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The condenser which is very expensive to clean and requires the tubes to be cleaned with acid and neutralized is the: Select one: a. shell and tube condenser b. shell and coil condenser c. double tube condenser d. baffle condensers e. evaporative condensers ANSWER VV b An evaporator that contains only a small amount of liquid refrigerant at any time is what type of evaporator? Select one: a. A multi coil evaporator b. Flooded evaporator c. All of the answers d. None of the answers e. Dry evaporator ANSWER VV e The thermostatic expansion valve operates on the principle of balancing: Select one: a. Condenser pressure against a return spring b. Condenser temperature against a return spring c. Evaporator temperature against a return spring d. Evaporator pressure against a return spring ¢. The vapor pressure in the fecler bulb against a return spring and the evaporator pressure ANSWER VV ¢ The two types of evaporators, dry evaporators and flooded evaporator differ principally in what respect? Sclect one: a. The size of the evaporator b. The type of refrigerant used c. The dry evaporator cannot cool liquids d. The field maintenance availability of the types e. The method of refrigerant circulation ANSWER VV e Which of the following refrigeration controls statement is false? Select one: a. The evaporator expansion valve limits the degree of evaporator pump down b. One of the most important secondary controls is the expansion valve c. Evaporalor pressure controls prevent the pressure from dropping below a set level d. Solenoid valves may control flow of refrigerant on multi-evaporator systems e. Bellows pressure in a water regulating valve is balanced by an adjustable spring ANSWER VV a c. In flooded chiller and during the high load some liquid refrigerant may leave the evaporator d. Finned tube evaporator are the only type evaporator that can be applicd as the dircet expansion evaporator e. Finned tube evaporators may be used in the large air conditioning systems ANSWER vvd When charging a refrigeration system it should be done: Select one: a. To the receiver b. With the compressor off c. To the condenser d. With the liquid line shutoff valve closed. e. With the cooling water shut off ANSWER VV d High head pressure in a refrigeration system usually indicates: Select one: a. The cooling water temperature is too low b. Broken plates in the compressor suction valves c¢. Broken plates in the compressor discharge valves d. Air or non-condensable gases in the system ¢, Lack of refrigerant in the system ANSWER Vv d When the chilled water temperature rises approximately 5-6°C above the set point of the control thermostat, the: Select one: a. Compressor will be shut down b. Condenser pump will be restarted c. Compressor will be restarted d. Cooling tower fan will be restarted e. Cooling tower fan will be shut down ANSWER VV A simple trap located in the suction line before the compressor that collects liquid, where it evaporates and returns to the compressor as a gas, is called: Select one: a. An accumulator b. A stop valve c. A distributor d. An oil separator e. A strainer-drier ANSWER VV a Which of the following statements about refrigeration pressure gages is truc’? Select one: a. Only one pressure gage is required for each system b. They indicate pressures and corresponding temperatures in a system. c. Permanently installed pressure gages shall be constructed for at least 1.5 times the design pressure d. Dials on refrigeration pressure gages do not indicate saturation temperature b. Lower noise levels. c. Align piping. d. Insulate piping and make the system more efficient. e. Increase longevity of the system. ANSWER VV b When pumping down a refrigeration system it is recommended to leave residual pressure in the system to prevent air being drawn in through minor leaks or compressor shaft seals. Select one: a. 7- 14 kPa b. 33 - 57 kPa c. 1-6kPa d. 25 -32 kPa e. 15-24 kPa ANSWER VV a The chilling coil in an automatic purger has a primary function to: Select one: a. Separate refrigerant vapor from the non-condensable gases to be purged. b. Lower the operating temperature of the purger. c. Increase the efficiency of the system. d. Keep the system cooling while being purged. c. Keep discharge through the coil at the lowest available suction pressure. ANSWER V / a Before charging a system which of the following needs to be done? Select one: a. All of the answers b. The required valves need to be opened ce. The interlocks need to be tested d. The controls need to be set e. The sequence of controls must be tested ANSWER VV a The ---------- ammonia is absorbed by the ---------- aqua. Select one: a. Vaporized, strong b. Fluid, hot c. Vaporized, weak d. Liquid, weak e. Liquid, strong ANSWER /V¥ ¢ Absorption refrigeration systems must be purged of: Select one: a. Air b. Nitrogen c. Non-condensable gases d. Ammonia vapor e. Condensable gases ANSWER VV ¢ c. The operating cycle in the system is continuous. ANSWER Vv b In an Ammonia Absorption System what is used as the absorbent? Sclect one: a. Water b. Air c. Ammonia d. Lithium Bromide e. Freon ANSWER VV a In the lithtum bromide absorption refrigeration system the generator is used to convert the ---- ---- solution to a ---------- solution. Select one: a. Hot, cold b. Black, white c. Weak, strong d. Cold, hot e. Strong, weak ANSWER VV ¢ In a closed tank that is partially filled with a salt solution at a temperature well below the boiling point of the solution: Select one: a. Some molecules of water vapor will actually be absorbed back into the solution. b. Some molecules of water vapor will actually escape from the solution. c. No molecules of water vapor will be able escape from the solution. d. No molecules of water vapor will be absorbed back into the solution. ¢. There will be a steady stream of water vapor molecules leaving and entering the solution. ANSWER VV ¢ When shutting down the lithium bromide refrigeration system for a weekend or less which of the following is a correct shutdown procedure? Select one: a. Close the manual steam or hot water supply valve b. Drain the cooling water circuit c. Turn off the air supply to the pneumatic control system d. Open all disconnect switches e. Service the purge pump ANSWER VV a In the Lithium Bromide system what is the function of the concentrator (regenerator)? Select one: a. To cool the refrigerant vapor. b. To increase the absorbency potential of used absorbent. c. To speed up the evaporation of the refrigerant. d. To exchange heat between the high temperature refrigerant vapor and the atmosphere. e. To cool the concentrated absorbent. ANSWER VV ¢ Ammonia systems are seldom used for air conditioning purposes in large building mainly because ammonia: Octal alcohol is added to the lithium bromide solution to: Select one: a. Help the lithium bromide solution absorb non-condensables b. Act as a dispersing agent c. Act as a drying agent d. Act as a wetting agent e. Help the lithium bromide solution absorb ammonia ANSWER VV d Refrigeration system designers consider the following rules per CSA B52: 1- System pressure? 2- How much refrigerant can leak’? 3- How much refrigerant is in the system? 4- How toxic is the refrigerant? 5- How flammable is the refrigerant? 6- What is the occupancy? Select one: ©. 2,4, 5,6 d. 1, 2, 3,4 e. 1,3,4 ANSWER V/V b CSA B82? classifies a refrigeration system as high pressure plant if its high side pressure is: Select one: a. Above 15 kPa b. Above 250 kPa c. Above 100 kPa d. Above 70 kPa e. Above 101.3 kPa ANSWER VV c Ammonia refrigeration systems over ----------- must be installed in class "T" machine rooms. Select one: a. LO kW b. 55 kW ec. 1STR d. 10 TR e.75kW ANSWER VV e Per CSA B52, the safety limit control set point for an ammonia refrigeration system not to be more than ---------- percentage of the high side safety valve. Select one: a. 10 c. 90 d. 70 e. 50 ANSWER V/V c The hazard degree of refrigeration plant is not depending on: Select one: a. Toxicity b. Leakage c. Complexity d. Pressure e. Flammability ANSWER VV ¢ A refrigeration environmental emergency is defined by -------------. Select one: a. CEPA b. CSA B52 c. ASME B31.5 d. TAR e. OSHA ANSWER VV a = requires owners to provide employees with a written emergency plan. Select one: a. OSHA b. CSA B52 c. ASME B31.5 d. IIAR, e. CEPA ANSWER VV b The relative humidity should be maintained between: Select one: a. 30% and 70% during the summer and the winter b. 25% and 60% during the summer c. 50% and 80% during the winter d. 20% and 60% during the winter e. 40% and 75% during the summer ANSWER VV a Using the Psychrometric chart, find the specific volume (in m3/kg) if the dry-bulb temperature is 28°C and the wet-bulb temperature is 21°C. Select one: a. 0.87 b. 0.94 . 0.96 d. 0.89 e.0.91 ANSWER VV a Air is approximately what composition by volume? Select one: a. 79% O2 and 21% N2 b. 79% N2 and 21% CO2 c. 79% CO2 and 21% 02 d. 79% T12 and 21% H20 vapor c. pressure below which water vapor will start to condense out of the air d. temperature at which water vapor will start to be absorbed into the air e. temperature at which water will start to evaporate ANSWER VV b Which law describes the existence of moisture in the air in vapor or evaporated state? Select one: a. Dalton's Law of Partial Pressures b. Newton's laws of gravity c¢. 2nd law of Thermodynamics d. Boyle's Ideal Gas Law e. Ist law of Thermodynamics ANSWER VV a What is wet-bulb depression? Select one: a. decrease in the absolute humidity b. decrease in relative humidity ¢. difference between the dry-bulb temperature and the wet-bulb temperature d. lowering of the thermometer bulb into water ¢. sum of the wet-bulb temperature and the dry-bulb temperature ANSWER VV ¢ Standard air is: Select one: a. the volume of | kg of air at ambient temperature and atmospheric pressure b. the volume of 1 kg of air at 15°C and 100 kPa c. the volume occupied by 1 kg of dry air at 21°C and atmospheric pressure at sea level or 101.325 kPa d. the mass of 1 cubic metre of air at atmospheric conditions ¢. the mass of 1 cubic meter of dry air at 20°C and atmospheric pressure ANSWER VV ¢ Air used for ventilating purposes in an office building should be kept within certain range of relative humidity as indicated below. (refer to the comfort chart) Select one: a. 10 to 30% b. 40 to 50% c. 30 to 50% d. 50 to 60% e. 30 ta 70% ANSWER V/V e Relative humidity is the amount of Select one: a. moisture contained in the air compared to the maximum amount of moisture the air is capable of holding at the stated temperature b. moisture contained in the air at 0 degrees C ¢. air contained in the air-moisture mixture compared to the maximum amount of air the air- mixture moisture is capable of holding at the stated temperature d. air compared to the amount of moisture in the air al any temperature e. moisture contained in the air compared to the maximum amount of moisture the air is capable of holding, air temperature being irrelevant ANSWER VV a 
