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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. 10' round duct has a ballpark cfm of what?
L-type
400
Pull a vacuum
False

2. What is the typical temperature difference between a standard-efficiency condenser and the ambient temperature?
100 psig
30 degrees F
False
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity

3. If the rpm's are 1750 - how many poles does the motor have?
4
20 A
On the common terminal
Fiberglass

4. What is considered normal operating conditions?
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
They are larger
TXV
Average feet per minute X area in square feet (H' x W'/144)

5. What are normal conditions - as defined by the ARI.
The suction line or the low-pressure side
TXV
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
12000

6. What is the typical temperature difference between a high-efficiency condenser and the ambient temperature?
20 degrees F
Subtract ambient temperature from 100
TXV
Sheet metal - galvanized sheet metal - fiberglass - and flexduct

7. What are the two types of return air systems in residential installations?
With a minimum of three evenly spaced self-tapping screws
Nominal-sized tubing
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
Individual return air systems and central return air systems

8. How is insulation around a duct rated?
Outside diameter (OD)
It rises
Duct - electrical - and mechanical
With an are rating

9. How is insulation around a duct rated?
TXV
It rises
With an are rating
To remove humidity and lower dry bulb temperature

10. Do you need a trap on a pull-through evaporator?
Potential relay and start capacitor
1/4'
30 degrees F
Yes

11. How does ACR copper pipe come?
The takeoff fitting
Yes
Dehydrated with caps on each end
When it is above a conditioned space

12. What kind of refrigeratnts must be added in liquid form?
To lower the amount of pressure drop through the coil
False
Latent and sensible
Blended refrigerants

13. What are the three ways a motor can fail electrically?
Shorted winding - open winding - and grounded winding
Positive
Duct with insulation on the inside
2

14. The crankcase heater on an air-conditioning compressor is used to what?
20 A
45 degrees F
Pistons
Boil the liquid refrigerant out ot the oil within the crankcase

15. Do you need a trap on a pull-through evaporator?
Nominal-sized tubing
Yes
Nitrogen with a small amount of refrigerant
In parallel

16. What is the design boiling point for most evaporator coils in residential air conditioning?
To lower the amount of pressure drop through the coil
40 degrees F
Standard
200

17. Why are some ACR tubing lines insulated?
RLA/FLA x 5
To keep refrigerant from absorbing heat and to prevent condensation from forming on the line
12000
30 A

18. Where do you apply flux when soldering?
A dirty evaporator
Outside of the male fitting
By increasing the surface of the condenser coil
30 degrees F

19. How many amps can 14 g wire handle?
6
15 A
Indoor fan motor - outdoor fan motor - and the compressor
200

20. What is a package unit?
Pi x radius squared
5 degrees
The takeoff fitting
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.

21. How many amps can 12 g wire handle?
Over 800 degrees F
Common
2 minutes
20 A

22. How will too much refrigerant effect subcooling?
A diffuser
Belt drive and direct drive
Yes
It will be high

23. What kind of copper tubing is used for plumbing and heating applications?
False
Nominal-sized tubing
Fiberglass
400

24. What is the name of the fitting where the branch line leaves the duct?
The takeoff fitting
A bypass duct or a dump zone
25-ft or 50-ft
Potential relay and start capacitor

25. 13 SEER is classified as what kind of efficiency?
Heat loss
Belt drive and direct drive
Negative
High

26. What is lined duct?
Heat load
Duct with insulation on the inside
In parallel
They are physically larger

27. What sort of pressure will a push-through evaporator have?
Slugging
Boil the liquid refrigerant out ot the oil within the crankcase
Below 800 degrees F
Positive

28. If the rpm's are 1050 - how many poles does the motor have?
6
Shorted winding - open winding - and grounded winding
8
Individual return air systems and central return air systems

29. 9' round duct has a ballpark cfm of what?
18 gauge
Slugging
Pistons
300

30. What are the three crafts normally associated with an air-conditioned installation?
15 A
Duct - electrical - and mechanical
SEER includes the energy used in the start-up and shut-down cycles
Outside of the male fitting

31. What are normal conditions - as defined by the ARI.
95 degrees F outside - 80 degrees F inside - and 50% relative humidity
Outside of the male fitting
True
A band 4 inches or more in width

32. What is it called when liquid refrigerant gets into the compressor?
True
Rise
Slugging
It will have a decrease in superheat

33. The crankcase heater on an air-conditioning compressor is used to what?
400
Duct with insulation on the inside
When it is above a conditioned space
Boil the liquid refrigerant out ot the oil within the crankcase

34. What is the typical pressure differance across a TXV?
Nitrogen with a small amount of refrigerant
100 psig
Outside diameter (OD)
8

35. What is the typical pressure differance across a TXV?
It also rises
8
100 psig
Pi x radius squared

36. How many amps can 14 g wire handle?
30 A
Average feet per minute X area in square feet (H' x W'/144)
Duct with insulation on the inside
15 A

37. What can cause a decrease in suction pressure on an air-conditioning system?
L-type
6
A dirty evaporator
Indoor fan motor - outdoor fan motor - and the compressor

38. How many amps can 10 g wire handle?
L-type
30 A
Negative
1/4'

39. Do you need a trap on a push-through evaporator?
Any amount
No
Heat loss
Subtract ambient temperature from 100

40. The load on the evaporater will effect which pressure?
Suction
75 degrees F dry bulb indoor - 95 degrees F drybulb outdoor - and 50% relative humidity
Slugging
95 degrees F outside - 80 degrees F inside - and 50% relative humidity

41. How are round ducts supported?

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42. The A/C size is calculated by what?
Negative
400
The takeoff fitting
Heat load

43. Where do you check the amps on a motor?
Outside diameter (OD)
On the common terminal
Common
200

44. When must a copper joint never be soldered or brazed?
In parallel
Shorted winding - open winding - and grounded winding
When the system is under pressure
100

45. How are round ducts supported?

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46. What do you use to check for leaks?
They are physically larger
Rise
Nitrogen with a small amount of refrigerant
Outside of the male fitting

47. How is the high pressure switch wired with the low pressure switch?
Yes
High
Negative
In parallel

48. A reciprocating compressor has what sort of moving parts?
An air-conditioning system that has all four components (compressor - condenser - metering device - and evaporator) in one housing.
Pistons
Vapor
It will be high

49. What are the two types of blower drives?
Belt drive and direct drive
8
Inside diameter (ID)
The takeoff fitting

50. At what temperature does refrigerant condense in a standard-efficiency unit?
In series
30-35 degrees above ambient
Below 800 degrees F
30 A