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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. Multiple-zone systems often use what to alleviate the problem of excess air when only some zones are calling for conditioning?
400
4
A bypass duct or a dump zone
1/4'

2. If the rpm's are 1750 - how many poles does the motor have?
Inclined manometer
When the system is under pressure
Outside of the male fitting
4

3. How many amps can 10 g wire handle?
Before the vent
4
30 degrees F
30 A

4. What is lined duct?
Sheet metal - galvanized sheet metal - fiberglass - and flexduct
45 degrees F
No
Duct with insulation on the inside

5. How much superheat do you need to prevent liquid refrigerant from entering the compressor?
By increasing the surface of the condenser coil
150
It rises
Any amount

6. What percentage silver do you use to braze two dissimilar metals such as steel and copper?
Infiltration and ventilation
45-55%
Common
105 degrees F

7. What are the two types of blower drives?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
With 4' saddles
When the system is under pressure
Belt drive and direct drive

8. If the rpm's are 750 - how many poles does the motor have?
Inside diameter (ID)
8
Before the vent
105 degrees F

9. If the rpm's are 750 - how many poles does the motor have?
A bypass duct or a dump zone
On the common terminal
It also rises
8

10. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
It will have a decrease in superheat
A piston type metering device
Belt drive and direct drive
It also rises

11. 9' round duct has a ballpark cfm of what?
25-ft or 50-ft
300
Duct - electrical - and mechanical
15 A

12. What are the three ways a motor can fail electrically?
30 degrees F
Shorted winding - open winding - and grounded winding
Staples and tape
It also rises

13. What is the name of the fitting where the branch line leaves the duct?
Heat loss
Yes
Latent and sensible
The takeoff fitting

14. The compressor is cooled by liquid refrigerant. (True of False)
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Blended refrigerants
False
Outside diameter (OD)

15. What are the two basic duct connection configurations for package units supply and return air ducts?
Duct - electrical - and mechanical
Over/under and side by side
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Average feet per minute X area in square feet (H' x W'/144)

16. What tool is used to expand the diameter of soft copper tubing
Duct with insulation on the inside
A swaging tool
Shorted winding - open winding - and grounded winding
Yes

17. At what temperature does refrigerant condense in a high-efficiency unit?
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
20 degrees above ambient
TXV
Dehydrated with caps on each end

18. What gauge is thermostat wire?
Inside diameter (ID)
40 A
18 gauge
Yes

19. Do you need a trap on a pull-through evaporator?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
With an are rating
Outside diameter (OD)
Yes

20. How will an overcharge affect an air-conditioning system with a fixed-orifice type metering device?
On the common terminal
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Fiberglass
It will have a decrease in superheat

21. 13 SEER is classified as what kind of efficiency?
High
Infiltration and ventilation
It will be low
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

22. What percentage silver do you need to use for an are-410 system?
To remove humidity and lower dry bulb temperature
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
15% silphos
Inside diameter (ID)

23. How do you calculate the area of a circle?
Pi x radius squared
Yes
40 degrees F
Pistons

24. If the suction pressure rises - what happens to the head pressure?
Staples and tape
It also rises
Duct - electrical - and mechanical
Indoor fan motor - outdoor fan motor - and the compressor

25. What are the three major power-consuming devices on an air-conditioning system?
6
Indoor fan motor - outdoor fan motor - and the compressor
With 4' saddles
It also rises

26. Which type of wire can handle a higher ampacity?
Side-by-side and over-and-under
Stranded
Common
By increasing the surface of the condenser coil

27. Where do you apply flux when soldering?
30 degrees F
With 4' saddles
Outside of the male fitting
They are larger

28. How are the condenser coils different on a high-efficiency unit?
They are larger
Outside of the male fitting
15% silphos
Side-by-side and over-and-under

29. When must a copper joint never be soldered or brazed?
It will have a decrease in superheat
30 degrees F
When the system is under pressure
Pull a vacuum

30. What is the normal evaporator temperature?
Negative
Common
45 degrees F
2

31. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Inside diameter (ID)
Pistons
30 A

32. What component changes refrigerant from a low pressure gas to a high pressure gas?
Compressor
1/4'
Pull a vacuum
20 degrees F

33. If the rpm's are 1750 - how many poles does the motor have?
4
Subtract ambient temperature from 100
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Potential relay and start capacitor

34. The fan switch closes at what temperature?
A dirty evaporator
ACR (air-conditioning refrigeration) tubing
40 A
140 degrees F

35. 7' round duct has a ballpark cfm of what?
Any amount
150
Positive
15 A

36. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
Heat loss
Positive
When it is a pull-through evaporator
20 degrees F

37. On what terminal do you check amperage?
Common
Heat load
Inches of water column (in. WC)
30-35 degrees above ambient

38. How do you calculate ballpark superheat?
Individual return air systems and central return air systems
Duct - electrical - and mechanical
Subtract ambient temperature from 100
Standard

39. How are high-efficiency condenser coils different from standard-efficiency condenser coils?
20 degrees above ambient
They are larger
Yes
They are physically larger

40. What is the design boiling point for most evaporator coils in residential air conditioning?
Latent and sensible
Average feet per minute X area in square feet (H' x W'/144)
40 degrees F
400

41. The fan switch opens at what temperature?
In series
140 degrees F
Infiltration and ventilation
105 degrees F

42. What are the two types of return air systems in residential installations?
Over/under and side by side
Individual return air systems and central return air systems
With 4' saddles
Rise

43. What are the two functions of the air-conditioning system?
15% silphos
S-clips and drives (cleats)
Over/under and side by side
To remove humidity and lower dry bulb temperature

44. How is nominal-sized tubing sized?
L-type
40 degrees F
Inside diameter (ID)
8

45. Does a package unit come from the factory pre-charged?
15 A
20 A
Yes
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

46. What do you do after you braze a system?
Average feet per minute X area in square feet (H' x W'/144)
Pull a vacuum
30 degrees F
140 degrees F

47. How are round ducts connected to one another?
Subtract ambient temperature from 100
Inches of water column (in. WC)
With a minimum of three evenly spaced self-tapping screws
With 4' saddles

48. How do you calculate LRA?
40 A
RLA/FLA x 5
A bypass duct or a dump zone
Yes

49. What is the range for normal superheat and subcooling?
In series
Rise
8-12 degrees F
2

50. 7' round duct has a ballpark cfm of what?
Inclined manometer
Yes
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
150