1 Exam Prep Trane Reciprocating Refrigeration Questions · 2018-03-29 · 1 Exam Prep Trane...

1 Exam Prep

Trane Reciprocating Refrigeration Questions Part 1

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. The condenser water of high efficiency forced or induced draft cooling towers will cool to a point of?

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 front seat 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 1OF 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 1

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 windingsare?

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

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 A Thermometer B A Thermostat C A Dry Bulb D A 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

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

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 ref rigerant-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

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

39. While troubleshooting a refrigeration system, Chilly Pete observes bubbles in the sight glass and determines the system needs refrigerant. Chilly Pete 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?


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

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

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 the compressor?

A Overhaul the compressor B Replace C Repair or replace D Clean and check

57. Bubbles in the sight glass and a lack of refrigerant indicate the?

A Discharge pressure is too high B Discharge pressure is too low C Suction pressure is too high D Suction pressure is too low

58. Given R12 at 196 PSIG, the temperature of saturated refrigerant in the receiver is?


59. Given R 12 at 181 PSIG. The refrigerant leaves the condenser at 124 degrees Fahrenheit. The refrigerant is subcooled?

A 4 degrees B 6 degrees C 8 degrees D 10 degrees?

60. A walk-in freezer uses R 22 refrigerant. The low pressure cutout is at 10 PSIG. To lower the temperature 6 degrees, the low pressure cutout must be set at?

A 6.8 B 5.8 C 7.9 D 9.0

61. The temperature is 16 degrees Fahrenheit. The contractor is using R 22. Suction pressure should be?

A 71 PSIA B 86 PSIA C 38 PS IA D 53 PSIA


62. Voltage readings were taken with the following results: 226V, 230V and 241 V.The percent of variance is?

A 1.5 B 2 C 3.3 D 3.7

63. A storage tank contains R 12. The outside air temperature is 130 degrees Fahrenheit. The gage pressure is?

A Less than 175 B Between 175 and 185 C Between 185 and 195 D More than 195

64. A refrigeration system uses R 22. The condensing temperature is 126 degrees Fahrenheit. The operating pressure of the condenser should be?

A 296 PSIG B 281 PSIG C 169 PSIG D 183 PSIG10

65. The 1 5/8 inch non-ferrous piping used for R 22 is 40 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

66. 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

67. 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



A 155 B 165 C 175 D 185

69. Damper control is adequate for condensing ambient air temperatures down to approximately degrees Fahrenheit.

A 50 B 45 C 40 D 35

70. 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

71. 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

72. 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

73. 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


74. Refrigerant 12 and 22 are solvents.

A Poor B Fair C Good D Excellent

75. 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

76. 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.

77. 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

78. The recommended action to take when a compressor freezes due to a damaged mechanism is to the compressor?

A Overhaul the compressor B Replace C Repair or replace D Clean and check

79. While troubleshooting a refrigeration system, Chilly Pete observes bubbles in the sight glass and determines the system needs refrigerant.. Chilly Pete 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


80. In a refrigeration system, bubbles in the sight glass and a lack of refrigerant indicate the?

A Discharge pressure is too high B Discharge pressure is too low C Suction pressure is too high D Suction pressure is too low

81. 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

82. The gage reading for R 12 at 124 degrees should be?

A 166.73 B 181.43 C 162.15 D 171.40

83. The contractor is reading 259.91 on the compound gage. The temperature must be lowered 18 degrees. Using R 22 the gage reading should be?

A 210.60 B 195.91 C 201.76 D 222.42

84. The contractor is installing a single phase magnetic starter. Voltage equal to line voltage between loads T-1 and T-2 means?

A The magnetic coil is energized and the starter main contacts are open B The magnetic coil is energized and the auxiliary contacts open C The starter main contacts are energized and the auxiliary contacts are closed D The magnetic coil is energized and the main contacts and auxiliary contacts are closed

85. Billy Joe obtained voltage readings of 230, 225 and 232. Billy Joe pondered and determined the voltage imbalance was?

A 1.75 percent B 1.31 percent C 17.46 percent D 2.941 percent


86. The R 22 discharge is 305 PSIG. The condenser pressure is 302 PSIG. Pressure at the expansion valve is 225 PSIG. The most probable cause is?

A Refrigerant overcharge B Improperly sized expansion valve C Improper superheat adjustment D Inoperative expansion valve

87. R22 is being sent from the evaporator to the compressor. The distance is 300 feet. The pressure drop is 2.0 psi. The copper line is 3 5/8 inches. The maximum tonnage is?

A 43.2 B 57 C 63 D 77.5

88. R22 is being delivered from the evaporator to the compressor. The distance is 360 inches. The pressure drop is 2.0 psi. The copper line is 2 5/8 inches. The maximum tonnage is?

A 43.5 B 57.4 C 63.5 D 92.5

89. The HE HEC250 compressor has a condensing temperature of 115 degrees F and a suction temperature of 30 degrees F. R22 is to be delivered 300 feet. When delivering liquid refrigerant from the receiver to the evaporator the maximum line size with the least pressure drop is?

A 1 5/8 at 2 psi B 1 3/8 at 4 psi C 1 3/8 at 5 psi D 1 1/8 at 8 psi

90. The suction temperature is 20 degrees F and the condensing temperature is 135 degrees F. R 22 is being moved from the evaporator to the compressor. The distance is 300 inches. The pressure drop is 2 psi. Using a 3 5/8 inch line, the corrected tonnage should be?

A 63 B 94.5 C 219 D 328.5

91. The gage reading is 10.182. Refrigerant 12 is being used. To lower the temperature 8 degrees the gage reading must be?

A 5.363 B 6.264 C 20.059 D 20.960


92. The gage reading is 337.25. Using R 22, the temperature is?

A 135 B 150 C 120 D 140

93. The controller containing a shaft with a series of cams is the?

A Potentiometer controller B Magnetic relay controller C Step controller D Proportional controller

Drawing 'Er Drawing '`C"

94. Which drawing is wired correctly for 230 volt full winding start?

A A B B C C D D

95. Given an absolute pressure reading of 24.878 pounds per square inch, a pressure gage will register how many pounds of pressure per square inch for saturated refrigerant-12?

A 10.182 B 11.243 C 12.340 D 13.471

96. The pressure gage registers pounds of pressure per square inch for saturated refrigerant -22 at 120 degrees Fahrenheit.

A 252.94 B 259.91 C 281.63 D 289.14


controller in a refrigeration system can consist of a shaft upon which is mounted a 97. The series of cams.

A Pressure B Proportional C Signal D Temperature

98. The pressure difference is measured by , when using oil pressure failure controls.

A Subtracting the oil pressure from the suction pressure B A time delay mechanism C Opposing bellows D A computer

99. Should the oil pressure fail to overcome opposing forces within when using the oil pressure failure control, the timer switch will open.

A One minute B Two minutes C 140 seconds D 160 seconds


A 165 B 170 C 175 D 180

101. The current starter makes use of separate circuits in the motor to reduce starting

A Across-the-line B Autotransformer C Part winding D Full winding

102. After sizing the liquid line, the line is next to be sized.

A Suction B Vapor C Hot gas discharge D Condenser drain


103. Assume a suction line is delivering R-22 vapor from evaporator to compressor. Given a 40 degree Fahrenheit suction and a 105 degree Fahrenheit condensing, the tonnage recommended at a pressure drop of 2.0 psi for a 1/2 inch copper tube (0.D. Type L) 30 feet long is?

A 2.1 B 1.1 C 0.9 D 0.4

104. The flame of a halide torch will turn if a small leak is present in a refrigeration system.

A Yellow B Bright orange C Dense blue D Green

105. Allow a refrigeration system to function normally for day(s) during the initial run-in period.

A 4 B 3 C 2 D 1

106.A gage is used to measure gas pressures both above and below atmospheric pressure.

A Compound B Discharge pressure C Head pressure D Liquid level

107. Given a temperature reading of minus 6 degrees Fahrenheit, a pressure gage will register pounds of pressure per square inch for saturated refrigerant-12.

A 6.264 B 7.195 C 8.158 D 9.153

108. At 124 degrees Fahrenheit, saturated refrigerant-12 has , expressed in pounds per square inch.

A An absolute pressure reading of 186.43 B An absolute pressure reading of 176.85 C A pressure gage reading of 166.73 D A pressure gage reading of 171.40


109. The refrigerant-22 at

A 138 B 140 C 142 D 144

110. The compressor.

pressure gage will register 337.25 pounds of pressure per square inch for degrees Fahrenheit.

is well suited to the stop-start, loading and unloading control of a reciprocating

A Duct thermostat B Pneumatic thermostat C Pressure controller D Step controller

111. The oil pump discharge pressure is sensed by one bellows while the suction pressure is sensed by another, when using?

A Oil pressure failure controls B High/low pressure controls C A diaphragm chamber D A pressure controller

112. Methods of air cooled condenser capacity control currently used in the United States include all of the following except controls.

A Damper B Fan cycling C Flood-back D Self-contained

113. In a refrigeration system, damper control is adequate for condensing a bient air temperature down to approximately degrees Fahrenheit.

A 30 B 35 C 40 D 45

114. Under normal conditions, with suction temperatures , it is good practice to use a total pressure drop of 2 psi when selecting R- 12 suction lines.

A Not exceeding 50 degrees Fahrenheit B In the 40 to 50 degree Fahrenheit range C Around 40 to 45 degrees Fahrenheit D In the "normal" range


115. Given a suction temperature of 10 and a conditioning temperature of 95, the suction line tonnage correction factor for R-22 is?

A 1.28 B 1.31 C 1.35 D 1.38

116. Assume a suction line is delivering R-22 vapor from evaporator to compressor. Given a 40 degree Fahrenheit suction and a 105 degree Fahrenheit condensing, the recommended tonnage at a pressure drop of 2.0 psi for a 3 and 5/8 inch copper tube (0.D. Type L) 100 feet long is?

A 53.5 B 77.5 C 113.0 D 141.0

117. The flame of a halide torch will turn if a large leak is present in a refrigeration system.

A Yellow B Bright orange C Dense blue D Green

118. After starting the initial run-in period for a refrigeration system, the amperage and voltage readings at each motor should be checked to make certain the system?

A Is cooling B Is operating at the condition established by the motor nameplate C Is not leaking D Has stabilized

119. Gauges used for refrigeration should be?

A Calibrated before being sent to the jobsite B Compound gauges C Calibrated to operate at 100 psi or greater D Calibrated to operate at any PSI

120. For liquid lines the recommended R-12 pressure drop is?

A 4 psi B 3 psi C 2 psi D 1 psi


120. The use of oxygen as a leak test gas may cause?

A Headaches B Itchy skin C A violent explosion D Nerve damage

121. The amount of superheat remains approximately constant to?

A Keep the system in balance B Prevent sludging of the compressor C Prevent liquid from entering the discharge line D Prevent liquid from entering the suction line

122. Most motors are rated on the basis of?

A Horsepower B Amperage C Temperature rise when running fully loaded D Voltage

123. Damper control is adequate for condensing ambient air temperatures do to approximately how many degrees Fahrenheit?

A 30 B 40 C 50 D 60

124. The superheat setting for most air conditioning systems is?

A 1OF B Approximately 8 to 11 F C 12F D Approximately 12 to 15 F

125. 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


126. 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

127. 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

128. 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

129. Because of very short piping and little resistance to spray water flow, the for an evaporative condenser is considerably lower than that of a cooling tower system of equal capacity.

A Brake differential B Enthalpy C Pump horsepower D Blowdown

130. Oil pressure failure controls operate using how many pressure sensitive lines?

A 1 B 2 C 3 D 4

131. The gage reading for R-12 at 40 degrees Fahrenheit is?

A 51.6 B 36.9 C 49.8 D 35.1


132. Which is not a method of air cooled condenser capacity control?

A Damper B Fan cycling C Flood-back D Blade modulation

133. When the relief valve is tapped into the condenser, some codes require the installation of a relief valve on the pressure side of the system.

A Low B High C Reverse D Forward

134. A proportional controller produces a control signal.

A Modulated B Vibratory C Differential D Magnified

135. Any increase in condensing temperature and pressure will cause a in evaporative condenser capacity when considering the wet bulb temperature of the air supply?

A Increase B Decrease C Reversal D Surcharge

136. Using R-22 vapor from the evaporator to the compressor at 40 ° F suction and 105 ° F condensing, with 300 feet of developed length, a 2 PSI drop, a 3 5/8 inch pipe should be capable of supporting how many tons?

A 43.2 B 52.5 C 87.5 D 63.0

137.R-22 at 48 degrees Fahrenheit has a gage reading of?

A 95.4 B 80.7 C 78.2 D 78.5


138. A device used to measure gas pressures both above and below atmospheric pressure is a/an?

A Compound gage B Bellows gage C Head pressure gage D Suction pressure gage

139. R-502 at 46 degrees Fahrenheit has a gage reading of?

A 74.3 B 89.0 C 82.3 D 92.1

140. When making copper-to-steel joints, the contractor should use?

A Sil-fos B Silver solder C Crocus solder D Acid flux

141. A straight induction. motor is commonly known as a/an?

A Discharge induction motor B Semi-hermetic motor C Hermetic motor D Straight induction motor

142. A main control for air cooled condensers is through the use of a control.

A Damper B Flyback C Multiflex D Constant pressure

143. The heat required to change a liquid to a gas is the?

A Latent heat of vaporization B Latent heat of fusion C Latent heat of fission D Latent heat of evaporation


144. Useable oil pressure is determined by?

A Bore stroke analysis B The size of the piston and the force of the ram C Oil pressure plus suction pressure D Oil pressure minus suction pressure

145. A NEMA rated enclosed motor with a Class Insulation factor of F would have a maximum surface temperature of degrees Fahrenheit.

A 273 B 265 C 309 D 335

146. Leak testing should be?

A An on-going process B Done before the pipe is insulated C The first check of the system D Done visually prior to start-up

147.Normally the solenoid oil valves are controlled by?

A The multi-stage electric thermostat B The de-energizing valve C A solenoid valve timing switch D A hemi-stat reversing control valve

148. The minimum hot gas velocity for the vertical riser should be not less than feet per minute.

A 500 B 1,000 C 1,500 D 2,000

149. According to Trane Reciprocation Refrigeration, when adding compressor oil, the contractor should?

A Use one additional pint of refrigerant for each ten pounds of oil B Use one additional pint of oil for each ten pounds of refrigerant C Pump the oil into the compressor crankcase while the system is shutdown D Check to see that the oil is filling the sight glass


150. The hot gas line is the line?

A Compressor to the condenser B Condenser to the evaporator C Evaporator to the compressor D Compressor to the evaporator

151. When needing to install a 15 ton unit using R-22, at 100 feet developed length with a 3 psi drop from the receiver to the evaporator, the size Type "L" copper line to use with a suction of 40F and 105 F condensing is inches.

A 7/8 B 1 C 1 1/8 D 13/8

152. A proportional controller produces a?

A Modulated signal B Calibrated signal C Pneumatic action D Piston drive

153.The amount of friction loss within a pipe is dependent upon?

A The condition of the pipe and the velocity of the water B The type of pipe and the velocity of the water C The size of the pump and the distance of the flow D Rate of flow and the condition of the pump

154. According to Trane Reciprocating Refrigeration, which of the following should never be used as a test gas?

A Dry nitrogen B Oxygen C Krypton D Argon

155. The looping of hot gas from the compressor is usually done by a degree loop.

A 45 B 90 C 180 D 360


156. Using R-22 with 25 tons and a 1 5/8 inch line, the gas velocity in feet per minute is?

A 4,000 B 6,000 C 1,000 D 2,000

157.The equivalent length in feet is 50. R-22 is being used from the evaporator to the compressor. The suction is 35 degrees Fahrenheit and 115 degrees Fahrenheit condensing. The pressure drop is 2.0 psi. The minimum tonnage using a 7/8 inch Type "L" copper line is?

A 3.4 B 3.8 C 3.52 D 38.08

158. Once the compressor is fully unloaded, any further system load reduction causes the?

A System to overheat and shut down B Compressor suction pressure and temperature to fall accordingly C TI-IX valve to automatically close and open D Oil pressure to decrease and the system to chug

159. The suction line is from the?

A Evaporator to the compressor B Condenser to the evaporator C Compressor to the condenser D Compressor to the evaporator

160. The service technician notices the gage pressure for Refrigerant 22 is 243 degrees. The temperature should be how many degrees Fahrenheit?

A 114 B 115 C 116 D 117

161. To stabilize the suction pressure and temperature throughout, compressors used in large systems are generally equipped with cylinder?

A Sequence monitoring B Unloading control C Timing mechanisms D Withdrawal blocks


162. One of the nice things about a trap is?

A The filter effect on the fluid B The aid in allowing the oil to start its climb up the suction and hot gas risers C The minimum horizontal dimension required for cutting down the elbows D The accumulation of oil drained from the hot gas riser

163. When joining copper-to-steel the best solder to use is?

A Hard B Soft C Silver D Lead

164. Most air conditioning systems use a superheat setting of approximately degrees Fahrenheit. A 12 to 15 B 15 to 18 C 18 to 21 D 21 to 24


Part 2

1. On a vapor compression refrigeration system, the function of the hot gas line or compressor discharge line is to:

A. Conduct compressed refrigerant gas and entrained oil from the compressor to the condenser. B. Conduct compressed refrigerant gas from the compressor to the condenser and prevent entrained oil from entering the condenser. C. Conduct compressed refrigerant gas from the compressor to the inlet side of the evaporator. D. Provide compressor capacity control during periods of part load capacity. E. Conduct liquid refrigerant from the condenser to the expansion valve.

2. According to Trane Reciprocating Refrigeration Manual, in a vapor-compression refrigeration system the liquid line is the connection between

A. The compressor and the condenser. B. The evaporator and the condenser. C. The expansion valve and the condenser. D. The evaporator and the compressor. E. The hot gas by-pass valve and the condenser.

3. According to Trane Reciprocating Refrigeration Manual, the actual capacity of a reciprocating refrigeration compressor in volume of gas pumped as compared to its theoretical capacity is called

A. Compression ratio. B. Cfm displacement C. Volumetric efficiency D. Displacement volume E. Refrigeration effect

4. According to the Trane Reciprocating Refrigeration Manual, a compressor which is driven by an external power source is known as a/an compressor.

A. Open B. Hermetic C. Semi-hermetic D. Centrifugal E. Rotary


5. According to Trane Reciprocating Refrigeration Manual, a direct expansion evaporator coil is classified as a:

A. Flooded evaporator. B. Dry evaporator C. Shell and tube evaporator D. High capacity type evaporator E. Liquid refrigerant evaporator

6. The maximum acceptable velocity range for refrigerant suction and discharge lines is FPM.

A. 100 B. 300 C. 1,000 D. 4,000 E. 6,000

7. Reciprocating compressors that provide for variable capacity reduction are designed and equipped with:

A. Variable speed motors B. Modulating refrigerant flow to cylinders C. Hermetic sealed motors E. Ring type suction valves

8. A device for directly condensing hot gas refrigerant by spraying water over the surface of the condensing coils is referred to a/an

A. Cooling tower B. Air cooled condenser C. Water cooled condenser D. Evaporative condenser E. Evaporator

9. Frost on the outlet of a liquid line filer-drier is a symptom of

A. High discharge pressure B. Excessive subcooling C. Refrigerant undercharge D. Refrigerant overcharge E. A clogged filter-drier


10. A vessel or arrangement of piping or tubing in which vaporized refrigerant is liquefied by the removal of heat is a/an

A. Liquid receiver B. Evaporator C. Condensing unit D. Condenser E. Compressor

11. A/an is a vessel permanently connected to refrigeration system by inlet and outlet pipes for

storage of a liquid refrigerant.

A. Container B. Evaporator coil C. Liquid receiver D. Condenser coil E. Intercooler

12. To minimize the transmission of noise due to the pulsation of the refrigerant hot gas discharge from a reciprocating compressor. A should be installed.

A. Damper B. Muffler C. Filter-drier D. Expansion valve E. Liquid-to-suction heat exchanger

13. According to Trane Reciprocating Refrigeration Manual, when hot gas bypass capacity control is applied to a system with a direct expansion coil and this system is designed to operate with 100% outdoor air entering the evaporator coil, the temperature of the air entering the coil must never fall below the

A. Design saturated suction temperature of the refrigerant leaving the evaporator coil B. Condensing temperature of the hot gas refrigerant entering the condenser C. Design room temperature. D. Design leaving air temperature of the evaporator coil

E. Design entering air temperature of the evaporator coil


14. Given: a refrigeration system with an air cooled condenser is charge with 14 pounds of R-12. The system operates at a condensing temperature of 120 F. What is the operating pressure of the condenser? Select the closet answer.

A. 117 PSIG B. 143 PSIG C. 158 PSIG D. 208 PSIG

15. According to Trane Reciprocating Refrigeration Manual, an open type refrigeration compressor is

A. Driven by an external power source B. Driven by a hermetically sealed motor C. Driven at a very high speed D. Required for air conditioning systems above 25 tons E. Not used in comfort air conditioning systems

16. According to Trane Reciprocating Refrigeration Manual, the head pressure of an R-22, air cooled condenser is 220 PSIG. If the refrigerant leaves the condenser at 104 F, it is subcooled.

A. 0 degree F B. 2 degree F C. 4 degree F D. 6 degree F E. 8 degree F

17. According to Trane Reciprocating Refrigeration Manual, the pressure drop in a refrigerant suction line conveying R-22 should not exceed psi.

A. 1 B. 2 C. 3 D. 4 E. 5

18. According to Trane Reciprocating Refrigeration Manual, the gage pressure of saturated refrigerant R-22 at

40 F is . Select the closest answer.

A. 69 psi B. 83 psi C. 96 psi D. 121 psi E. 137 psi


Part 1 ANSWER KEY

1 C Trane Reciprocating Refrigeration 30

2 A Trane Reciprocating Refrigeration 34



5 D Trane Reciprocating Refrigeration 123

6 B Trane Reciprocating. Refrigeration 40






12 B Trane Reciprocating Refrigeration 61



































231 + 227 + 233 + 3 = 230.3

231 - 230.3 = .66 230.3 - 227 = 3.33 233 - 230.3 = 2.66

.66 + 3.33 + 2.66 + 460.6% Yields 1.44





60 + 2.7 + (2 X 3.2) + 102 + 2.2 = 173.3













61

62

D

D

Trane Reciprocating Refrigeration

Trane Reciprocating Refrigeration

226 + 230 + 241 + 3 = 232.3

(232.3 - 226) + (232.3 - 230) + (241 232.3)

6.3 + 2.3 + 8.7 = 17.3

4

124

17.3 + (2 X 232.3) % Yields 3.7




40 + 3 +(2 X 3.8)+ 115 + 2.6 = 168.2





















230 + 225 + 232 ÷ 3 = 229

(230 - 229) + (230 - 229) + (232 - 229)

1+4+3=8


8 + 458% is 1.746 = 1.75




360 + 12 = 30'

89 B Trane Reciprocating Refrigeration 14/91





94 C Trane Reciprocation Refrigeration 61


























11 9 B Trane Reciprocating Refrigeration 71


























145 C Trane Reciprocating Refrigeration - 59





















Part 2

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