow.

104. Refrigerant is added to a centrifugal machine through the;
A: float valve.
B: compressor service valve.
C: condenser charging valve.
D: evaporator charging valve.

105. THE END!!!!