R410a Certification Exam With Questions and Verified Answers

R410a Certification Exam With Questions and Verified Answers Recovery cylinders used with R410 must have a DOT rating of: - ANSWER * DOT 4BA 400 * DOT 4BW 400 A system using R410 refrigerant has bubbles in the sight glass. Technicia n A says that the system must be low on refrigerant. Technician B says that the bubb les could be caused by the blended refrigerant flashing in the increased volume of th e sightless. Who is right? - ANSWER Technician B only When charging an R410a system that uses a thermostatic expansion valve, proper charge can be determined by measuring: - ANSWER Subcooling When charging an R410a system that uses a capillary tube or a fixed metering device, proper charge can be determined by measuring: - ANSWER Superheat Compressor internal pressure relief settings for R410a systems are: - ANSWER 550 psig to 625 psig When handling refrigerants technicians should: - ANSWER Wear approve d eye protection and gloves R410a systems use a high pressure switch that will open at approximately: - ANSWER 610 psig plus or minus 10 psig Subcooled liquid in the receiver may _____ subcooling, deoending on surrounding conditions. - ANSWER Lose or gain When installing a liquid line filter drier on a R410a system, be certain that it has a pressure rating of at least: - ANSWER 600 psig The flow area of a R410a metering device is: - ANSWER Smaller than that of a r22 metering device Which of the following statements is true of R407C? - ANSWER It may separate (fractionate) into its component refrigerants A true azeotropic blend: - ANSWER * Will not fractionate * Has no temperature glide * Behaves as a single component refrigerant When a blend is zeotropic, or near-azeotropic (NARM): - ANSWER * Leaks may cause a change in composition of the blend * It will have a temperature glide * It can fractionate R410a is also known as: - ANSWER * Suva 410A * AZ- 20 * Puron The temperature glide for R410a is less than _____ degrees Farenheit over air conditioning and refrigerating operating ranges: - ANSWER 0.3 Polyol Ester (POE) - ANSWER Can be irritating to the skin, is hygroscopic, has improved heat transfer characteristics over mineral oils The low pressure control on R410a systems will open at: - ANSWER 50 psig Compressor ratio is calculated as: - ANSWER Absolute discharge pressu re divided by absolute suction pressure Both suction and discharge pressures of R410a systems are _____ than R22 systems. - ANSWER 40% to 70% higher Because of its higher vapor heat capacity, the discharge temperature of R410a is _____ than R22. - ANSWER Lower