Test your basic knowledge |

NATE Air Conditioning Troubleshooting

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 are two problems that can cause an air conditioning system to have an excessively high superheat...
Increases starting torque
A dirty evaporator coil+a plugged air filter+a bad indoor blower relay
Technician B
An uninsulated suction line and a restricted metering device

2. 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
Low discharge pressure - high suction pressure - and low amp draw
3 psig
Technician B
The oil pump pressure and the crankcase pressure

3. Insufficient airflow can be caused by...
Technician B
A missing air filter+improper rotation of the indoor blower+blower too small
High suction pressure and low superheat
An increase of air leakage from ductwork

4. The temperature range of the suction line from an air conditioning system should be...
Partially frosted evaporator and high superheat
50-65
Technician A
Technician B

5. The best description of a relay would be...
A bad thermostat
Contains a solenoid coil and one or more sets of contacts
3 psig
An increase of air leakage from ductwork

6. Superheat is found in an air conditioning system in the...
Dirty condenser - bent condenser fins - and air recirculating over the condenser
A plugged filter drier
A vacuum test+oil traces around fittings+soap bubble solution
Evaporator and compressor

7. The temperature range of the suction line from an air conditioning system should be...
The sight glass is full of liquid+the sight glass is full of gas
50-65
An open internal overload protector
An undercharge and low ambient conditions

8. 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
Technician B
The system has been overcharged+The system has air trapped in the condenser
The external equalizer could be plugged
Technician B

9. What is the common cause of a compressor burnout...
The oil pump pressure and the crankcase pressure
An overcharged system
Technician B
Improper system evacuation during installation+short cycling of the system+excessively dirty condenser

10. 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...
An overcharged system
An overcharged system
The internal overload is opened
Technician B

11. What problem or problems can cause low discharge and suction pressure...
'G' to 'C'
An undercharged system+insufficient airflow over the evaporator coil
An overcharged system
Technician B

12. A hard-start kit for an air conditioning system...
The system was improperly serviced and it has air trapped in the condenser or the unit has been overcharged
An uninsulated suction line and a restricted metering device
Dirty condenser - bent condenser fins - and air recirculating over the condenser
Increases starting torque

13. 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
Both technicians are incorrect
High superheat and low discharge pressure
Technician B
Both technicians are correct

14. When an air conditioning system has an undercharge - what happens to the superheat and the subcooling of the system...
3 psig
The superheat increases and the subcooling decreases
High superheat and low discharge pressure
Current in the compressor circuit

15. When a high-efficiency split air conditioning system has a plugged metering device - what symptoms might occur...
A dirty evaporator coil - a defective evaporator fan - and an iced-up evaporator coil
A thermostat cycles the liquid-line solenoid - and a low-pressure switch controls the compressor
A low amp draw - a decrease in high-side pressure - and a decrease in low-side pressure
A missing air filter+improper rotation of the indoor blower+blower too small

16. Name two symptoms that are common to an over-charged air conditioning system and a system that has a dirty condenser.
The discharge pressure increases and the amperage increases
An overcharged system
Can use the thermal electric expansion valve instead of a liquid-line solenoid as part of the pump-down system
Technician B

17. 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...

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

18. Which of the following is a possible cause for a compressor to overheat...
Flooding the condenser - cycling condenser fans - and dampering condenser air
High superheat and low discharge pressure
A low refrigerant charge
Current in the compressor circuit

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
An acid-core suction line drier
Improper system evacuation during installation+short cycling of the system+excessively dirty condenser
Technician B
A thermostat cycles the liquid-line solenoid - and a low-pressure switch controls the compressor

20. Which of the following is a common cause of an excessively low superheat on a TXV system...
A low refrigerant charge
A sensing bulb improperly connected to the suction line
Current in the compressor circuit
A thermostat cycles the liquid-line solenoid - and a low-pressure switch controls the compressor

21. What are two common problems that can cause a sight glass in an air conditioning to have bubbles...
An increase in suction pressure and an increase in discharge pressure
Current in the compressor circuit
Technician B
An undercharge and low ambient conditions

22. What are the symptoms of an air conditioning system that has a bad compressor discharge valve...
A plugged filter drier
Low discharge pressure - high suction pressure - and low amp draw
The sensing bulb at a lower temperature than the valve body
An increase in suction pressure and an increase in discharge pressure

23. 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
Short cycling and insufficient dehumidification
A defective circuit breaker
The system has been overcharged+The system has air trapped in the condenser
The external equalizer could be plugged

24. 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...
Condenser fans operating during a low ambient condition and a low suction pressure
Technician B
A thermostat cycles the liquid-line solenoid - and a low-pressure switch controls the compressor
Lack of airflow

25. 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...
Evaporator and compressor
Condenser fans operating during a low ambient condition and a low suction pressure
The system could be undercharged+The compressor could have bad valves+The system could have a restricted metering device
A blown fuse

26. What is the common cause of a compressor burnout...
An uninsulated TXV sensing bulb
Short cycling and insufficient dehumidification
Improper system evacuation during installation+short cycling of the system+excessively dirty condenser
Technician B

27. What are the symptoms of an air conditioning system that has a low charge...
Current in the compressor circuit
The system could be undercharged+The compressor could have bad valves+The system could have a restricted metering device
Technician B
The low-side pressure will decrease and the evaporator coil will be partially frosted

28. What type of problems can be caused by an oversized air conditioning system...
50-65
Clean the condenser coil
Contains a solenoid coil and one or more sets of contacts
Short cycling and insufficient dehumidification

29. What are two common symptoms of refrigerant leaks in an air conditioning system...
Both technicians are incorrect
Whenever necessary
Partially frosted evaporator and high superheat
It keeps a constant superheat in the evaporator

30. What are three methods for controlling a system's high-side pressure during low ambient conditions...
An undercharged system+insufficient airflow over the evaporator coil
An overcharged system
Evaporator and compressor
Flooding the condenser - cycling condenser fans - and dampering condenser air

31. 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...
A restricted metering device
'G' to 'C'
Low voltage and a faulty start relay
'G' to 'C'

32. 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
Bad compressor valve
An open internal overload protector
It increases pressure in a high-temperature evaporator coil when it is used on a dual-evaporator system
Low voltage and a faulty start relay

33. What problem or problems can cause the discharge pressure to be low and the suction pressure to be high...
Bad compressor valve
Partially frosted evaporator and high superheat
Dirty condenser - bent condenser fins - and air recirculating over the condenser
20 to 30

34. What is a possible cause of a sweat or frost pattern downstream from a sight glass and filter dryer...
Technician B
An overcharged system
A plugged filter drier
Can use the thermal electric expansion valve instead of a liquid-line solenoid as part of the pump-down system

35. What is the purpose of an EPR valve...
It keeps a constant superheat in the evaporator
It increases pressure in a high-temperature evaporator coil when it is used on a dual-evaporator system
Low discharge pressure - high suction pressure - and low amp draw
A bad thermostat

36. The technician observes a pressure drop of 25 degrees across an air conditioning evaporator coil at start-up. This drop would indicate...
Evaporator and compressor
Increases starting torque
Lack of airflow
Dirty condenser - bent condenser fins - and air recirculating over the condenser

37. What is the purpose of a CPR valve...
Technician A
Condenser fans operating during a low ambient condition and a low suction pressure
It is used to control refrigerant pressure in the compressor crankcase
High suction pressure and low superheat

38. What problem or problems can cause low discharge and suction pressure...
A start capacitor and a solid-state relay
An undercharged system+insufficient airflow over the evaporator coil
A defective circuit breaker
Short cycling and insufficient dehumidification

39. When an air conditioning system has an undercharge - what happens to the superheat and the subcooling of the system...
Technician B
The superheat increases and the subcooling decreases
The sight glass is full of liquid+the sight glass is full of gas
It increases pressure in a high-temperature evaporator coil when it is used on a dual-evaporator system

40. What causes the automatic expansion valve to close...
Low voltage and a faulty start relay
Whenever necessary
An undercharged system+insufficient airflow over the evaporator coil
An increase in low-side pressure

41. When using a vapor-charged TXV bulb - it is necessary to have...
The sensing bulb at a lower temperature than the valve body
Broken rings+broken valves+seized bearings
Increases starting torque
Condenser fans operating during a low ambient condition and a low suction pressure

42. 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
An acid-core suction line drier
A restricted metering device
The superheat will increase and the low-side pressure will decrease
Technician B

43. An air conditioning system using a fixed-orifice metering device and with noncondensables in the system will cause...
A defective circuit breaker
The discharge pressure increases and the amperage increases
High superheat and low discharge pressure
Run with high head and high suction pressure

44. 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
Increases starting torque
Technician B
Short cycling and insufficient dehumidification
An overcharged system

45. 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...

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

46. What type of problems can be caused by an oversized air conditioning system...
An increase of air leakage from ductwork
Condenser air being recirculated over the condenser+air trapped in the condenser due to poor service procedures+an overcharged air conditioning system
20 to 30
Short cycling and insufficient dehumidification

47. A liquid-charged TXV bulb will...
Always have some liquid present in the bulb and diaphragm
Technician B
50-65
The superheat will increase and the low-side pressure will decrease

48. What causes the automatic expansion valve to close...
Improper system evacuation during installation+short cycling of the system+excessively dirty condenser
An increase in low-side pressure
Condenser air being recirculated over the condenser+air trapped in the condenser due to poor service procedures+an overcharged air conditioning system
A vacuum test+oil traces around fittings+soap bubble solution

49. Which of the following could be the cause for a system's discharge and suction pressure being low...
A restricted metering device
It increases pressure in a high-temperature evaporator coil when it is used on a dual-evaporator system
An overcharged system
Technician B

50. 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
Technician A
Condenser fans operating during a low ambient condition and a low suction pressure
A dirty evaporator coil+a plugged air filter+a bad indoor blower relay
Run with high head and high suction pressure