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






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






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






4. 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






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






6. What is a possible cause of a sweat or frost pattern downstream from a sight glass and filter dryer...






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






8. 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






9. Air filters should be replaced...






10. Insufficient airflow can be caused by...






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






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






13. 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...






14. When using a vapor-charged TXV bulb - it is necessary to have...






15. 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...






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






17. What is the purpose of the TXV...






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






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






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






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






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






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






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






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






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






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






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






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






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






31. 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






32. What is a possible cause of a sweat or frost pattern downstream from a sight glass and filter dryer...






33. 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






34. 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...






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






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






37. 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...






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






39. 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






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






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






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






43. A system that is being serviced has been evacuated down to 500 microns. When the gauges are closed and the vacuum pump is turned off - the pressure starts to increase and stops at 1000 microns. Technician A says that the system has a leak and needs t






44. 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






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






46. 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






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






48. A commercial customer calls on a 90






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






50. 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