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Residential Air Conditioning

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. Why are some ACR tubing lines insulated?
20 degrees above ambient
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Latent and sensible
Side-by-side and over-and-under

2. If the rpm's are 3450 - how many poles does the motor have?
Slugging
40 degrees F
To remove humidity and lower dry bulb temperature
2

3. At what temperature does refrigerant condense in a standard-efficiency unit?
30-35 degrees above ambient
20 A
ACR (air-conditioning refrigeration) tubing
Boil the liquid refrigerant out ot the oil within the crankcase

4. What is used to measure static air pressure in ducts.
A band 4 inches or more in width
20 A
Inclined manometer
Yes

5. 8' round duct has a ballpark cfm of what?
200
A swaging tool
Nitrogen with a small amount of refrigerant
With an are rating

6. What is the range for normal superheat and subcooling?
Below 800 degrees F
2 minutes
8-12 degrees F
In parallel

7. The fan switch closes at what temperature?
TXV
Inches of water column (in. WC)
Pistons
140 degrees F

8. What do you do after you braze a system?
Pull a vacuum
A diffuser
Inside diameter (ID)
300

9. Do you need a trap on a pull-through evaporator?
25-ft or 50-ft
Over/under and side by side
Yes
400

10. At what temperature will brazing melt?
Duct with insulation on the inside
Individual return air systems and central return air systems
Over 800 degrees F
TXV

11. How is the high pressure switch wired with the low pressure switch?
30-35 degrees above ambient
25-ft or 50-ft
In parallel
The takeoff fitting

12. If the rpm's are 1750 - how many poles does the motor have?
Dehydrated with caps on each end
4
1/4'
Potential relay and start capacitor

13. What are the three pressures created by moving air in ductwork?
100
Static pressure - velocity pressure - and total pressure
With a minimum of three evenly spaced self-tapping screws
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

14. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
Subtract ambient temperature from 100
A bypass duct or a dump zone
Blended refrigerants
L-type

15. How do you achieve high-efficiency?
S-clips and drives (cleats)
By increasing the surface of the condenser coil
Inside diameter (ID)
2 minutes

16. How are the condenser coils different on a high-efficiency unit?
Suction
30 degrees F
They are larger
25-ft or 50-ft

17. How is ACR tubing sized?
8
Outside diameter (OD)
Outside of the male fitting
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line

18. What sort of pressure will a pull-through evaporator have?
It will be low
Nominal-sized tubing
It rises
Negative

19. Do you need a vent on a push-through evaporator?
Negative
Blended refrigerants
140 degrees F
Yes

20. What are the two types of blower drives?
A piston type metering device
Belt drive and direct drive
Nitrogen with a small amount of refrigerant
140 degrees F

21. What standard weight copper tubing is most often used in the heating and air-conditioning industry?
15 A
It will be low
L-type
Yes

22. What is it called when liquid refrigerant gets into the compressor?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
A dirty evaporator
It will be high
Slugging

23. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
They are physically larger
The takeoff fitting
Over/under and side by side

24. What is the typical pressure differance across a TXV?
100 psig
Inclined manometer
6
300

25. At what temperature does refrigerant condense in a high-efficiency unit?
20 degrees above ambient
They are larger
200
Infiltration and ventilation

26. How many amps can 12 g wire handle?
20 A
45-55%
It also rises
40 A

27. A reciprocating compressor has what sort of moving parts?
No
S-clips and drives (cleats)
Btu/hr (output) / wattage (input)
Pistons

28. In what state is the refrigerant in the compressor?
When it is a pull-through evaporator
TXV
6
Vapor

29. What component changes refrigerant from a low pressure gas to a high pressure gas?
The takeoff fitting
Compressor
5 degrees
Indoor fan motor - outdoor fan motor - and the compressor

30. How are round ducts supported?

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31. Which is more efficient - a TXV or a fixed-orifice metering device?
12000
TXV
Stranded
Pistons

32. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Compressor
A bypass duct or a dump zone
Slugging

33. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
100 psig
45 degrees F
No
Any amount

34. How is the high pressure switch wired with the low pressure switch?
ACR (air-conditioning refrigeration) tubing
Shorted winding - open winding - and grounded winding
In parallel
When it is above a conditioned space

35. What do you use to check for leaks?
30-35 degrees above ambient
It rises
Average feet per minute X area in square feet (H' x W'/144)
Nitrogen with a small amount of refrigerant

36. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
Pistons
It will have a decrease in superheat
100 psig
2

37. How many amps can 10 g wire handle?
RLA/FLA x 5
With a minimum of three evenly spaced self-tapping screws
30 A
False

38. Where is insulation used on copper tubing used for air-conditioning?
Infiltration and ventilation
The suction line or the low-pressure side
45-55%
30 degrees F

39. In what length rolls is soft copper tubing normally available?
20 degrees above ambient
30 degrees F
25-ft or 50-ft
To lower the amount of pressure drop through the coil

40. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
L-type
A band 4 inches or more in width
SEER includes the energy used in the start-up and shut-down cycles
Any amount

41. What do you use to check for leaks?
Nitrogen with a small amount of refrigerant
Pi x radius squared
4
100 psig

42. The crankcase heater on an air-conditioning compressor is used to what?
The suction line or the low-pressure side
Boil the liquid refrigerant out ot the oil within the crankcase
18 gauge
To remove humidity and lower dry bulb temperature

43. How long should you leave a system off once you kill power before restarting it?
400
When it is above a conditioned space
2 minutes
30 degrees F

44. When do you install an auxillary drain pan?
300
5 degrees
Indoor fan motor - outdoor fan motor - and the compressor
When it is above a conditioned space

45. A reciprocating compressor has what sort of moving parts?
It will be low
8-12 degrees F
Pistons
Subtract ambient temperature from 100

46. What is lined duct?
To remove humidity and lower dry bulb temperature
Fiberglass
Blended refrigerants
Duct with insulation on the inside

47. What are the two types of package units?
20 A
Subtract ambient temperature from 100
Side-by-side and over-and-under
Outside diameter (OD)

48. What is it called when liquid refrigerant gets into the compressor?
In series
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
30 A
Slugging

49. What sort of pressure will a push-through evaporator have?
Compressor
Positive
Standard
40 degrees F

50. 7' round duct has a ballpark cfm of what?
150
105 degrees F
They are physically larger
1/4'