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






2. 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






3. 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






4. What is a common discharge temperature of an air-cooled air conditioning system that is used on a 90






5. Why is it unsafe to operate an air conditioning system with a low charge...






6. Which of the following is a possible cause for a compressor to overheat...






7. 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






8. A customer calls to complain that his central air conditioning system is not cooling properly. The technician arrives on the job. He or she notices that the indoor blower has adequate airflow and the outdoor condenser fan is operating - but the compr






9. Technician A says that if you connect 208 volts to the primary side of a 240-volt/ 24-volt transformer - the transformer will burn out. Technician B says that if you connect 208 volts to the primary side of a 240-volt/24-volt transformer - the contro






10. After a compressor motor has been severely burnt - What accessory must be added as an aid to rid the air conditioning system of acid...






11. What component is most often the cause of a start capacitor failure...






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






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






14. An air conditioning unit has a suction line that is frosted up to the compressor. What faults could cause this to occur...






15. A technician arrives on the job and the customer complains that there is no cooling on his rooftop unit. Troubleshooting the system - the technician finds that the compressor is faulty. He notices that there is another faulty compressor laying next t






16. What are the symptoms of an air conditioning system that has a bad compressor discharge valve...






17. A customer calls with an insufficient cooling complaint. Upon arrival to the service call it is found that the system is using are-22 with the high-side pressure at 290 psig and the low-side pressure at 85 psig. The ambient temperature is 85






18. When testing an indoor blower control circuit and the cooling circuit on a fan center - what terminals should read 24 volts if the air conditioning system is in operation...






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






20. A customer calls with an insufficient cooling complaint on a 90






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






22. If a rooftop air conditioning system does not have any means of low ambient protection - what will be two symptoms of the system when operating under a low ambient condition...






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






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






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






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






27. 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






28. 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






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






30. The best description of a relay would be...






31. The temperature range of the suction line from an air conditioning system should be...






32. Insufficient airflow can be caused by...






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






34. A customer calls and complains that her high-efficiency air conditioning system is operating - but is not cooling properly. Further investigation shows that the system is using a TXV type of metering device. A subcooling check shows that the system a






35. A customer calls with an insufficient cooling complaint. Upon arrival to the service call it is found that the outdoor condensing unit is operating - but the indoor blower is not in operation. Technician A says that it is possible that it is a bad fu






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






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






38. What are the operating pressures of an oil pressure safety switch...






39. A liquid-charged TXV bulb will...






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






41. A hard-start kit consists of...






42. 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






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






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






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






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






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






48. A system that uses a thermal electric expansion valve...






49. Which of the following can cause low superheat in a TXV system...






50. A liquid-charged TXV bulb will...