Questions and answers 2024\2025 A+
Grade
Where do leaks commonly occur in low pressure systems?
a. Evaporator
b. Condenser
c. Purge unit
d. Gaskets or fittings
- correct answer d. Gaskets or fittings
Where do leaks commonly occur in open-drive type compressor systems?
a. Evaporator
b. Condenser
c. Shaft seal
d. Cooling tower
- correct answer c. Shaft seal
Does refrigerant go out of the system in low pressure systems or does air and
moisture go in?
a. Refrigerant escapes through low pressure leaks.
b. Air and moisture enter the refrigeration system because it operates
in a vacuum
c. Refrigerant leaks out through shaft seals and gaskets.
- correct answer b. Air and moisture enter the refrigeration system because it operates
in a vacuum
, When should a low pressure system be leak checked according to ASHRAE
guideline 3-1996?
a. There are specific recommendations.
b. During pressure checks
c. When the system rises from 1 mm Hg to a level above 2.5 mm Hg
during vacuum testing
d. Leak check every year
- correct answer c. When the system rises from 1 mm Hg to a level above 2.5 mm Hg during vacuum
testing
What does a purge unit do and what is a high efficiency purge unit?
a. Removes the refrigerant from the system. High efficiency purge system
will expel large quantities of refrigerant
b. Removes the refrigerant from the system. High efficiency purge system
will expel very little refrigerant
c. Removes the oil from the system. High efficiency purge system will expel
very little refrigerant
d. Removes the air from the system. High efficiency purge system will
expel very little refrigerant
- correct answer d. Removes the air from the system. High efficiency purge system will
expel very little refrigerant
How does a centrifugal compressor purge unit work?
a. Takes its suction from the top of the evaporator, removes the air from the
system, and returns the refrigerant to the evaporator
b. Takes its suction from the top of the chiller barrel, removes the air from the
system, and returns the refrigerant to the evaporator
c. Takes its suction from the top of the compressor suction, removes the air
from the system, and returns the refrigerant to the evaporator