Which of the following is not a step in the seasonal pre start service?
a) clean all cooling and chilled water strainers
b) add water treatment chemicals
c)...
Which of the following is not a step in the seasonal pre start service?
Which of the following is NOT a result of having noncondensable gases in the absorption systems?
Which of the following is NOT a result of having noncondensable gases in the absorption systems?
a) Corrosion
b) Oxidation of Lithium Bromide
c)...
Concentration of the Lithium Bromide can be most easily controlled by which of the following means?
Concentration of the Lithium Bromide can be most easily controlled by which of the following means?
a) Controlling the volume of water sprayed into...
The concentration of Lithium Bromide in an absorption refrigerating system will change during which of the following steps?
The concentration of Lithium Bromide in an absorption refrigerating system will change during which of the following steps?
a) Going through the expansion...
When the temperature of a solution increases, which of the following statements is true?
When the temperature of a solution increases, which of the following statements is true?
a) The vapour pressure is high
b) Less water molecules leave...
This occurs when the temperature of a strong but still unsaturated solution is lowered so far that its salt concentration exceeds the maximum concentration possible at the lower temperature.
This occurs when the temperature of a strong but still unsaturated solution is lowered so far that its salt concentration exceeds the maximum concentration...
Most absorbency systems are put in place where there is cheap excess or waste heat available. What is this heat primarily used for?
Most absorbency systems are put in place where there is cheap excess or waste heat available. What is this heat primarily used for?
a) To pressurize...
What is the function of the concentrator (generator)?
What is the function of the concentrator (generator)?
a) To cool the refrigerant vapour
b) To increase the absorbency potential of used Lithium Bromide
c)...
The absorber is equipped with a pump for which of the following reasons?
The absorber is equipped with a pump for which of the following reasons?
a) To force water into a finely divided state
b) To keep the cycle pressure...
Which of the following statements about Lithium bromide systems is false?
Which of the following statements about Lithium bromide systems is false?
a) Lithium bromide solution has the ability to absorb water vapour readily.
b)...
In order to lower the boiling point of the refrigerant it is important that the system maintain
In order to lower the boiling point of the refrigerant it is important that the system maintain
a) an extremely high vacuum
b) very high pressure
c)...
In a Lithium Bromide System which of the following is the refrigerant?
In a Lithium Bromide System which of the following is the refrigerant?
a) Lithium Bromide
b) Ammonia
c) Freon-22
d) Water
e) None of the above
...
In comparing absorption and compression systems which of the following comparisons is true?
In comparing absorption and compression systems which of the following comparisons is true?
a) Pumps in absorption systems require more electrical...
Ammonia systems are seldom used for air conditioning purposes in large buildings mainly because
Ammonia systems are seldom used for air conditioning purposes in large buildings mainly because
a) ammonia systems require too much maintenance
b)...
Which of the following is not found on the low side of an ammonia system?
Which of the following is not found on the low side of an ammonia system?
a) Evaporator
b) Generator
c) Absorber
d) Cooling water
e) Low pressure...
In an Ammonia Absorption System what is used as the absorbent?
In an Ammonia Absorption System what is used as the absorbent?
a) Ammonia
b) Air
c) Lithium Bromide
d) Water
e) Freon
Answer: ...
Checking the condition of electrical starters and contactors is categorized under which of the following maintenance schedules?
Checking the condition of electrical starters and contactors is categorized under which of the following maintenance schedules?
a) Daily maintenance
b)...
A system of regularly scheduled inspections and lubrications along with the adjustments, minor parts replacement and minor repairs necessary to keep the refrigerating plant and equipment in good operating condition is defined as
A system of regularly scheduled inspections and lubrications along with the adjustments, minor parts replacement and minor repairs necessary to keep...
If a compressor fails to start but the motor is running, which of the following could be a cause?
If a compressor fails to start but the motor is running, which of the following could be a cause?
a) The control circuit is open
b) The compressor...
The safety control in a centrifugal compressor which ensures the compressor to only be started under a no load condition is called
The safety control in a centrifugal compressor which ensures the compressor to only be started under a no load condition is called
a) low oil pressure...
A centrifugal compressor refrigerating system can be stopped simply by pressing the stop button unless which of the following circumstances is true?
A centrifugal compressor refrigerating system can be stopped simply by pressing the stop button unless which of the following circumstances is true?
a)...
Which of the following steps is NOT part of the startup procedure of centrifugal compressor refrigerating systems.
Which of the following steps is NOT part of the startup procedure of centrifugal compressor refrigerating systems.
a) Check the refrigerant levels.
b)...
To avoid liquid slugging in a direct expansion evaporator after shutting down a reciprocating or rotary compressor refrigerating system which of the following measures needs to be taken?
To avoid liquid slugging in a direct expansion evaporator after shutting down a reciprocating or rotary compressor refrigerating system which of the...
Which of the following steps is not a step in the startup of a reciprocating or rotary compressor refrigerating system?
Which of the following steps is not a step in the startup of a reciprocating or rotary compressor refrigerating system?
a) Check oil level in the...
Oil added to refrigeration compressors
Oil added to refrigeration compressors
a) is done when the compressor discharge valve is closed
b) is done with a vacuum on the crankcase
c) is done...
It is very important to open oil drain valves and plugs in the crankcase for which of the following reasons?
It is very important to open oil drain valves and plugs in the crankcase for which of the following reasons?
a) The oil is very hot.
b) The oil is...
Which of the following statements about adding oil to a system is true?
Which of the following statements about adding oil to a system is true?
a) Oil is added by charging it into the crankcase.
b) Because the crankcase...
What can cause a high discharge pressure with refrigeration systems?
What can cause a high discharge pressure with refrigeration systems?
a) low evaporator level
b) too much cooling water to the condenser
c) over-purging...
When initially charging a refrigeration system
When initially charging a refrigeration system
a) it must be done with the liquid line shutoff valve open
b) it is done with a liquid refrigerant
c)...
When charging a refrigeration system it
When charging a refrigeration system it
a) should be done to the condenser
b) should be done with the cooling water shut off
c) should be done to...
Charging a refrigeration system
Charging a refrigeration system
a) is done with the expansion valve closed
b) is done by adding refrigerant between the liquid shutoff valve and...
The liquid line shutoff valve is
The liquid line shutoff valve is
a) used when purging the system
b) a regulating valve
c) used to relieve pressure
d) required to be closed when...
Frost formation on the suction line indicates what?
Frost formation on the suction line indicates what?
a) Moisture in the system
b) "Copper-Plating" on the bearings and compressor exhaust valve
c)...
The initial refrigerant charge is given where on the system?
The initial refrigerant charge is given where on the system?
a) The high side of the system
b) The low side of the system
c) The evaporator
d) The...
Before charging a system which of the following needs to be done?
Before charging a system which of the following needs to be done?
a) Interlocks need to be tested
b) Controls need to be set
c) Controls need to...
A sulphur candle is a test for
A sulphur candle is a test for
a) freon leaks
b) ammonia leaks
c) air leaks
d) vacuum seal
e) CFC leaks
Answer: ...
Which of the following is not a recommended step for the procedure in which dry nitrogen is used for a system leak test?
Which of the following is not a recommended step for the procedure in which dry nitrogen is used for a system leak test?
a) Remove controls and relief...
Leak testing on a refrigeration system
Leak testing on a refrigeration system
a) is done with a sulphur stick for freon refrigerant
b) is done with litmus paper for freon
c) is done with...
Leak testing for tightness under pressure of a refrigeration system
Leak testing for tightness under pressure of a refrigeration system
a) is done by the manufacturer
b) is done with oxygen
c) is done with ammonia
d)...
When using lighted sulphur candles to test for ammonia leaks in a refrigeration system, the presence of ammonia will be indicated by
When using lighted sulphur candles to test for ammonia leaks in a refrigeration system, the presence of ammonia will be indicated by
a) a cloud of...
The chilling coil in an automatic purger has a primary function to
The chilling coil in an automatic purger has a primary function to
a) lower the operating temperature of the purger
b) keep the system cooling while...
Which of the following statements about Manual Purging Systems is false?
Which of the following statements about Manual Purging Systems is false?
a) They must be operated on a regular schedule.
b) The receiver and condenser...
Higher than normal head pressure is undesirable for all of the following reasons except
Higher than normal head pressure is undesirable for all of the following reasons except
a) it increases power consumption
b) it decreases condenser...
The emergency discharge line in a refrigeration system
The emergency discharge line in a refrigeration system
a) is located only on the condenser
b) should have a shut-off valve outside the building
c)...
Emergency discharge is used to counter which of the following problems?
Emergency discharge is used to counter which of the following problems?
a) Dangerously low system pressures
b) Toxic refrigerant leaks
c) Combustion...
A direct expansion type evaporator that has more than 1 refrigerant circuit in it requires what to have even refrigerant flow in each circuit?
A direct expansion type evaporator that has more than 1 refrigerant circuit in it requires what to have even refrigerant flow in each circuit?
a)...
Which of the following statements about pressure gages is true?
Which of the following statements about pressure gages is true?
a) They indicate pressures and corresponding temperatures in a system.
b) Dials on...
The accessory which maintains efficient heat transfer by collecting oil that coats the tubes of the condenser is called
The accessory which maintains efficient heat transfer by collecting oil that coats the tubes of the condenser is called
a) a strainer
b) a strainer-drier
c)...
Moisture in a system can result in which of the following?
Moisture in a system can result in which of the following?
a) formation of ice
b) acid formation
c) corrosion
d) deterioration of motor insulation
e)...
Which of the following pipe joints should be used for high pressure 1 1/4 inch or smaller piping?
Which of the following pipe joints should be used for high pressure 1 1/4 inch or smaller piping?
a) welded
b) screwed
c) soldered
d) flared
e) none...
The function of vibration absorbers is to
The function of vibration absorbers is to
a) lower noise levels
b) reduce pipe hammer
c) increase longevity of the system
d) insulate piping and...
A chemical dot placed under the glass lens of a sight glass which is exposed to the liquid serves what function?
A chemical dot placed under the glass lens of a sight glass which is exposed to the liquid serves what function?
a) To monitor liquid flow
b) To...
Which of the following statements about strainers is false?
Which of the following statements about strainers is false?
a) The strainer is installed in the suction line.
b) Piping must be disconnected to clean...
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
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...
The control which is replacing suction throttling and operates by swirling the refrigerant in the same direction as the compressor impeller, resulting in a reduction of power required by the compressor is which of the following controls?
The control which is replacing suction throttling and operates by swirling the refrigerant in the same direction as the compressor impeller, resulting...
The type of operation which stops the compressor when the desired low temperature of the substance to be cooled is reached and starts the compressor up again when the temperature rises to a set level is called
The type of operation which stops the compressor when the desired low temperature of the substance to be cooled is reached and starts the compressor...
Which of the following statements about evaporator dampers is true?
Which of the following statements about evaporator dampers is true?
a) These dampers decrease the resistance to the passage of air.
b) When the damper...
Sectional evaporators control the capacity of the evaporator by which of the following means?
Sectional evaporators control the capacity of the evaporator by which of the following means?
a) Varying the quantity of air being cooled passing...
One method of controlling the capacity of reciprocating compressors is to bypass the discharge from one or more cylinders back to the suction side of the compressor. The control is called
One method of controlling the capacity of reciprocating compressors is to bypass the discharge from one or more cylinders back to the suction side of...
In a system controlled by a high pressure float valve insufficient liquid will cause which of the following results?
In a system controlled by a high pressure float valve insufficient liquid will cause which of the following results?
a) automatic system shut down
b)...
The simple control which restricts the flow of liquid from the condenser to the evaporator and maintains a pressure difference between the two units by using a considerable pressure drop resulting from resistance between the devices length and small bore is called
The simple control which restricts the flow of liquid from the condenser to the evaporator and maintains a pressure difference between the two units...
Which control is used to maintain a constant level of liquid refrigerant in a flooded evaporator in the liquid reserve tank?
Which control is used to maintain a constant level of liquid refrigerant in a flooded evaporator in the liquid reserve tank?
a) thermostatic expansion...
Which of the statements about automatic expansion valves is false?
Which of the statements about automatic expansion valves is false?
a) The valve maintains constant pressure in the evaporator during compressor operation...
The most widely used refrigerant control which consists of a bellows or a diaphragm chamber connected to a temperature sensing bulb by means of a small capillary tube is a/an
The most widely used refrigerant control which consists of a bellows or a diaphragm chamber connected to a temperature sensing bulb by means of a small...
Oil pressure failure switches are used to perform which of the following functions?
Oil pressure failure switches are used to perform which of the following functions?
a) Keep oil from freezing at low pressure.
b) Prevent compressor...
The safety control which uses a current transformer with a resistor in the motor circuit is known as
The safety control which uses a current transformer with a resistor in the motor circuit is known as
a) high motor temperature cutup
b) low oil sump...
Which of the following statements about flow switches is false?
Which of the following statements about flow switches is false?
a) They are used on chilled water.
b) They are used as lockout switches when flow...
Safety controls serve what function?
Safety controls serve what function?
a) They stop operation if the temperature gets too high.
b) They stop operation when the pressure gets too high.
c)...
In many cases evaporator pressure must not be allowed to drop below a certain level to prevent which of the following results?
In many cases evaporator pressure must not be allowed to drop below a certain level to prevent which of the following results?
a) frosting of coils
b)...
Which of the following actuating control valves is electromagnetically operated?
Which of the following actuating control valves is electromagnetically operated?
a) Thermostat valve
b) Fluid expansion regulator valve
c) Evaporator...
The operating control which consists of a hygroscopic element made of material similar to multiple strands of human hair is called a
The operating control which consists of a hygroscopic element made of material similar to multiple strands of human hair is called a
a) humidistat
b)...
Which of the following statements about pressure stats is false?
Which of the following statements about pressure stats is false?
a) The control is connected to the suction line of the compressor.
b) The control...
The operating control which uses a bimetal element is a
The operating control which uses a bimetal element is a
a) fluid expansion actuating control
b) pressure actuated control
c) humidity actuated control
d)...
Starting, stopping or unloading of the compressor is usually done by all of the following operating controls except
Starting, stopping or unloading of the compressor is usually done by all of the following operating controls except
a) temperature actuated control
b)...
The purpose of a condenser in a refrigeration system is
The purpose of a condenser in a refrigeration system is
a) to remove the sensible heat from the refrigerant
b) to remove the latent heat from the...
Defective condenser operation is a result of the presence of all of the following except
Defective condenser operation is a result of the presence of all of the following except
a) scale forming chemicals
b) dirty cooling water
c) noncondensible...
The common types of water-cooled condensers used in refrigeration systems are:
The common types of water-cooled condensers used in refrigeration systems are:
1. the shell and tube
2. the shell and coil
3. the double tube
4. the...
The amount of water used in an evaporative condenser is only a small percentage of that used in a water condenser of the same capacity. This is due primarily to what?
The amount of water used in an evaporative condenser is only a small percentage of that used in a water condenser of the same capacity. This is due...
The condenser which is very expensive to clean and requires the tubes to be cleaned with acid and neutralized is the
The condenser which is very expensive to clean and requires the tubes to be cleaned with acid and neutralized is the
a) shell and tube condenser
b)...
Which of the following statements about double tube condensers is true?
Which of the following statements about double tube condensers is true?
a) It consists of two separate tubes side by side.
b) It cannot be used with...
Air-cooled condensers of large capacity are found mainly in which of the following locations?
Air-cooled condensers of large capacity are found mainly in which of the following locations?
a) roof tops
b) closed rooms with low air circulation
c)...
Which of the following statements about the shell and tube evaporator type is false?
Which of the following statements about the shell and tube evaporator type is false?
a) It is also known as a chiller.
b) This type of evaporator...
An evaporator which can easily be cleaned and defrosted manually without interrupting the cooling process is which type of evaporator?
An evaporator which can easily be cleaned and defrosted manually without interrupting the cooling process is which type of evaporator?
a) Bare finned
b)...
The evaporator which increases heat exchange by crimping thin metal plates to its form is which type of evaporator?
The evaporator which increases heat exchange by crimping thin metal plates to its form is which type of evaporator?
a) Plate surface
b) Bare tube
c)...
Refrigerant evaporators
Refrigerant evaporators
a) are only used in ammonia systems
b) are part of the high side of the system
c) are used to transfer oil
d) are only used...
An evaporator that contains only a small amount of liquid refrigerant at any time is what type of evaporator?
An evaporator that contains only a small amount of liquid refrigerant at any time is what type of evaporator?
a) Dry evaporator
b) Flooded evaporator
c)...
The two types of evaporators, dry evaporators and flooded evaporators differ principally in what respect?
The two types of evaporators, dry evaporators and flooded evaporators differ principally in what respect?
a) the dry evaporator cannot cool liquids
b)...
In rotating mechanical seals the sealing ring is held in position by
In rotating mechanical seals the sealing ring is held in position by
a) a nut, bolt, and washer
b) centrifugal force
c) oil suction
d) high pressure...
A typical stationary crankshaft seal consisting of a metallic bellows soldered at one end to a ring (seal nose) which bears either against a shoulder on the shaft or against a seal ring on the shaft is called a
A typical stationary crankshaft seal consisting of a metallic bellows soldered at one end to a ring (seal nose) which bears either against a shoulder...
Pistons and connecting rods are found in which of the following types of compressors?
Pistons and connecting rods are found in which of the following types of compressors?
a) Reciprocating
b) Rotary
c) Centrifugal
d) Both Rotary and...
Refrigerant compressors
Refrigerant compressors
a) must have inter-coolers
b) could be a centrifugal type
c) are of the positive displacement type only
d) are used with...
Piston displacement is defined as
Piston displacement is defined as
a) the distance along which the piston travels
b) the cylinder bore
c) the volume of refrigerant that can be circulated...
For a Helical Rotor Design rotary compressor which of the following statements is true?
For a Helical Rotor Design rotary compressor which of the following statements is true?
a) The compressor consists of 3 opposing grooved rotors.
b)...
In a rotating vane design rotary compressor, a good seal is maintained between the vanes and the cylinder by
In a rotating vane design rotary compressor, a good seal is maintained between the vanes and the cylinder by
a) centrifugal force
b) the oil
c) high...
One negative factor of Hermetic type reciprocating compressors is
One negative factor of Hermetic type reciprocating compressors is
a) the compressor and motor are mounted within the same housing
b) the motor is...
Which of the following compressor types uses impellers to draw in vapour?
Which of the following compressor types uses impellers to draw in vapour?
a) Centrifugal compressors
b) Rotary compressors
c) Reciprocating Compressors
d)...
In a refrigeration system, the purpose of the compressor is to
In a refrigeration system, the purpose of the compressor is to
a) establish two pressure levels
b) reject the heat from the system
c) absorb the...
Which of the following is the compressor responsible for doing?
Which of the following is the compressor responsible for doing?
i) Maintains a high pressure in the condenser
ii) Maintains a low pressure in the...
Which of the following is not a function of the compressor in a refrigeration system?
Which of the following is not a function of the compressor in a refrigeration system?
a) draw low pressure refrigerant out of the evaporator
b) draw...
In actual systems there will be a gradual pressure drop through each side of the system due to
In actual systems there will be a gradual pressure drop through each side of the system due to
a) the economiser
b) friction in the evaporator, condenser,...
Which of the following is a result of an economiser on the refrigeration system?
Which of the following is a result of an economiser on the refrigeration system?
a) an intercooling effect on the compressor
b) reduction of the...
Which of the following statements about the economizers is false?
Which of the following statements about the economizers is false?
a) It controls the flow of liquid refrigerant from the low pressure evaporator...
Which of the following is NOT an advantage of a factory assembled packaged refrigerant?
Which of the following is NOT an advantage of a factory assembled packaged refrigerant?
a) Components are designed to match each other.
b) Parts...
Refrigerant evaporators
Refrigerant evaporators
a) always have the refrigerant on the shell side
b) are located between the expansion valve and the receiver
c) may have...
The type of brine used for skating and hockey rink refrigeration systems is usually
The type of brine used for skating and hockey rink refrigeration systems is usually
a) calcium sulphate
b) calcium chloride
c) calcium carbide
d)...
Which of the following statements about a system that circulates warm brine or water back to a chiller tank is true?
Which of the following statements about a system that circulates warm brine or water back to a chiller tank is true?
a) The system is a direct refrigeration...
The primary difference between direct and indirect refrigeration systems is the
The primary difference between direct and indirect refrigeration systems is the
a) type of heat transfer medium
b) type of refrigerant
c) evaporator...
For a direct expansion system which of the following statements is true?
For a direct expansion system which of the following statements is true?
a) The evaporator in this system is never in direct contact with the material...
Refrigerant condensers
Refrigerant condensers
a) are always water cooled
b) cool the gas refrigerant discharged from the compressor
c) have a safety valve
d) remove sensible...
A purpose of a liquid refrigerant control or regulating valve is
A purpose of a liquid refrigerant control or regulating valve is
a) to drain the receiver
b) to regulate the refrigerant flow to the evaporator
c)...
The temperature in the evaporator
The temperature in the evaporator
a) depends on pressure in the receiver
b) will decrease when the compressor stops
c) depends on the pressure in...
Which of the following is NOT a component of the low pressure side of the system?
Which of the following is NOT a component of the low pressure side of the system?
a) compressor discharge
b) evaporator
c) downstream side of the...
Raising the condensing point (saturation temperature) of the refrigerant vapour above the temperature of the cooling medium is the function of the
Raising the condensing point (saturation temperature) of the refrigerant vapour above the temperature of the cooling medium is the function of the
a)...
Which of the following are principal parts in a closed cycle compression refrigeration system?
Which of the following are principal parts in a closed cycle compression refrigeration system?
i) Absorber
ii) Evaporator
iii) Compressor
iv) Condenser
a)...
Freon 22 refrigerant
Freon 22 refrigerant
a) is not miscible with oil
b) is mostly used in packing plants
c) is corrosive on copper
d) is corrosive on aluminum
e) is a...
Molecular mass is a dependent factor in which of the following physical properties?
Molecular mass is a dependent factor in which of the following physical properties?
a) miscibility
b) leakage tendency
c) toxicity
d) flammability
e)...
Ammonia is the only commonly used refrigerant which has the physical property of
Ammonia is the only commonly used refrigerant which has the physical property of
a) miscibility
b) enthalpy
c) flammability
d) density
e) low condensing...
Which of the following is not a physical property of refrigerants?
Which of the following is not a physical property of refrigerants?
a) Toxicity
b) Odour
c) Leakage tendency
d) Density
e) Explosiveness
Answe...
The ability of a refrigerant to be dissolved into oil and vice versa is called
The ability of a refrigerant to be dissolved into oil and vice versa is called
a) moisture reaction
b) enthalpy
c) density
d) leakage tendency
e)...
The latent heat of fusion of ice
The latent heat of fusion of ice
a) is the sensible heat required to melt ice
b) is 335 kJ per 1 kg
c) is 335 kJ per 1 ton
d) is the latent heat required...
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