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






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






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






4. 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...






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






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






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






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






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






10. 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






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






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






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






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






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






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






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






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






19. 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






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






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






22. 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






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






24. 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






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






26. 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






27. 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






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






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






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






31. 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...






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






33. 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






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






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






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






37. 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






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






39. 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






40. 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






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






42. Insufficient airflow can be caused by...






43. 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...






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






45. 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






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






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






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






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