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 is the purpose of an EPR valve...






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






3. 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






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






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






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






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






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






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






10. 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






11. 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






12. 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






13. 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






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






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






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






17. What is the purpose of an EPR valve...






18. 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






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






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






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






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






23. Insufficient airflow can be caused by...






24. 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...






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






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






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






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






29. A commercial customer calls on a 90






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






32. Air filters should be replaced...






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






34. What is the purpose of the TXV...






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






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






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






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






39. 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






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






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






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






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






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






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






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






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






48. 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






49. Insufficient airflow can be caused by...






50. 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