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






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






3. A commercial customer calls on a 90






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






5. 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






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






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






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






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






10. A commercial customer calls on a 90






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






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






13. A restricted air filter in an air conditioning system can be identified by...






14. 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...






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






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






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






18. 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






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






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






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






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






23. 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






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






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






26. 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






27. 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






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






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






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






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






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






33. 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






34. 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






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






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






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






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






39. 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






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






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






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






43. 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






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






45. 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






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






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






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






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






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