1 Exam Prep – Trane Reciprocating Refrigeration 1 1 Exam Prep Trane Reciprocating Refrigeration Questions and Answers 1. When the temperature difference between the refrigerant gas and the water increases the capacity of the condenser is _____________? A Decreased B Static C Increased D Transferred 2. High efficiency forced or induced draft cooling towers will cool the condenser water to a point _________? A Within 5 to 8 degrees of the prevailing wet bulb temperature B 10 degrees below boiling C 10 degrees above boiling D Within 5 to 8 degrees of the prevailing dry bulb temperature 3. A straight induction motor is a/an_____________? A Squirrel Cage Motor B Total Enclosed Motor C Open Motor D Totally Enclosed Fan-Cooled Motor 4. When testing a system for leaks, connect to the frontseat port of the compressor discharge valve a cylinder of______________? A Acetylene B Oxygen (oil-free) C Oil-pumped dry nitrogen D Dry pumped oil free nitrogen 5. The superheat setting for most air conditioning systems is______________? A 10F B Approximately 8 to 11 F C 12F D Approximately 12 to 15 F 6. The type of cooling coils rated on the basis of approximately 10 degrees superheat is_______________? A Direct thermo expansion B Direct Expansion C Indirect thermo expansion D Indirect Expansion
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1 Exam Prep – Trane Reciprocating Refrigeration 1
1 Exam Prep
Trane Reciprocating Refrigeration
Questions and Answers
1. When the temperature difference between the refrigerant gas and the water increases the capacity of the
condenser is _____________?
A Decreased
B Static
C Increased
D Transferred
2. High efficiency forced or induced draft cooling towers will cool the condenser water to a point _________?
A Within 5 to 8 degrees of the prevailing wet bulb temperature
B 10 degrees below boiling
C 10 degrees above boiling
D Within 5 to 8 degrees of the prevailing dry bulb temperature
3. A straight induction motor is a/an_____________?
A Squirrel Cage Motor
B Total Enclosed Motor
C Open Motor
D Totally Enclosed Fan-Cooled Motor
4. When testing a system for leaks, connect to the frontseat port of the compressor discharge valve a cylinder
of______________?
A Acetylene
B Oxygen (oil-free)
C Oil-pumped dry nitrogen
D Dry pumped oil free nitrogen
5. The superheat setting for most air conditioning systems is______________?
A 10F
B Approximately 8 to 11 F
C 12F
D Approximately 12 to 15 F
6. The type of cooling coils rated on the basis of approximately 10 degrees superheat is_______________?
A Direct thermo expansion
B Direct Expansion
C Indirect thermo expansion
D Indirect Expansion
1 Exam Prep – Trane Reciprocating Refrigeration 2
7. The closing of the normally open second auxiliary contacts of the fan or chilled water pump starter completes
the ______________________?
A Low voltage control circuit to the temperature controller
B High voltage control circuit to the temperature controller
C Low voltage control circuit to the condenser
D Low voltage control circuit to the fan
8. Within horizontal refrigerant gas carrying lines the minimum gas velocity is ________________?
A 400 feet per minute
B 750 feet per minute
C 500 feet per minute
D 650 feet per minute
9. The motor enclosure in which air is circulated directly over the motor windings is______________?
A Slip Ring Motor
B Splash-proof Motor
C Explosion-proof Motor
D Open Motor
10. An additional load is placed on the condenser when ___________?
A Heat is lost by the suction lines
B Heat is maintained on the suction lines
C Heat is gained by the suction lines
D Chilling is gained by the expansion line
11. For leak testing it is recommended dry nitrogen be charged to the system through the valve of a/an ______?
A Gauge manifold
B Intake manifold
C Pressure gauge
D Directional manifold
12. To wire a dual voltage motor for lower voltage (230 volt) full winding start, the windings are __________?
A Wired in series
B Wired in parallel
C Overlapped
D Omni-directional
13. The system required for a single discharge line sized to maintain the required 1,000 feet per minute
minimum load gas velocity within the hot gas riser is__________________?
A A single riser system
B A triple riser system
C A double riser system
D Bypass gate valve riser system
1 Exam Prep – Trane Reciprocating Refrigeration 3
14. The amount of friction loss within a pipe is__________________?
A Mineral content of the water
B Dependent upon the condition of the pipe and the velocity of the water
C Absorption capacity of the pipe and the velocity
D Size of the pipe and the condition of the pipe
15. An instrument for measuring temperature is a/an ______________?
A Thermometer
B Thermostat
C Dry Bulb
D Wet Bulb
16. If load variations are wide and subject to rapid changes expansion valves should be set for superheats from?
A 10 to 15 degrees
B 10 to 12 degrees
C 12 to 15 degrees
D 8 to 12 degrees
17. When testing for leaks, the nitrogen cylinder pressure regulator setting is_______________?
A 150 psig
B 125 psig or the leak test pressure specified by local code.
C 130 psig
D 150 psig or the leak test pressure specified by local code.
18. The present concept of a cooling tower was reached when?
A Electricity was available to run the system
B A fan that either pushed or pulled the air through the tower was added
C A condenser was added to the system
D Blow-down control was obtained
19. A controller producing a modulated control signal is a/an_________________?
A Two-Position Controller
B On-Off Controller
C Proportional Controller
D Pneumatic Controller
20. Based on 40 F suction and 105 F condensing liquid lines 40 feet in length connected to a 148 tons with a
total pressure drop 5 psi, the copper tube size needed when using R-22 is ___________?
A 1 3/8 inch
B 1 5/8 inch
C 1 3/4 inch
D 1 1/8 inch
1 Exam Prep – Trane Reciprocating Refrigeration 4
21. Given: Saturated refrigerant-502 having a 152.32 psia and a 137.62 psig the gas temperature is?
A 78 F
B 60 F
C 76 F
D 70 F
22. The boiling point of liquid and the condensing temperature of vapor are _______________?
A Exactly the same at any one pressure is
B Always different regardless of temperature
C Always the same at any given fluid level
D Co-dependent
23. Given: Saturated refrigerant-22 with a temperature of 106F and a psia of 228.50. The psig is?
A 201.76
B 228.50
C 213.81
D 207.72
24. Given: Suction gas velocities for refrigerant-22 with a 1 5/8 inch line outside diameter, Type L copper
tubing carrying 25 tons. The gas velocity is?
A 4,500 feet per minute
B 3,000 feet per minute
C 5,000 feet per minute
D 4,000 feet per minute
25. Based on 40 F suction and 105 F condensing lines delivering liquid refrigerant from receiver to evaporator
with equivalent length of 100 feet. The copper tube size-OD-Type L to support 18.7 tons with a pressure drop
of 3 psi is when using R-22 is?
A 1 3/8 inch
B 7/8 inch
C 1 1/8 inch
D 3/4 inch
26. Liquid refrigerant may pass from the evaporator into the suction line if ______________?
A The thermostatic expansion valve is adjusted to produce too little superheat
B The thermostatic expansion valve is closed
C The thermostatic expansion valve is open
D The humidity ratio is above normal
1 Exam Prep – Trane Reciprocating Refrigeration 5
27. Given: Suction gas velocities for refrigerant-22 carrying 1500 feet per minute for 25 tons.
The outside diameter for type-L copper tubing should be ________________?
A 2 1/8 inches
B 3 1/8 inches
C 7/8 inches
D 2 5/8 inches
28. Given: Based on 40 F suction and 105 F condensing suction lines delivering refrigerant-22 vapor from
evaporator to compressor with equivalent length of 40 feet, total pressure
drop of 0.5 psi, the copper tube size to support 10.2 tons is __________?
A 2 1/8 inches
B 1 5/8 inches
C 1 3/8 inches
D 1 1/8 inches
29. Given: Based on 40° F suction and 105 F condensing a 7/8 inch copper tube line delivering liquid
refrigerant-22 from receiver to evaporator with equivalent length of 125 feet carrying 16.0 tons the total
pressure drop is ___________?
A 7 psi
B 2 psi
C 5 psi
D 3 psi
30. Given: Based on 40 F suction and 105 F condensing discharge lines delivering refrigerant-22 vapor from
compressor to condenser that has an equivalent length of 40 feet carrying 52.3 tons with total pressure drop of 5
psi the size copper tube size is __________?
A 3 1/8 inches
B 1 5/8 inches
C 2 1/8 inches
D 1 3/8 inches
31. Most air conditioning applications are satisfactory when the superheat is adjusted at?
A 12 to 15 F superheat
B 10 to 12 F superheat
C 8 to 10 F superheat
D 11 to 15 F superheat
32. The amount of heat produced by a motor is a function of ________________?
A Energy and humidity
B Efficiency and load
C Temperature and enthalpy
D Coil impact and resistance
1 Exam Prep – Trane Reciprocating Refrigeration 6
33. Methods of air cooled condenser capacity control currently used include all of the following except?
A Relay
B Damper
C Fan cycling
D Flood-back
34. Damper control is adequate for condensing ambient air temperatures down to approximately
______________ degrees Fahrenheit.
A 50
B 45
C 40
D 35
35. Gauges used for air conditioning work should be____________?
A Designed for commercial use
B Designed for refrigeration service
C Generic
D Easy to install and work with
36. Suction line is being sized for a job. Chilly Pete notes a 90 degree Fahrenheit condensing temperature and a
10 degree Fahrenheit suction temperature. Using R- 22, the suction line correction factor is?
A 1.69
B 1.49
C 1.31
D 1.29
37. When using refrigerant 12 or 22, the refrigerant piping in the system must be?
A Pre-treated
B Lubricated
C Made of refrigerant tubing which has been cleaned by the manufacturer
D Absolutely clean
38. A compressor fails to start for all of the following reasons except _______________?
A Power failure
B Low voltage
C Burned out motor
D Lack of refrigerant
1 Exam Prep – Trane Reciprocating Refrigeration 7
39. While troubleshooting a refrigeration system, Rob observes bubbles in the sight glass and determines the
system needs refrigerant. Rob will _______________?
A Repair or replace the valve, then charge the system
B Find and repair the leak, then charge the system
C Reset the compressor capacity control range
D Add refrigerant, then run a test
40. A device used to measure gas pressures both above and below atmospheric pressure is called
a gauge?
A Pressure
B Multi-purpose
C Convex
D Compound
41. Given R22 at 196 PSIG, the temperature of saturated refrigerant in the receiver is __________?
A 95 degrees
B 136 degrees
C 130 degrees
D 100 degrees
42. Given R 22 at 260 PSIG. The refrigerant leaves the condenser at 114 degrees Fahrenheit. The refrigerant is
subcooled ________?
A 4 degrees
B 6 degrees
C 8 degrees
D 10 degrees
43. A walk-in freezer uses R-22 refrigerant. The low pressure cutout is at 12.5 PSIG. To lower the temperature
6 degrees, the low pressure cutout must be set at ___________?
A 9.0
B 10.0
C 11.0
D 12.0
44. The temperature is 42 degrees Fahrenheit. The contractor is using R-22. Suction pressure should be ______?
A 68 PSIA
B 86 PSIA
C 98 PSIA
D 105 PSIA
1 Exam Prep – Trane Reciprocating Refrigeration 8
45. Voltage readings were taken with the following results: 231 V, 227V and 233V. The percent of variance is
_____________?
A 1.4
B 1.75
C 1.9
D 2.0
46. A storage tank contains R-22. The outside air temperature is 140 degrees Fahrenheit. The gage pressure is
___________?
A Less than 250
B Between 250 and 300
C Between 300 and 350
D More than 350
47. Refrigeration must be gas tight because?
A The system will gain moisture
B The unit will not work
C The gas is poisonous
D The liquid will leave the condenser at saturation
48. A refrigeration system uses R-12. The condensing temperature is 125 degrees Fahrenheit. The operating
pressure of the condenser should be _________?
A 140 PSIG
B 155 PSIG
C 169 PSIG
D 183 PSIG
49. The 1 3/8 inch non-ferrous piping used for R-22 is 60 feet long. There will be one (1) sight glass, two (2)
short radius ells, one (1) globe valve and one (1) long radius ell. The total equivalent length is?
A Less than 100 feet
B Between 100 and 150 feet
C Between 150 and 200 feet
D More than 200 feet
50. When a control mechanism is used on an air conditioning system, the simplest control action is
_________________?
A A switch
B Two position or on-off
C Proportioning
D The single-function on-off control
1 Exam Prep – Trane Reciprocating Refrigeration 9
51. A normal start-up sequence of an R-22 system is initiated at psig condensing pressure when
the motor starts to open the blades.
A 155
B 165
C 175
D 185
52. Starters that make use of separate circuits in the motor to reduce the starting current are called starters.
A Full winding
B Across-the-line
C Winding
D Part winding
53. Compound gauges used for refrigeration service should be calibrated from 0 psi pressure to no less
than psi above the normal working suction and discharge pressures of the system.
A 50 to 75
B 50 to 100
C 75 to 100
D 75 to 110
54. Refrigerant 12 and 22 are solvents.
A Poor
B Fair
C Good
D Excellent
55. The amount of friction loss in a water pipe is dependent upon the __________?
A Pipe size
B Pipe length
C The condition of the pipe and the velocity of the water
D The condition of the pipe, the course taken by the pipe run and the velocity of the water
56. The recommended action to take when a compressor freezes due to a damaged mechanism is to