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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. What are the two types of blower drives?
Belt drive and direct drive
Positive
When it is a pull-through evaporator
Individual return air systems and central return air systems

2. If the rpm's are 1050 - how many poles does the motor have?
To lower the amount of pressure drop through the coil
To remove humidity and lower dry bulb temperature
6
Outside diameter (OD)

3. What are the two functions of the air-conditioning system?
8-12 degrees F
To remove humidity and lower dry bulb temperature
RLA/FLA x 5
400

4. How do you calculate the area of a circle?
Pi x radius squared
15 A
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
300

5. How many amps can 8 g wire handle?
20 A
TXV
100 psig
40 A

6. Superheat should never be below how many degrees
Pull a vacuum
Below 800 degrees F
Over/under and side by side
5 degrees

7. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Positive
20 degrees F
Rise
Heat loss

8. How many amps can 10 g wire handle?
With 4' saddles
140 degrees F
Heat load
30 A

9. Which is more efficient - a TXV or a fixed-orifice metering device?
100 psig
2 minutes
Compressor
TXV

10. What kind of copper tubing is used for plumbing and heating applications?
Yes
Pull a vacuum
12000
Nominal-sized tubing

11. The fan switch opens at what temperature?
8-12 degrees F
Nitrogen with a small amount of refrigerant
105 degrees F
On the common terminal

12. How many amps can 12 g wire handle?
Staples and tape
18 gauge
On the common terminal
20 A

13. Superheat should never be below how many degrees
Inclined manometer
Inches of water column (in. WC)
4
5 degrees

14. What are the three pressures created by moving air in ductwork?
Rise
When it is above a conditioned space
Static pressure - velocity pressure - and total pressure
2 minutes

15. Where do you install a trap on a drain line?
Before the vent
30-35 degrees above ambient
Pistons
Standard

16. How many amps can 14 g wire handle?
Average feet per minute X area in square feet (H' x W'/144)
15 A
Standard
Rise

17. What is the normal evaporator temperature?
45 degrees F
High
20 A
Slugging

18. How do you calculate ballpark superheat?
ACR (air-conditioning refrigeration) tubing
6
Subtract ambient temperature from 100
Yes

19. At what temperature does refrigerant condense in a high-efficiency unit?
150
Stranded
20 degrees above ambient
By increasing the surface of the condenser coil

20. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
They are physically larger
30 degrees F
The takeoff fitting
400

21. The furnace size is calculated by what?
Heat loss
Standard
400
400

22. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
They are physically larger
It also rises
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
15% silphos

23. 9' round duct has a ballpark cfm of what?
300
A swaging tool
True
Yes

24. If the rpm's are 750 - how many poles does the motor have?
It rises
8
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
To lower the amount of pressure drop through the coil

25. What are the two basic duct connection configurations for package units supply and return air ducts?
Over/under and side by side
30 A
15% silphos
300

26. How many amps can 8 g wire handle?
2 minutes
40 A
400
When the system is under pressure

27. What are the three ways a motor can fail electrically?
Shorted winding - open winding - and grounded winding
The suction line or the low-pressure side
20 degrees above ambient
Negative

28. What tool is used to expand the diameter of soft copper tubing
RLA/FLA x 5
A swaging tool
Over 800 degrees F
True

29. What are the three major power-consuming devices on an air-conditioning system?
Indoor fan motor - outdoor fan motor - and the compressor
With an are rating
On the common terminal
Pi x radius squared

30. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
30-35 degrees above ambient
By increasing the surface of the condenser coil
It will have a decrease in superheat
400

31. How is the high pressure switch wired with the low pressure switch?
When the system is under pressure
In parallel
Vapor
Indoor fan motor - outdoor fan motor - and the compressor

32. Square sheet metal duct is normally fabricated in a sheet metal shop and assembled in the field. (True or False)
False
Belt drive and direct drive
A bypass duct or a dump zone
True

33. How do you calculate the area of a circle?
Pi x radius squared
It will be high
A band 4 inches or more in width
140 degrees F

34. If the suction pressure rises - what happens to the head pressure?
They are larger
Inches of water column (in. WC)
Outside diameter (OD)
It also rises

35. How do you calculate cfm?

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36. What is it called when liquid refrigerant gets into the compressor?
20 degrees F
100
Slugging
Suction

37. When do you install a trap on a drain line?
300
When it is above a conditioned space
No
When it is a pull-through evaporator

38. Can refrigerant line sets be altered in length?
Blended refrigerants
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Yes
30 A

39. What are the components of a hard-start kit?
Potential relay and start capacitor
Pistons
True
Standard

40. If the rpm's are 3450 - how many poles does the motor have?
30 degrees F
2
Belt drive and direct drive
With an are rating

41. On what terminal do you check amperage?
When the system is under pressure
Common
15 A
100 psig

42. How many cfm per ton?
400
Individual return air systems and central return air systems
True
12000

43. 10' round duct has a ballpark cfm of what?
Latent and sensible
400
It will be high
12000

44. How does ACR copper pipe come?
Dehydrated with caps on each end
Boil the liquid refrigerant out ot the oil within the crankcase
8-12 degrees F
2

45. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Pistons
It also rises
45-55%
A piston type metering device

46. What is a package unit?
40 degrees F
To lower the amount of pressure drop through the coil
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
40 degrees F

47. What is it called when liquid refrigerant gets into the compressor?
Yes
Slugging
A band 4 inches or more in width
18 gauge

48. What are the two types of package units?
Average feet per minute X area in square feet (H' x W'/144)
S-clips and drives (cleats)
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Side-by-side and over-and-under

49. Why is it necessary to have multiple refrigerant circuits in some evaporator coils?
To lower the amount of pressure drop through the coil
30-35 degrees above ambient
Duct with insulation on the inside
Individual return air systems and central return air systems

50. The evaporator is designed to remove what two types of heat?
Latent and sensible
400
RLA/FLA x 5
Boil the liquid refrigerant out ot the oil within the crankcase