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






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






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






4. What type of problems can be caused by an oversized air conditioning system...






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






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






7. 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






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






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






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






11. 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






12. 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






13. 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






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






15. 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...






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






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






18. 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






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






20. 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






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






22. A 220-volt 30-amp motor circuit keeps tripping the breaker after the motor is started. The starting amperage is 60 amps. When measuring the amperage of the circuit - This is drawn for a brief moment. After startup - the amperage drops to 22 amps and






23. Which of the following could be the cause for a system's discharge and suction pressure being low...






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






25. 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...






26. Insufficient airflow can be caused by...






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






28. 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






29. 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






30. The technician observes that the compressor is not operating. The compressor windings read 5 ohms start to run - run to common is opened - and start to common is opened. The technician concludes that...






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






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






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






34. Insufficient airflow can be caused by...






35. 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...






36. What is the purpose of the TXV...






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






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






39. 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






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






41. 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






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






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






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






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






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






47. The technician observes that the compressor is not operating. The compressor windings read 5 ohms start to run - run to common is opened - and start to common is opened. The technician concludes that...






48. 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






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






50. A compressor motor starts and operates for a short period of time and cycles on the external overload protector. What are two possible problems that could cause this...