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






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






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






4. 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






5. 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...






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






7. 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






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






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






10. A commercial customer calls on a 90






11. 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






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






13. 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






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






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






16. 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...






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






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






19. 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...






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






21. 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






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






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






24. 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






25. A hard-start kit for an air conditioning system...






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






27. What controls are used on air conditioning or refrigeration systems that incorporate an automatic pump-down system...






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






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






30. 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






31. 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...






32. 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






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






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






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






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






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






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






39. 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...






40. Air filters should be replaced...






41. 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






42. 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






43. 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...






44. A commercial customer calls on a 90






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






46. A commercial customer calls complaining that her rooftop air conditioning system is not operating. The technician arrives on the job and sets the thermostat to cooling - then notices that the indoor fan is not operating. The technician then sets the






47. Insufficient airflow can be caused by...






48. Insufficient airflow can be caused by...






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






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