R 410A TEST PAPER QUESTIONS AND
SOLUTIONS COMPLETE REVIEW MATERIAL
●● What are the different brand names of R-410A listed in the book?
Answer: Is presently marked under brand names AZ-20, "Puron", or "
Suva".
●● What oil does R-410A use?
Answer: R-410A utilizes Polyol Ester (POE) based oils.
●● How is compression ratio calculated?
Answer: Compression Ratio = absolute discharge pressure (divided)
absolute suction pressure
●● Is there a difference in operation pressures between R-410A and R-
22? If so, what is the percentage difference?
Answer: Yes, both high and low side operation pressure are
approximately 50%-70% higher for R-410A systems when compared to
R-22 systems.
●● How have manufacturers changed the design of their compressors to
be compatible with R-410A
operating pressures?
, Answer: Manufacturers have redesigned their compressors with
increased wall thickness due to higher pressure associated with R-410A
●● What is the internal pressure relief (IPR) rated for compressors used
with R-410A?
Answer: The IPR will open at a pressure of... 550-625 psig for R-410A
systems.
●● Why is the discharge temperature of R-410A lower than that of R-
22?
Answer: The discharge temperature of R-410A is lower due to its higher
vapor heat capacity
Vapor heat capacity just means how much heat the refrigerant absorbs
before changing sensible temperature
●● At what pressure will the high-pressure control open, on an R-410A
system?
Answer: The high pressure switch will... open at 610 psig plus or minus
10 psig
●● At what pressure will the low-pressure control open, on an R-410A
system?
Answer: The low pressure control will open at 50 psig
SOLUTIONS COMPLETE REVIEW MATERIAL
●● What are the different brand names of R-410A listed in the book?
Answer: Is presently marked under brand names AZ-20, "Puron", or "
Suva".
●● What oil does R-410A use?
Answer: R-410A utilizes Polyol Ester (POE) based oils.
●● How is compression ratio calculated?
Answer: Compression Ratio = absolute discharge pressure (divided)
absolute suction pressure
●● Is there a difference in operation pressures between R-410A and R-
22? If so, what is the percentage difference?
Answer: Yes, both high and low side operation pressure are
approximately 50%-70% higher for R-410A systems when compared to
R-22 systems.
●● How have manufacturers changed the design of their compressors to
be compatible with R-410A
operating pressures?
, Answer: Manufacturers have redesigned their compressors with
increased wall thickness due to higher pressure associated with R-410A
●● What is the internal pressure relief (IPR) rated for compressors used
with R-410A?
Answer: The IPR will open at a pressure of... 550-625 psig for R-410A
systems.
●● Why is the discharge temperature of R-410A lower than that of R-
22?
Answer: The discharge temperature of R-410A is lower due to its higher
vapor heat capacity
Vapor heat capacity just means how much heat the refrigerant absorbs
before changing sensible temperature
●● At what pressure will the high-pressure control open, on an R-410A
system?
Answer: The high pressure switch will... open at 610 psig plus or minus
10 psig
●● At what pressure will the low-pressure control open, on an R-410A
system?
Answer: The low pressure control will open at 50 psig
