EPA 608 TYPE III PRACTICE QUESTIONS AND
ANSWERS
A) 2 psig.
B) 5 psig.
C) 10 psig.
D) 15 psig.
Answer: C - answerA 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) adding compressed air, since it will be removed from the system by the Purging unit.
B) operating the purge system.
C) adding HCFC-22.
D) raising system pressure by heating with circulated hot water or heating blankets.
Answer: D - answerA charged low pressure refrigeration system can be efficiently leak
checked by:
A) low head pressure.
B) low suction pressure.
C) high head pressure.
D) high liquid level.
Answer: C - answerThe existence of air in a low pressure system, causes __________.
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
Answer: D - answerWhich safety precaution should be adhered to for low pressure systems?
A) 60.3F.
B) 74.5F.
C) 79.7F.
D) 80.2F.
Answer: B - answerRefrigerant-11 at 14.7 PSIA will boil at about:
A) the system was charged with contaminated refrigerant.
B) the condenser or chiller barrel tubes are leaking.
C) the purge unit is not operating properly.
D) the purge unit needs adjustment.
Answer: B - answerWhen there is excessive moisture collecting in the purge unit of a low
pressure refrigeration system, this indicates that the __________.
A) A1
B) B2
C) A2
D) All refrigerant safety groups
Answer: D - answerASHRAE Standard 15 - 1994 requires equipment room refrigerant sensors
for what safety group classification?
A) 21.1" Hg vacuum
B) 19.7" Hg vacuum
C) 18.1" Hg vacuum
D) 16.9" Hg vacuum
, Answer: D - answerWhen recharging a refrigeration system with R-11, what vapor pressure
is necessary in the shells before charging with liquid?
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.
Answer: B - answerAfter reaching the required recovery vacuum on a chiller, you should:
A) blow all water from the tubes.
B) remove any water from the machine.
C) vent refrigerant.
D) determine if a tube leaks.
Answer: D - answerA hydrostatic tube test kit is used to:
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 cause the refrigerant to boil and may lower
temperatures enough to freeze the water in the tubes.
Answer: D - answerWhen charging a chiller, refrigerant vapor is introduced into the system
before charging with liquid. This is because:
A) trapped water to freeze.
B) trapped oil to freeze.
C) trapped refrigerant to freeze.
D) valves to freeze.
Answer: A - answerWhen evacuating a system, the use of too large a vacuum pump can
cause:
A) chiller tubes
B) shaft seal
C) charging connections
D) shaft bearings
Answer: B - answerOn a low-pressure chiller with an open-type compressor, the
________________ is very susceptible to leaks.
A) Leave the purge unit on-line at all times.
B) System pressure should be maintained slightly above atmospheric.
C) Open the air vents on the condenser.
D) Intermittently operate the system with no load.
Answer: B - answerWhat steps may be taken to prevent air accumulation into an idle low
pressure refrigeration system?
A) 5%
B) 15%
C) 20%
D) 35%
Answer: D - answerCommercial and industrial process refrigeration systems must be
repaired when the leak rate exceeds ______ percent of the charge per
year.
A) water pumps should be on, and the recovery compressor should be off.
ANSWERS
A) 2 psig.
B) 5 psig.
C) 10 psig.
D) 15 psig.
Answer: C - answerA 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) adding compressed air, since it will be removed from the system by the Purging unit.
B) operating the purge system.
C) adding HCFC-22.
D) raising system pressure by heating with circulated hot water or heating blankets.
Answer: D - answerA charged low pressure refrigeration system can be efficiently leak
checked by:
A) low head pressure.
B) low suction pressure.
C) high head pressure.
D) high liquid level.
Answer: C - answerThe existence of air in a low pressure system, causes __________.
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
Answer: D - answerWhich safety precaution should be adhered to for low pressure systems?
A) 60.3F.
B) 74.5F.
C) 79.7F.
D) 80.2F.
Answer: B - answerRefrigerant-11 at 14.7 PSIA will boil at about:
A) the system was charged with contaminated refrigerant.
B) the condenser or chiller barrel tubes are leaking.
C) the purge unit is not operating properly.
D) the purge unit needs adjustment.
Answer: B - answerWhen there is excessive moisture collecting in the purge unit of a low
pressure refrigeration system, this indicates that the __________.
A) A1
B) B2
C) A2
D) All refrigerant safety groups
Answer: D - answerASHRAE Standard 15 - 1994 requires equipment room refrigerant sensors
for what safety group classification?
A) 21.1" Hg vacuum
B) 19.7" Hg vacuum
C) 18.1" Hg vacuum
D) 16.9" Hg vacuum
, Answer: D - answerWhen recharging a refrigeration system with R-11, what vapor pressure
is necessary in the shells before charging with liquid?
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.
Answer: B - answerAfter reaching the required recovery vacuum on a chiller, you should:
A) blow all water from the tubes.
B) remove any water from the machine.
C) vent refrigerant.
D) determine if a tube leaks.
Answer: D - answerA hydrostatic tube test kit is used to:
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 cause the refrigerant to boil and may lower
temperatures enough to freeze the water in the tubes.
Answer: D - answerWhen charging a chiller, refrigerant vapor is introduced into the system
before charging with liquid. This is because:
A) trapped water to freeze.
B) trapped oil to freeze.
C) trapped refrigerant to freeze.
D) valves to freeze.
Answer: A - answerWhen evacuating a system, the use of too large a vacuum pump can
cause:
A) chiller tubes
B) shaft seal
C) charging connections
D) shaft bearings
Answer: B - answerOn a low-pressure chiller with an open-type compressor, the
________________ is very susceptible to leaks.
A) Leave the purge unit on-line at all times.
B) System pressure should be maintained slightly above atmospheric.
C) Open the air vents on the condenser.
D) Intermittently operate the system with no load.
Answer: B - answerWhat steps may be taken to prevent air accumulation into an idle low
pressure refrigeration system?
A) 5%
B) 15%
C) 20%
D) 35%
Answer: D - answerCommercial and industrial process refrigeration systems must be
repaired when the leak rate exceeds ______ percent of the charge per
year.
A) water pumps should be on, and the recovery compressor should be off.
