3e151 CDC Set C/P Volume 1
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Refrigerants containing chlorine are said to destroy
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Ozone
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Carbon
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Oxygen
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Nitrogen
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About This Quiz
The '3E151 CDC Set C\/P Volume 1' quiz assesses knowledge on refrigeration systems, focusing on components, heat types, and system processes. It tests understanding of practical HVAC applications, crucial for professionals in mechanical engineering and related fields.
Quiz Preview
- 2.
Which evaporator operating condition uses air circulation to aid in defrosting?
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Frosting
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Defrosting
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Nonfrosting
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Partial Frosting
Correct Answer
A. DefrostingExplanation
Defrosting is the evaporator operating condition that uses air circulation to aid in defrosting. During the defrosting process, the air circulation helps to melt the frost that has accumulated on the evaporator coils. This is typically achieved by temporarily reversing the direction of the refrigerant flow or by using electric heaters to warm the coils. The air circulation helps to distribute the warm air evenly across the coils, speeding up the defrosting process and ensuring efficient operation of the evaporator.Rate this question:
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- 3.
What must you do to the power before you perform a preoperational check on a heating, ventilation, air-conditioning, and refrigeration (HVAC/R) system?
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Turn off and confirm with a meter
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Lock the building if possible
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Properly tag the capacitors
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Remove the circuit breaker
Correct Answer
A. Turn off and confirm with a meterExplanation
To perform a preoperational check on an HVAC/R system, it is necessary to turn off the power and confirm it with a meter. This ensures that the system is completely shut down and there is no electrical current flowing through it, allowing for a safe inspection and maintenance. Using a meter helps to verify that the power is indeed off and prevents any accidental electrical shock or damage to the system during the check.Rate this question:
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- 4.
Which major component is considered to be the "heart" of the refrigeration system?
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Metering device
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Compressor
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Evaporator
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Condenser
Correct Answer
A. CompressorExplanation
The compressor is considered to be the "heart" of the refrigeration system because it is responsible for compressing the refrigerant gas, raising its pressure and temperature. This high-pressure gas is then sent to the condenser where it releases heat and becomes a high-pressure liquid. The compressor plays a crucial role in the refrigeration cycle by circulating the refrigerant and maintaining the flow of heat transfer throughout the system. Without the compressor, the refrigeration system would not be able to function properly.Rate this question:
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- 5.
Which refrigeration compressor is equipped with pistons and connecting rods?
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Screw
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Scroll
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Centrifugal
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Reciprocating
Correct Answer
A. ReciprocatingExplanation
A reciprocating refrigeration compressor is equipped with pistons and connecting rods. This type of compressor uses a piston-cylinder arrangement to compress the refrigerant by reciprocating motion. As the piston moves back and forth, it compresses the refrigerant gas, which is then discharged into the condenser. The reciprocating compressor is commonly used in small to medium-sized refrigeration and air conditioning systems due to its efficiency and reliability.Rate this question:
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- 6.
What term refers to how hot or cold a substance is?
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Temperature
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Pressure
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Enthalpy
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Entropy
Correct Answer
A. TemperatureExplanation
Temperature refers to how hot or cold a substance is. It is a measure of the average kinetic energy of the particles in a substance. When the particles have higher kinetic energy, the substance is hotter, and when they have lower kinetic energy, the substance is colder. Temperature is commonly measured using various scales such as Celsius, Fahrenheit, or Kelvin.Rate this question:
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- 7.
What is the term for a refrigeration unit to operate or cycle on?
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Cut-in
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Cut-out
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Differential
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Averaging temperature
Correct Answer
A. Cut-inExplanation
The term "cut-in" refers to the point at which a refrigeration unit starts operating or cycling on. It indicates the temperature at which the unit begins to cool down the environment. This term is commonly used in the context of thermostats or temperature control systems, where the cut-in temperature is set to activate the refrigeration unit and maintain the desired temperature range.Rate this question:
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- 8.
The best criteria to follow when you are inspecting equipment are
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Shop policies
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Your intuition
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Your supervisor's instructions
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The manufacturer's recomendations
Correct Answer
A. The manufacturer's recomendationsExplanation
When inspecting equipment, it is best to follow the manufacturer's recommendations. This is because the manufacturer knows their equipment best and can provide specific guidelines for inspection, maintenance, and safety. These recommendations are based on extensive testing and research, ensuring that the equipment functions optimally and remains in good condition. By adhering to the manufacturer's recommendations, you can minimize the risk of damage, malfunctions, and accidents, ultimately prolonging the lifespan of the equipment and ensuring its proper functioning.Rate this question:
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- 9.
All moving parts on an air compressor should have
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Pickets
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Guards
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V-belts installed
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Direct-drive motors
Correct Answer
A. GuardsExplanation
Guards should be installed on all moving parts of an air compressor to prevent accidents and injuries. Guards act as a protective barrier, preventing any contact between the moving parts and individuals nearby. They help to ensure the safety of the operators and anyone working in the vicinity of the air compressor. Without guards, there is a higher risk of accidents, such as entanglement or getting struck by the moving parts. Therefore, it is essential to have guards in place to maintain a safe working environment.Rate this question:
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- 10.
The float assembly in an oil separator is activated by the
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Level of the oil
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Low-side pressure
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Discharge pressure
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High-side pressure
Correct Answer
A. Level of the oilExplanation
The float assembly in an oil separator is activated by the level of the oil. This means that as the oil level rises, the float assembly is triggered and performs a specific action. This action could be signaling a control system to shut down the oil separator or activating a pump to remove excess oil. The float assembly serves as a crucial component in maintaining the proper oil level in the separator and preventing any potential issues that may arise from an overflow or insufficient oil level.Rate this question:
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- 11.
Which of these refrigerants has an ozone depletion rating of zero?
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R-12
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R-22
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R-134a
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R-500
Correct Answer
A. R-134aExplanation
R-134a is the correct answer because it has an ozone depletion rating of zero. This means that it does not contribute to the depletion of the ozone layer. R-12 and R-22, on the other hand, have ozone depletion potentials and can harm the ozone layer. R-500 was not mentioned in relation to its ozone depletion rating, so it cannot be determined if it has a rating of zero or not.Rate this question:
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- 12.
What must be balanced to distribute the load as equally as possible between multiple compressors?
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Oil separators
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Condensers
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Evaporators
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Refrigerant lines
Correct Answer
A. Refrigerant linesExplanation
To distribute the load as equally as possible between multiple compressors, the refrigerant lines must be balanced. The refrigerant lines are responsible for carrying the refrigerant from the compressors to the evaporators and condensers. By ensuring that the refrigerant lines are balanced, the flow of refrigerant can be evenly distributed among the compressors, preventing any one compressor from being overloaded. This helps to optimize the performance and efficiency of the system, ensuring that each compressor operates at its optimal capacity.Rate this question:
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- 13.
Two different metals that are bonded into a strip or coil are called
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Bimetal
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Joined metal
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Metal bonded
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Integrated metals
Correct Answer
A. BimetalExplanation
When two different metals are bonded together to form a strip or coil, it is known as a bimetal. The prefix "bi-" indicates that there are two metals involved in the bonding process. This term is commonly used in engineering and manufacturing industries to describe materials with different thermal expansion properties, allowing them to be used in applications such as thermostats, electrical switches, and temperature sensors.Rate this question:
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- 14.
To create the required pressure drop, the capillary tube uses a designed
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Reactance
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Resistance
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Flow increase
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Pressure increase
Correct Answer
A. ResistanceExplanation
The capillary tube creates the required pressure drop by using resistance. Resistance is the opposition to the flow of fluid through the tube, and by designing the capillary tube with a specific level of resistance, the desired pressure drop can be achieved. This resistance helps to regulate the flow rate and pressure of the fluid passing through the tube.Rate this question:
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- 15.
You are retrofitting a system that does not have a receiver. To do the job properly, you would store the refrigerant in
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A recovery cylinder
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The compressor
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The condenser
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The evaporator
Correct Answer
A. A recovery cylinderExplanation
To retrofit a system without a receiver properly, the refrigerant should be stored in a recovery cylinder. A recovery cylinder is designed to safely store and transport refrigerant during the retrofitting process. It allows for the proper handling and disposal of the refrigerant, ensuring that it does not escape into the atmosphere and cause environmental harm. Storing the refrigerant in the compressor, condenser, or evaporator would not be appropriate or effective for the retrofitting process.Rate this question:
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- 16.
The disadvantage of water-cooled condensers is
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Lower head pressure
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High heat transfer
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Compactness
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Higher cost
Correct Answer
A. Higher costExplanation
Water-cooled condensers have the disadvantage of higher cost compared to other types of condensers. This is because water-cooled condensers require additional equipment such as cooling towers, pumps, and water treatment systems, which can increase the overall cost of the system. Additionally, the installation and maintenance of water-cooled condensers can be more expensive compared to air-cooled condensers, further contributing to their higher cost.Rate this question:
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- 17.
Where do you install a sight glass and/or moisture indicator in a refrigeration system?
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Evaporator outlet
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Condenser inlet
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Suction line
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Liquid line
Correct Answer
A. Liquid lineExplanation
A sight glass and/or moisture indicator is installed in the liquid line of a refrigeration system. This is because the liquid line carries the condensed refrigerant from the condenser to the expansion device. By installing the sight glass and/or moisture indicator in this location, technicians can easily monitor the flow of refrigerant and detect any presence of moisture or contaminants. This helps ensure the proper functioning and efficiency of the refrigeration system.Rate this question:
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- 18.
What type of heat when added to a substance causes a measured temperature change without a change of state?
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Latent
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Specific
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Sensible
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Generic
Correct Answer
A. SensibleExplanation
Sensible heat refers to the type of heat that causes a measurable change in temperature without causing a change in the state of a substance. This means that when sensible heat is added to a substance, its temperature increases or decreases, but the substance remains in the same physical state (solid, liquid, or gas). Sensible heat transfer occurs due to the transfer of thermal energy between objects or substances with different temperatures, resulting in a measurable change in temperature.Rate this question:
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- 19.
The direct-expansion evaporator picks up or absorbs heat directly from the
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Outside air
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Conditioned space
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Primary refrigerant
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Secondary refrigerant
Correct Answer
A. Conditioned spaceExplanation
The direct-expansion evaporator picks up or absorbs heat directly from the conditioned space. This means that the evaporator is located within the conditioned space, such as inside an air conditioning unit or a refrigeration system. It is responsible for absorbing heat from the air or the space being cooled, and transferring it to the refrigerant. This allows the refrigerant to evaporate and carry the heat away, resulting in a cooling effect in the conditioned space.Rate this question:
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- 20.
What device is used to prevent liquid refrigerant from entering the compressor?
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Receiver
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Filter-drier
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Accumulator
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Oil separator
Correct Answer
A. AccumulatorExplanation
The device used to prevent liquid refrigerant from entering the compressor is called an accumulator. The accumulator is located in the suction line of the refrigeration system and its main function is to separate any liquid refrigerant from the refrigerant vapor before it enters the compressor. This is important because the compressor is designed to compress vapor and not liquid. The accumulator collects any liquid refrigerant and allows it to evaporate before it reaches the compressor, ensuring that only vapor is being compressed.Rate this question:
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- 21.
Which heat pump component prevents liquid refrigerant from entering the compressor?
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Drier
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Receiver
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Accumulator
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Oil separator
Correct Answer
A. AccumulatorExplanation
The accumulator is a heat pump component that prevents liquid refrigerant from entering the compressor. It is located between the evaporator and the compressor and its main function is to separate any remaining liquid refrigerant from the refrigerant vapor before it enters the compressor. This is important because if liquid refrigerant enters the compressor, it can cause damage to the compressor and affect the overall performance of the heat pump system. Therefore, the accumulator plays a crucial role in ensuring the proper functioning of the heat pump by preventing liquid refrigerant from entering the compressor.Rate this question:
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- 22.
The advantage of an air-cooled condenser is
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greater operating costs
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higher head pressures
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Fans that can become noisy
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Less maintenance
Correct Answer
A. Less maintenanceExplanation
An air-cooled condenser has the advantage of requiring less maintenance compared to other types of condensers. This is because it does not require water or other external cooling sources, making it easier to maintain and reducing the need for regular inspections and repairs. Additionally, there are no concerns about water leaks or water treatment, further reducing the maintenance requirements.Rate this question:
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- 23.
On systems that contain over how many pounds of refrigerant is passive recovery not authorized?
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7.5
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10
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12
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15
Correct Answer
A. 15Explanation
Passive recovery refers to the process of recovering refrigerant without the use of a recovery machine. It relies on the natural movement of refrigerant from a system to a recovery cylinder. According to the given answer, passive recovery is not authorized for systems that contain over 15 pounds of refrigerant. This means that for systems with more than 15 pounds of refrigerant, a recovery machine must be used to safely and efficiently recover the refrigerant.Rate this question:
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- 24.
Which pressure control has contacts that open on a rise in pressure?
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Low-pressure motor control
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Low-pressure safety control
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High-pressure safety switch
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High-pressure motor control
Correct Answer
A. High-pressure safety switchExplanation
A high-pressure safety switch is designed to open its contacts when the pressure rises above a certain threshold. This is a safety measure to prevent damage or malfunctioning of equipment or systems that operate under high pressure. By opening the contacts, the switch interrupts the circuit and stops the flow of current, thus preventing any further increase in pressure. This feature ensures the safety of the equipment and the surrounding environment by preventing overpressure situations.Rate this question:
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- 25.
How much of the refrigerant charge should a receiver hold?
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One-fourth
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One-half
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Three-fourths
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The entire amount
Correct Answer
A. The entire amountExplanation
The receiver in a refrigeration system is designed to hold the entire amount of refrigerant charge. This is because the receiver acts as a storage tank for the refrigerant, ensuring that there is always an adequate supply available for the system to operate efficiently. By holding the entire amount of refrigerant charge, the receiver helps to maintain proper refrigerant levels and prevent issues such as insufficient cooling or compressor damage.Rate this question:
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- 26.
What is a big problem with humidity control equipment?
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Shell
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Scale
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Glaze
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Crust
Correct Answer
A. ScaleExplanation
Scale is a big problem with humidity control equipment. Scale refers to the accumulation of mineral deposits, such as calcium and magnesium, on the surfaces of the equipment. These deposits can restrict the flow of air and water, reducing the efficiency and effectiveness of the equipment. Scale buildup can also lead to corrosion and damage to the equipment over time. Therefore, it is important to regularly clean and maintain humidity control equipment to prevent scale formation and ensure optimal performance.Rate this question:
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- 27.
On a centrifugal machine, the refrigerant flows from the first-stage impeller to the
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Purge unit
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Condenser
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Economizer
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Second-stage impeller
Correct Answer
A. Second-stage impellerExplanation
In a centrifugal machine, the refrigerant flows from the first-stage impeller to the second-stage impeller. This is because centrifugal machines typically have multiple stages, with each stage consisting of an impeller. The purpose of the impellers is to increase the pressure and velocity of the refrigerant. Therefore, after passing through the first-stage impeller, the refrigerant needs to flow to the second-stage impeller to undergo further compression and acceleration.Rate this question:
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- 28.
Which component is installed at the inlet of the evaporator?
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Metering device
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Accumulator
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Compressor
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Condenser
Correct Answer
A. Metering deviceExplanation
The metering device is installed at the inlet of the evaporator. This component is responsible for regulating the flow of refrigerant into the evaporator, ensuring that the correct amount of refrigerant enters the system. By controlling the flow, the metering device helps to maintain the desired temperature and pressure within the evaporator, allowing for efficient heat transfer and cooling.Rate this question:
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- 29.
What triggers a refrigeration unit to cycle on or off?
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Control circuit
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When plugged in
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When it is warm
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Load circuit
Correct Answer
A. Control circuitExplanation
The control circuit is responsible for triggering the refrigeration unit to cycle on or off. It regulates the operation of the unit based on temperature settings or other control inputs. When the control circuit detects that the desired temperature has been reached, it will turn off the unit. Conversely, when the temperature rises above the set point, the control circuit will activate the refrigeration unit to cool the environment. The control circuit plays a crucial role in maintaining the desired temperature and ensuring efficient operation of the refrigeration unit.Rate this question:
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- 30.
Which processes take place inside the condenser?
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Desuperheating and compression
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Desuperheating and condensing
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Vaporization and desuperheating
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Vaporization and condensing
Correct Answer
A. Desuperheating and condensingExplanation
Inside the condenser, two processes occur: desuperheating and condensing. Desuperheating refers to the process of reducing the temperature of superheated vapor, while condensing involves the transformation of vapor into a liquid state. These processes are essential for the functioning of the condenser, as they help to remove heat from the vapor and convert it back into a liquid form, allowing for the efficient operation of the overall system.Rate this question:
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- 31.
Heat that is picked up in the refrigeration system is rejected at the
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Condenser
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evaporator
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compressor
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metering device
Correct Answer
A. CondenserExplanation
In a refrigeration system, the condenser is responsible for the heat rejection process. After the refrigerant has absorbed heat from the evaporator, it enters the condenser where it releases the heat to the surrounding environment, typically through a set of coils or fins. This allows the refrigerant to cool down and return to a liquid state, ready to repeat the cooling cycle. Therefore, the correct answer is the condenser.Rate this question:
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- 32.
Which type of water-cooled condenser has removable heads that allow the tubes to be cleaned out with a revolving brush?
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Tube-within-a-tube
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Shell-and-tube
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Shell-and-coil
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Double-tube
Correct Answer
A. Shell-and-tubeExplanation
A shell-and-tube water-cooled condenser has removable heads that allow the tubes to be cleaned out with a revolving brush. In this type of condenser, the water flows through the tubes while the refrigerant flows around the tubes in a shell. The removable heads make it easier to access and clean the tubes, ensuring efficient heat transfer between the refrigerant and the water.Rate this question:
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- 33.
Temperature glide in an zeotropic refrigerant means that the refrigerant is a
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Blend that acts as one inside the refrigeration system
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Mixture that acts as one while inside the refrigeration system
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Blend that evaporates and condenses over a range of temperatures instead of a single temperature
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Mixture that liquefies and vaporizes over a range of temperatures instead of a single temperature
Correct Answer
A. Blend that evaporates and condenses over a range of temperatures instead of a single temperatureExplanation
The correct answer is "blend that evaporates and condenses over a range of temperatures instead of a single temperature." Temperature glide refers to the phenomenon where a zeotropic refrigerant undergoes both evaporation and condensation over a range of temperatures, rather than at a single temperature. This is due to the presence of different components with varying boiling and condensing points in the refrigerant blend.Rate this question:
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- 34.
What is the maximum fine and jail sentence that service technicians may be subject to for charging a system with an unacceptable refrigerant?
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$10,000 and 5 years
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$10,000 and 10 years
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$25,000 and 5 years
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$25,000 and 10 years
Correct Answer
A. $25,000 and 5 yearsExplanation
Service technicians may be subject to a maximum fine of $25,000 and a jail sentence of 5 years for charging a system with an unacceptable refrigerant.Rate this question:
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- 35.
Which packaged unit normally uses only one fan motor?
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Heat pump
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Window unit
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Floor-mounted
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Central self-contained
Correct Answer
A. Window unitExplanation
A window unit is a type of packaged unit that typically uses only one fan motor. Unlike other types of packaged units such as heat pumps, floor-mounted units, and central self-contained units, a window unit is designed to be installed in a window and is compact enough to cool or heat a single room. The use of only one fan motor in a window unit helps to keep the unit small and portable, making it a convenient option for cooling or heating small spaces.Rate this question:
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- 36.
What is the line to inlet relationship of refrigerant vapor travel as it leaves the evaporator?
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Suction to condenser
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Suction to compressor
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Discharge to condenser
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Discharge to compressor
Correct Answer
A. Suction to compressorExplanation
The correct answer is "Suction to compressor." In a refrigeration system, the suction line connects the evaporator outlet to the compressor inlet. This line carries the low-pressure refrigerant vapor from the evaporator to the compressor, where it is compressed and sent to the condenser for further cooling. Therefore, the suction line is responsible for transporting the refrigerant vapor from the evaporator to the compressor.Rate this question:
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- 37.
Complete vaporization in an evaporator occurs at point
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C
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G
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S
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V
Correct Answer
A. VExplanation
The correct answer is V because complete vaporization in an evaporator occurs at the vapor outlet point, where all the liquid has been evaporated and only vapor is present.Rate this question:
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- 38.
In a multi stage air-compressor installation, what is used to remove heat between the stages?
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Aftercoolers
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Intercoolers
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Accumulators
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Receivers
Correct Answer
A. IntercoolersExplanation
Intercoolers are used to remove heat between the stages in a multi-stage air-compressor installation. These devices cool down the compressed air between each stage, preventing excessive heat buildup and reducing the overall temperature of the air. This cooling process improves the efficiency and performance of the compressor, as it allows for denser air to be compressed in the subsequent stages. Intercoolers are essential in maintaining the optimal operating conditions and preventing damage to the compressor.Rate this question:
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- 39.
Which alternative replacement for R–502 is a patented azeotrope?
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R-507
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R-409A
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R-404A
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R-402A
Correct Answer
A. R-507Explanation
R-507 is a patented azeotrope alternative replacement for R-502. This means that R-507 is a mixture of two or more refrigerants that behave as a single substance, providing similar cooling properties as R-502. It is protected by a patent, indicating that it is a proprietary blend and cannot be replicated or used without permission. Therefore, R-507 is the correct answer as it meets the criteria of being a patented azeotrope replacement for R-502.Rate this question:
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- 40.
How does the rotary compressor compress the refrigerant vapor?
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Rotating action
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Squeezing action
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Increasing the volume
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Decreasing the pressure
Correct Answer
A. Squeezing actionExplanation
The rotary compressor compresses the refrigerant vapor through a squeezing action. This means that the compressor uses rotating action to squeeze the vapor, reducing its volume and increasing its pressure. As the vapor is squeezed, its molecules are forced closer together, resulting in a higher pressure. This process is essential for the efficient operation of the refrigeration system, as it allows the vapor to be condensed and cooled before being circulated again.Rate this question:
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- 41.
During retrofitting, which component might have to be reset to compensate for higher discharge pressures?
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Oil-pressure cutout
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Low-pressure cutout
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High-pressure cutout
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Crankcase-pressure cutout
Correct Answer
A. High-pressure cutoutExplanation
During retrofitting, when higher discharge pressures are encountered, the high-pressure cutout might have to be reset. This is because the high-pressure cutout is designed to protect the system from excessive pressure, and if the discharge pressures are higher than normal after retrofitting, the cutout may need to be adjusted to prevent damage to the system.Rate this question:
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- 42.
Where are the coldest rooms located in a permanent cold-storage plant?
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Inside
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Outside
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At one end
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At one side
Correct Answer
A. InsideExplanation
The coldest rooms in a permanent cold-storage plant are located inside the facility. This is because the purpose of a cold-storage plant is to maintain a low temperature for preserving perishable items. Therefore, the coldest rooms are situated inside the plant to ensure that the desired temperature is maintained and that the stored items remain fresh and unspoiled.Rate this question:
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- 43.
What program is designed to keep heating, ventilation, air-conditioning, and refrigeration (HVAC/R) equipment in operational condition?
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Operational check program
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Preoperational check program
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Recurring maintenance program
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Real property installed equipment program
Correct Answer
A. Recurring maintenance programExplanation
A recurring maintenance program is designed to keep heating, ventilation, air-conditioning, and refrigeration (HVAC/R) equipment in operational condition. This program involves regularly scheduled inspections, cleaning, and repairs to ensure that the equipment is functioning properly and efficiently. By implementing a recurring maintenance program, potential issues can be identified and addressed before they become major problems, helping to extend the lifespan of the equipment and minimize downtime.Rate this question:
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- 44.
Cleaning a refrigerant at the job site or at a local service shop is called
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Recycling
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Reclamation
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Redeeming
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Recovery
Correct Answer
A. RecyclingExplanation
The process of cleaning a refrigerant at the job site or at a local service shop is referred to as recycling. This involves removing any impurities or contaminants from the refrigerant to make it suitable for reuse. Recycling helps to minimize waste and conserve resources by extending the lifespan of the refrigerant, reducing the need for new refrigerant production.Rate this question:
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- 45.
When polyolester oil is used in place of mineral oil during a retrofit procedure, you must make sure that less than what percent of mineral oil can remain in the system?
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5
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4
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3
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2
Correct Answer
A. 5Explanation
During a retrofit procedure, when polyolester oil is used instead of mineral oil, it is crucial to ensure that less than 5% of mineral oil remains in the system. This is because the two types of oils have different properties and mixing them can lead to issues such as reduced lubrication efficiency and potential damage to the system components. Therefore, it is important to thoroughly flush the system and remove as much mineral oil as possible before using polyolester oil.Rate this question:
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- 46.
An ice-cream cabinet is similar to a
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Chest-type freezer
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Single-door refrigerator
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Side-by-side refrigerator
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Bottom-freezer combination
Correct Answer
A. Chest-type freezerExplanation
An ice-cream cabinet is similar to a chest-type freezer because both have a similar design and function. A chest-type freezer typically has a hinged lid on top and a large storage space inside, allowing for easy access and efficient freezing of food items. Similarly, an ice-cream cabinet also has a similar design with a lid on top and is specifically designed to store and display ice cream products. Both the chest-type freezer and ice-cream cabinet provide a low temperature environment to keep the items inside frozen and preserved for a longer period of time.Rate this question:
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- 47.
Which organization requires that a comprehensive risk assessment be performed to estimate the likelihood of fire and potential results should a fire occur when alternative refrigerants contain a flammable component?
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Air-Conditioning and Refrigerant Institute (ARI)
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Environmental Protection Agency (EPA)
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American Society of Testing Materials (ASTM)
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American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)
Correct Answer
A. Environmental Protection Agency (EPA)Explanation
The Environmental Protection Agency (EPA) requires a comprehensive risk assessment to be performed in order to estimate the likelihood of fire and potential results if a fire were to occur when alternative refrigerants contain a flammable component. This is because the EPA is responsible for regulating and enforcing environmental laws and regulations, including those related to the use and handling of hazardous substances such as refrigerants. By requiring a risk assessment, the EPA aims to ensure that proper safety measures are in place to prevent and mitigate the risks associated with flammable refrigerants.Rate this question:
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- 48.
The thermostatic expansion valve maintains a fully active evaporator by
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Reducing heat load
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Enhancing condensation
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Maintaining the proper amount of superheat
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Maintaining the proper amount of subcooling
Correct Answer
A. Maintaining the proper amount of superheatExplanation
The thermostatic expansion valve is responsible for regulating the flow of refrigerant into the evaporator coil. It does this by sensing the temperature of the refrigerant leaving the evaporator and adjusting the size of the valve opening accordingly. By maintaining the proper amount of superheat, which is the temperature difference between the refrigerant vapor and its saturation temperature, the expansion valve ensures that the evaporator is operating efficiently. This helps to prevent the formation of liquid refrigerant in the evaporator, which can cause a loss of cooling capacity and potential damage to the compressor.Rate this question:
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- 49.
How is the capillary tube in a system affected by the refrigerant charge?
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The refrigerant charge is critical
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The refrigerant pressure can fluctuate
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The system can take extra refrigerant
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The system can take a less amount of refrigerant
Correct Answer
A. The refrigerant charge is criticalExplanation
The refrigerant charge refers to the amount of refrigerant present in the system. If the charge is not at the correct level, it can have a significant impact on the performance of the system, including the capillary tube. The capillary tube is responsible for regulating the flow of refrigerant through the system. If the refrigerant charge is too high or too low, it can cause the capillary tube to become ineffective in controlling the flow, leading to issues such as improper cooling or inefficient operation. Therefore, it is crucial to ensure that the refrigerant charge is at the correct level for optimal system performance.Rate this question:
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Mar 20, 2023Quiz Edited by
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Jan 25, 2017Quiz Created by
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