Test your basic knowledge |

NATE Air Conditioning Troubleshooting

Subjects : engineering, nate
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. When troubleshooting a split-system air conditioner - it is found that the compressor motor is humming but not starting. Technician A says that it could be an open internal overload protector. Technician B says that it could be a blown fuse. Which te






2. Which of the following can cause excessive subcooling...






3. What types of symptoms will be present if the sensing bulb of a TXV is not properly connected...






4. The internal overload of an air conditioning compressor senses winding temperature and...






5. If a TXV sensing bulb had lost its charge - what effect would this have on the air conditioning system...






6. What are common methods that are used for leak-testing a system...






7. What are two common problems that can cause a sight glass in an air conditioning to have bubbles...






8. Which of the following is a common cause of an excessively low superheat on a TXV system...






9. Which of the following can cause excessive subcooling...






10. Technician A says that to manually pump down an air conditioning system with a two-position service valve - the liquid line must be front-seated and the high- and low-side pressure will decrease to 0 psig when the pump-down is complete. Technician B






11. A customer who owns a split air conditioning system complains that his system has been running but his house doesn't seem to be cooling properly. When the service technician arrives on the job - he or she finds that the indoor blower is operating and






12. Which of the following will cause excessive discharge pressures on an air conditioning system...






13. When a high-efficiency split air conditioning system has a plugged metering device - what symptoms might occur...






14. What are three methods for controlling a system's high-side pressure during low ambient conditions...






15. What causes the automatic expansion valve to close...






16. What problem can cause an increase of discharge pressure and an increase of suction pressure...






17. Which of the following problems can cause a decrease in a system's pressures and possible icing of the evaporator coil...






18. When a high-efficiency split air conditioning system has a plugged metering device - what symptoms might occur...






19. A rooftop package system keeps tripping out on the high-pressure switch. What are three possible causes for this problem...






20. A customer calls and says that her air conditioning system is not cooling properly. Upon arrival - a technician notices that the suction line and compressor have frost buildup. Technician A says that the problem is probably a low charge. Technician B






21. If 24 volts are present to the contactor coil on an air conditioning system and the condenser fan or compressor is inoperative - which of the following could be at fault...






22. Technician A says ' When charging a system using the superheat method - adding refrigerant to the system will increase the superheat.' Technician B says 'When charging a system using the superheat method - adding refrigerant will decrease the superhe






23. The technician observes a pressure drop of 25 degrees across an air conditioning evaporator coil at start-up. This drop would indicate...






24. What is the common cause of a compressor burnout...






25. What are possible problems that can cause the discharge-line temperature on an air conditioning system to be cool to the touch...






26. What are the symptoms of a TXV air conditioning system if it has lost its charge...






27. Superheat is found in an air conditioning system in the...






28. What are two common symptoms of an overcharged air conditioning system that uses a capillary-tube-type metering device...






29. A split-system air conditioner that uses a piston-type metering device is to be charged with are-22. Technician A says that the outdoor dry-bulb temperature is needed to determine the proper superheat. Technician B says that the indoor wet-bulb tempe






30. When troubleshooting a split-system air conditioner - it is found that the compressor motor is humming but not starting. Technician A says that it could be an open internal overload protector. Technician B says that it could be a blown fuse. Which te






31. An air conditioning system using a fixed-orifice metering device and with noncondensables in the system will cause...






32. What are the symptoms of an air conditioning system that has a low charge...






33. A system that is operating with a clear sight glass shows...






34. What are two common symptoms of a rooftop air conditioning system that operates with a reverse-acting high-pressure control stuck in the closed position...






35. What is a common temperature difference between the condensing temperature on an air-cooled condensing unit and the outdoor ambient temperature...






36. Air filters should be replaced...






37. What is the purpose of a CPR valve...






38. What are two common symptoms of refrigerant leaks in an air conditioning system...






39. A compressor having tight bearings would cause the current value to...






40. What problem or problems can cause the discharge pressure to be low and the suction pressure to be high...






41. A customer calls and complains that his air conditioning system is not operating properly. It is noticed that the compressor is not operating. A check on the run capacitor shows that there is 33 uf and the rating on the capacitor is 40 uf. Technician






42. A technician receives an air conditioning service call stating that the system is operating but isn't cooling properly. When the technician arrives - she notices that the compressor has recently been changed and it is an are-22 system. She checks the






43. When an air conditioning system has an undercharge - what happens to the superheat and the subcooling of the system...






44. An air conditioning system that uses a fan center has an inoperable indoor blower. When the thermostat is set for cooling and dialed below room temperature - a test with the voltmeter shows that there is 24 volts across terminals 'are' and 'G' at the






45. When an air conditioning system has an undercharge - what happens to the superheat and the subcooling of the system...






46. A party-store owner tried to adjust the water valve on his water-cooled condensing unit - then he called for assistance from an HVAC/are service technician. It was found that when servicing the unit - the outlet water temperature was too low. Technic






47. A system that is operating with a clear sight glass shows...






48. What three things can prevent an air conditioning system from absorbing heat at the proper rate...






49. What problem or problems can cause low discharge and suction pressure...






50. Name two symptoms that are common to an over-charged air conditioning system and a system that has a dirty condenser.