ACTUAL Exam Questions and CORRECT
Answers
Recovery cylinders used with R-410A must have a DOT rating of: - CORRECT
ANSWER - either "DOT 4BA 400" or "DOT 4BW 400"
A system using R-410A refrigerant has bubbles in the sight glass. Technician A says that the
system must be low on refrigerant. Technician B says that the bubbles could be caused by the
blended refrigerant flashing in the increased volume of the sight glass. Who is correct? -
CORRECT ANSWER - Technician B only
When charging a R-410A system that uses a thermostatic expansion valve, proper charge can be
determined by measuring - CORRECT ANSWER - Subcooling
When charging a R-410A system that uses a capillary tube or fix metering device, proper charge
can be determined by measuring - CORRECT ANSWER - Superheat
Compressor internal pressure relief (IPR) settings for R-410A systems are: - CORRECT
ANSWER - 550 psig to 625 psig
When handling refrigerants, technicians should: - CORRECT ANSWER - Where approved
eye protection and gloves
R-410A systems use a high pressure switch that will open at approximately: - CORRECT
ANSWER - 610 psig plus or minus 10 psig
Subcooled liquid in the receiver may ______________ subcooling, depending on surrounding
conditions. - CORRECT ANSWER - either "lose" or "gain"
, When installing a liquid line filter dryer on a R-410A system, be certain that it has a pressure
rating of at least: - CORRECT ANSWER - 600 pisg
The flow area of a R-410A metering device is: - CORRECT ANSWER - Smaller than that
of a R-22 metering device
Which of the following statements is true of R-407C - CORRECT ANSWER - It may
separate (fractionate) into its component refrigerants
A true Azeotropic blend - CORRECT ANSWER - Has no temperature glide, will not
fractionate, and behaves as a single component refrigerant
When a blend is zeotropic, or near-azeotropic (NARM), - CORRECT ANSWER - It will
have temperature glide, it can fractionate, and leaks may cause a change in composition of the
bland
R-410A is also known as - CORRECT ANSWER - Suva 410A, AZ-20, and Puron
The temperature glide for R-410A is less than _____________ degrees Fahrenheit over air
conditioning and refrigerating operating ranges. - CORRECT ANSWER - 0.3
Polyol Ester (POE) - CORRECT ANSWER - Is hygroscopic, can be irritating to the skin,
and has improved heat transfer characteristics over mineral oils
The low pressure control on R-410A system will open at: - CORRECT ANSWER - 50
pisg
Compression ratio is calculated as: - CORRECT ANSWER - Absolute discharge pressure
divided by absolute suction pressure