NATE Industry Competency Exam: Commercial Refrigeration | 100 Questions with 100% Correct Answers

With the condensing pressure and compressor speed remaining constant, a decrease in suction pressure will cause a(n): a. Decrease in compressor capacity and decrease in current. b. Increase in compressor capacity and decrease in current. c. Increase in compressor capacity and increase in current. d. Decrease in compressor capacity and increase in current. - D An indication of non-condensable gas in a refrigeration system is significantly: a. Lower-than-normal suction pressures. b. higher-than-normal suction pressures. c. Lower-than-normal head pressures. d. higher-than-normal head pressures. - D An automatic expansion valve controls refrigerant flow to an evaporator by maintaining a constant: a. Suction pressure. b. Pressure differential across the valve port. c. Liquid line pressure. d. Superheat. - A What is the approximate compression ratio of a compressor operating at 35 psig suction pressure and 135 psig discharge pressure? a. 1:03. b. 3:01. c. 1:04. d. 4:01. - B