Refrigerant Machine Operator License Exam Prep Test

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1. COPPER USED IN REFRIGERATION SYSTEMS, LIKE IN HEAT EXCHANGERS, BECAUSE?

Explanation

Copper is used in refrigeration systems, like in heat exchangers, because of its high thermal conductivity. Thermal conductivity refers to the ability of a material to conduct heat. Copper has one of the highest thermal conductivities among metals, allowing it to efficiently transfer heat. This is important in refrigeration systems as it helps in the rapid cooling and heat exchange process, ensuring efficient functioning of the system. Additionally, copper is also easy to fabricate and has good durability, but its high thermal conductivity is the main reason for its use in refrigeration systems.

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About This Quiz
Refrigerant Machine Operator License Exam Prep Test - Quiz

Below is a quiz on the refrigerant machine operator! It is designed to help an operator review all that they know about fridges and how to correct any... see moredefaults they may be experiencing. How about you give it a shot and get to see if all you know is enough to provide you with the certification. All the best of luck! see less

2. OF THE FOLLOWING THE MOST CORRECT WAY TO DESCRIBE A BRAZED JOINT IS

Explanation

A brazed joint is a type of joint that is created by joining two pieces of metal using a filler metal that has a lower melting point than the base metals. The filler metal is heated and melted, and then it flows into the joint, creating a strong and durable bond. The most correct way to describe a brazed joint is as a gas tight fitting because the process of brazing creates a joint that is sealed and leak-proof, making it suitable for applications where a tight seal is required.

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3. R-22 IS:

Explanation

The given correct answer is "ODORLESS". This means that R-22 does not have a distinct smell.

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4. IN A COMPRESSOR'S ELECTRICAL BOX ONE OF THE HOT WIRES IS TOUCHING THE METAL BOX, WHAT WOULD MOST LIKELY HAPPEN?

Explanation

If one of the hot wires in a compressor's electrical box is touching the metal box, it can create an electrical fault. This can cause the metal box to become electrified, posing a risk of electric shock to anyone who touches it, including RMO workers. Therefore, the correct answer is that RMO workers can receive an electric shock if they touch it.

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5. A MOTOR HAS 4 BELTS, THE CENTER BELT IS WORN, YOU WOULD

Explanation

The correct answer is to change the center belt and all other belts. This is because if the center belt is worn, it is likely that the other belts are also worn and may need to be replaced. Changing all the belts ensures that the motor will function properly and reduces the risk of any further belt-related issues.

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6. OF THE FOLLOWING CHARACTERISTICS OF REFRIGERANT, THE ONE THAT BEST DESCRIBES REFRIGERANT 22 IS:

Explanation

Refrigerant 22 is described as odorless when mixed with air. This means that it does not have a distinct smell when it is in the air.

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7. AS AN RMO IN CHARGE, YOU ARE REQUESTED TO REPLACE THE GAUGE ON THE HIGH SIDE OF THE REFRIGERATION SYSTEM.  THE PRESSURE GRADUATION RATE SHOULD BE

Explanation

The correct answer is 1.2 OF DESIGN PRESSURE (AT LEAST). This means that the pressure graduation rate of the new gauge should be at least 1.2 times the design pressure of the refrigeration system. This ensures that the gauge can accurately measure the pressure within the system and can handle the maximum pressure that the system is designed for. By replacing the gauge with one that meets this requirement, the RMO in charge can ensure the safe and efficient operation of the refrigeration system.

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8. YOU ARE AN RMO ASSIGNED TO FACILITY WHERE A REFRIGERANT HAS BEEN RECENTLY CHANGED FROM A FLAMMABLE REFRIGERANT TO R-22, AT THE MOMENT YOU ARE PLANNING TO BRAZE METAL.  ON SUCH MAKING A REPAIR IN THE MACHINERY ROOM, UNDER THESE CIRCUMSTANCES YOU:

Explanation

When working in a facility where the refrigerant has been changed to R-22, it is important to ensure safety when brazing metal. The correct answer states that the flame must be enclosed and vented to open air. This means that any flame used during the repair process should be contained within a safe enclosure and any fumes or gases produced should be vented to the open air. This is crucial to prevent any potential ignition or release of flammable gases that may be present due to the change in refrigerant. It prioritizes safety and minimizes the risk of accidents or hazards.

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9. WHEN INSTALLING A SERVICE VALVE TO ISOLATE A DUAL PRESSURE DEVICE WHILE KEEPING SYSTEM IN SERVICE, YOU WOULD USE A 

Explanation

When installing a service valve to isolate a dual pressure device while keeping the system in service, a three-way valve would be used. A three-way valve has three ports, allowing for the diversion of flow between two different paths. In this case, the three-way valve would be able to redirect the flow from the dual pressure device to either the system or to a bypass line, effectively isolating the device without interrupting the system's operation.

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10. WHY IS SPRING LOADED PRV BETTER TO USE THAN A FUSIBLE PLUG?

Explanation

The reason why a spring-loaded PRV (Pressure Relief Valve) is better to use than a fusible plug is that the fusible plug cannot reset. Once the fusible plug melts and releases pressure, it cannot be reused or reset. On the other hand, a spring-loaded PRV can be reset after it has relieved pressure, making it more convenient and cost-effective in the long run. Additionally, spring-loaded PRVs are generally easier to find and readily available compared to fusible plugs.

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11. WHEN INSTALLING A PIPELINE AND YOU NEED TO MAKE A 90° ELBOW, WHICH IS THE BEST WAY?

Explanation

Using a factory-made 90° elbow and brazing is the best way to make a 90° elbow when installing a pipeline. This method ensures a secure and reliable connection between the pipes, as the factory-made elbow is designed specifically for this purpose. Brazing helps to create a strong joint between the elbow and the pipes, ensuring that it can withstand the pressure and flow of the fluid or gas passing through the pipeline. Using a factory-made elbow also saves time and effort compared to bending the pipe or using multiple 45° elbows.

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12. SEMI-HERMETIC COMPRESSORS MAY BE BETTER TO USE THAN HERMETIC COMPRESSORS BECAUSE HERMETIC COMPRESSORS:

Explanation

Semi-hermetic compressors may be better to use than hermetic compressors because hermetic compressors are fully enclosed and cannot be serviced on site. This means that if there is any issue or maintenance required, the entire compressor unit needs to be replaced, which can be time-consuming and costly. In contrast, semi-hermetic compressors can be serviced on site, allowing for easier maintenance and potentially reducing downtime and costs.

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13. WHAT SAFETY GROUP DOES AMMONIA BELONG?

Explanation

Ammonia belongs to Safety Group 2, B2. This classification indicates that ammonia is a hazardous substance, but with proper handling and precautions, it can be safely used. The B2 designation suggests that ammonia is a flammable gas, which means it can ignite and burn in certain conditions. It is important to follow safety protocols and guidelines when working with ammonia to prevent accidents and ensure the well-being of individuals and the environment.

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14. WHEN CHANGING WATER TO ICE, WHAT MUST BE REMOVED?

Explanation

When changing water to ice, latent heat must be removed. Latent heat is the heat energy required to change the state of a substance without changing its temperature. In the case of water, when it is cooled below its freezing point, the latent heat must be removed in order for it to solidify and become ice. This heat energy is used to break the intermolecular bonds between water molecules, allowing them to arrange themselves in a solid crystalline structure.

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15. ACCORDING TO NYC FIRE CODE CLASSIFICATION OF REFRIGERANT, AMMONIA WOULD FALL UNDER WHICH GROUP?

Explanation

Ammonia would fall under Group 2 according to the NYC Fire Code classification of refrigerant. This means that it is classified as a moderately hazardous material.

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16. OF THE FOLLOWING, WHICH REFRIGERANT REQUIRES THE APPROVAL FOR USE BY THE NYC FIRE DEPT?

Explanation

Butane is the correct answer because it is a flammable refrigerant that requires approval for use by the NYC Fire Department. R-22 and R-12 are both commonly used refrigerants but do not require special approval. Carbon dioxide is a non-flammable refrigerant and also does not require approval.

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17. ACCORDING TO THE SAFETY HAND BOOK, HOW MUCH REFRIGERANT CAN BE RECOVERED INTO A 60 LB CONTAINER?

Explanation

According to the safety handbook, a 60 lb container can recover up to 45 lbs of refrigerant.

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18. BECAUSE OF THE LATENT HEAT LOAD, REFRIGERATION MACHINE OPERATOR WAS INSTRUCTED TO START THE RECIPROCATING PLANT FOR AIR CONDITIONING.  OF THE FOLLOWING ACCORDING TO RECOMMENDED PRACTICE, THE FIRST THING TO DO IS

Explanation

The correct answer is to turn on the chilled water pump, condenser water pumps, and cooling tower fans. This is because the latent heat load requires the refrigeration machine operator to start the reciprocating plant for air conditioning. To effectively handle this load, it is necessary to ensure the proper circulation of chilled water, condenser water, and cooling tower air. Therefore, turning on the chilled water pump, condenser water pumps, and cooling tower fans is the recommended practice to address the latent heat load.

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19. WHAT REFRIGERANT SYSTEMS ARE MOST LIKELY TO LEAK REFRIGERANT IN BUILDING SPACES THAT ARE BEING COOLED?

Explanation

Direct systems are most likely to leak refrigerant in building spaces that are being cooled. This is because direct systems have direct contact between the refrigerant and the building space being cooled, which increases the chances of leaks occurring. In contrast, indirect systems have a separate closed loop for the refrigerant, reducing the likelihood of leaks.

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20. WHEN CHARGING AN R-12 RECIPROCATING REFRIGERATION SYSTEM, AN OPERATOR WOULD WANT TO USE WARM WATER TO INCREASE THE RELEASE RATE OF REFRIGERANT FROM THE DRUM.  TO PERFORM THIS OPERATION THE WATER TEMP. SHOULD NOT EXCEED THE DEGREE °F OF

Explanation

When charging an R-12 reciprocating refrigeration system, using warm water can increase the release rate of refrigerant from the drum. However, the water temperature should not exceed 90°F. If the water temperature is too high, it can cause the refrigerant to vaporize too quickly, leading to unstable charging and potential damage to the system. Therefore, it is important to use warm water within the specified temperature range to ensure safe and effective charging of the system.

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21. IN A REFRIGERATION PLANT, A SMALL INDUCTION REFRIGERATION MOTOR IS RUNNING ON AC CURRENT.  IN ORDER FOR THE OPERATOR TO DETERMINE THE TRUE POWER CONSUMPTION, ASSUMING THAT IF EVERY ELIGIBLE CHARACTERISTICS HAVE BEEN MEANT, OF THE FOLLOWING THE POWER CONSUMPTION IS DETERMINED BY THE APPLICATION OF THE FORMULA:

Explanation

The correct answer is WATTS = VOLTS X AMPS X POWER FACTOR. This formula is used to determine the true power consumption in a refrigeration plant when a small induction refrigeration motor is running on AC current. The power consumption is calculated by multiplying the voltage, current, and power factor. The power factor takes into account the phase difference between the voltage and current waveforms and represents the efficiency of the motor in converting electrical power into useful work. Therefore, including the power factor in the formula provides a more accurate measurement of the true power consumption.

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22. IN AN EMERGENCY IF YOU MUST DUMP REFRIGERANT INTO SEWER, YOU WILL DUMP ONLY WHEN

Explanation

The correct answer is "YOU DISCHARGE UNDER THE SUPERVISION OF THE FIRE DEPT." because in an emergency situation where refrigerant needs to be dumped into the sewer, it is important to ensure that proper safety measures are followed. Discharging under the supervision of the fire department ensures that the process is carried out in a controlled manner, minimizing the risk of harm to the environment and individuals. The fire department can provide guidance and oversight to ensure that the disposal is done safely and in compliance with regulations.

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23. WHAT IS PURPOSE OF HAVING A SERVICE VALVE STEM CAP?

Explanation

The purpose of having a service valve stem cap is to protect the valve from being inadvertently turned from its position and from being damaged. The cap acts as a protective cover that prevents any accidental movement or tampering of the valve, ensuring that it remains in its intended position. Additionally, the cap also provides a layer of protection against external elements that could potentially cause damage to the valve, such as dirt, debris, or moisture.

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24. WHICH OF THE FOLLOWING ASHRAE SAFETY GROUPS IS THE MOST DANGEROUS?

Explanation

The correct answer is B3. This implies that among the given options, the ASHRAE Safety Group B3 is the most dangerous. However, without further information, it is not possible to provide a specific explanation as to why B3 is considered the most dangerous.

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25. Is [your statement here] true or false?

Explanation

The given correct answer is true.

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26. AN AUTOMATIC PURGE UNIT IS REQUIRED FOR THOSE REFRIGERATING SYSTEMS THAT HAVE

Explanation

An automatic purge unit is required for refrigerating systems operating below atmospheric pressure. This is because when a system operates below atmospheric pressure, there is a higher likelihood of air and moisture entering the system. The automatic purge unit helps to remove any air and moisture that may have entered the system, ensuring the system operates efficiently and effectively.

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27. A RMO WOULD EXPECT A RELIEF VALVE TO START FUNCTIONING (FOR THE SECTION OF REFRIGERATING SYSTEM BEING PROTECTED) AT A PRESSURE MOST CLOSEST TO:

Explanation

A relief valve is designed to protect a refrigerating system from excessive pressure. It is set to open and release the excess pressure when it reaches a certain threshold. The design pressure is the maximum pressure that the system is designed to safely handle. Therefore, a RMO (Refrigeration Maintenance Operator) would expect the relief valve to start functioning at the design pressure, as this is the point where the system is at risk of being damaged or compromised.

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28. R-11 AND R-123 REFRIGERANTS ARE

Explanation

The correct answer is "ALL OF THE ABOVE". R-11 and R-123 refrigerants are known to be oxygen depleting, meaning they can reduce the amount of oxygen available in an area. They are also heavier than air, which means they tend to sink and accumulate in low-lying areas. Additionally, R-11 and R-123 are classified as Class-1 and Class-2 substances by the Environmental Protection Agency (EPA), indicating that they are considered to be potentially harmful to human health and the environment.

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29. AN RMO NOTICES A KNOCKING RECIPROCATING COMPRESSOR.  THE RMO IS ASSURED THE COMPRESSOR HAS NO WORN PARTS.  THE MOST PROBABLE CAUSE OF THE KNOCKING IS:

Explanation

The most probable cause of the knocking in the reciprocating compressor is liquid slugging. Liquid slugging occurs when liquid refrigerant enters the compressor, causing damage to the internal components and resulting in knocking or banging noises. This can happen due to factors such as improper refrigerant charge, liquid refrigerant entering the suction line, or a malfunctioning expansion valve. It is important to address this issue promptly to prevent further damage to the compressor.

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30. THE ADVANTAGE OF FORCED DRAFT OVER NATURAL DRAFT COOLING TOWER IS:

Explanation

Forced draft cooling towers have the advantage of lower water outlet temperature compared to natural draft cooling towers. This is because forced draft towers use fans to force air through the tower, resulting in better heat transfer and lower water temperatures. Additionally, forced draft towers are not dependent on natural wind velocity, allowing for more consistent cooling performance. Lastly, the use of fans in forced draft towers allows for a smaller tower size, making them more space-efficient. Therefore, all of the above statements are advantages of forced draft over natural draft cooling towers.

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31. AN OPERATOR HAS BEEN ASSIGNED TO RUN  A RECIPROCATING COMPRESSOR.  THE FOLLOWING ACTION CAPACITY CONTROL WOULD MOST LIKELY BE ACHIEVED THROUGH:

Explanation

The action of capacity control in a reciprocating compressor is most likely achieved by opening the suction valves with some form of control. By adjusting the opening of the suction valves, the amount of gas entering the compressor can be controlled, thus regulating the capacity of the compressor. This allows for flexibility in matching the compressor's output to the required demand, ensuring efficient operation.

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32. GIVEN A REFRIGERATION SYSTEM WHICH INCLUDES A FORCED DRAFT COOLING TOWER, AN ECONOMIZER AND CHILLED WATER AS THE COOLING MEDIUM, THE HEAT THAT IS REMOVED FROM THE BUILDING IS FINALLY REJECTED:

Explanation

The correct answer is "AS HEAT OF EVAPORATION OF THE COOLING TOWER". In a refrigeration system with a forced draft cooling tower, the cooling tower removes heat from the building by evaporating water. As the water evaporates, it absorbs heat from the building, effectively cooling it down. This heat is then rejected into the atmosphere, making the heat of evaporation of the cooling tower the final destination for the heat removed from the building.

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33. WHAT IS THE TEV DIAPHRAM MADE OF

Explanation

The explanation for the correct answer, METAL, is that the TEV diaphragm is typically made of a flexible metal material. This is because a metal diaphragm provides better durability and resistance to high pressures and temperatures compared to other materials like rubber, plastic, or graphite. The metal diaphragm also ensures a more accurate and reliable operation of the TEV, which is essential for regulating the flow of refrigerant in cooling systems.

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34. IF YOU JUST PURCHASED A THERMOMETER AND NEED TO CHECK TO SEE IF ITS WORKING PROPERLY, HOW WOULD YOU DO IT?

Explanation

To check if a newly purchased thermometer is working properly, you can touch it to a bucket of ice or ice water. This is because the melting point of ice is known to be 0 degrees Celsius or 32 degrees Fahrenheit. By placing the thermometer in the ice water, you can verify if it accurately reads this temperature. If the thermometer displays a different reading, it may indicate a malfunction or calibration issue. Comparing it to other thermometers or an RMO thermometer can also be helpful in determining its accuracy.

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35. AN OPERATOR HAS BEEN ASSIGNED TO RUN A CENTRIFUGAL COMPRESSOR.  OF THE FOLLOWING ACTIONS A CAPACITY CONTROL IS MOST LIKELY TO ACHIEVE IS THROUGH

Explanation

Adjustment of the impeller inlet guide pre-rotation vanes is most likely to achieve capacity control in a centrifugal compressor. By adjusting the vanes, the flow of gas into the impeller can be controlled, thereby affecting the compressor's capacity. This allows the operator to regulate the amount of gas being compressed, ensuring that the compressor operates at the desired capacity. Bypass discharge gas, condenser pressure variation, and adding re-expansion volume may have other functions in a centrifugal compressor system, but they are not specifically related to capacity control.

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36. WITH RESPECT TO FIRE SAFETY, THE ANSI/ASHRAE REFRIGERANT SAFETY CLASSIFICATION THAT IS MOST DANGEROUS IS

Explanation

The correct answer is A3. In terms of fire safety, the ANSI/ASHRAE refrigerant safety classification that is most dangerous is A3. Refrigerants classified as A3 are highly flammable and can pose a significant fire hazard if not handled properly. It is important to take appropriate precautions and follow safety guidelines when working with A3 refrigerants to minimize the risk of fire accidents.

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37. A PUMP AFFECTS THE PRESSURE OF A FLUID OR GAS BY: 

Explanation

A pump affects the pressure of a fluid or gas by raising the pressure. When a pump is used, it applies force to the fluid or gas, increasing its pressure. This is typically done by increasing the velocity of the fluid or gas and then converting that velocity into pressure. As a result, the pressure of the fluid or gas is raised, allowing it to flow or be used in various applications.

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38. A RMO NEEDED TO VARY THE FLOW OF REFRIGERANT IN A SYSTEM.  A CONTINUOUS VARIATION IN THE FLOW OF THE SYSTEM DOES NOT INCLUDE THE:

Explanation

The solenoid valve is not capable of providing a continuous variation in the flow of refrigerant in a system. It can only be either fully open or fully closed, resulting in a binary on/off flow. Therefore, it is not included in the options for a continuous variation in flow.

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39. WHEN PROPERLY PURGING YOU SHOULD

Explanation

When properly purging, you should stop when the pressure ceases to drop. This means that all the unwanted gases or contaminants have been successfully removed from the system. Continuing to purge beyond this point would be unnecessary and a waste of time and resources.

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40. WHICH IS NOT USED AS A COOLING MEDIUM IN AN INDIRECT SYSTEM

Explanation

R-22 is not used as a cooling medium in an indirect system. R-22 is a hydrochlorofluorocarbon (HCFC) refrigerant that was commonly used in air conditioning and refrigeration systems. However, due to its harmful effects on the ozone layer, its production and use have been phased out in many countries. In indirect cooling systems, other cooling mediums such as calcium chloride, glycol, or sodium chloride are used instead.

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41. MACHINE ROOM SAFETY STANDARDS HAVE BEEN ESTABLISHED BY

Explanation

ASHRAE 15 is the correct answer because it is a standard developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) specifically for safety requirements in refrigeration systems. It provides guidelines and regulations for the design, construction, installation, and operation of refrigeration systems to ensure the safety of personnel working in machine rooms. ARI-700 and ARI-740 are not related to machine room safety, and while ASHRAE 34 is a standard for refrigerant classification, it does not specifically address machine room safety.

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42. ONE DISADVANTAGE IN USING BRINES AS A COOLING MEDIUM IS CORROSION.  IN COMMERCIAL PRACTICE CORROSION AND THE AMOUNT OF RUST FORMED IS REDUCED BY THE ADDITION TO THE BRINE SOLUTION OF:

Explanation

The use of di-chromates in brine solutions helps to reduce corrosion and the formation of rust. Di-chromates have anti-corrosive properties and can form a protective layer on metal surfaces, preventing them from coming into contact with the brine solution and reducing the likelihood of corrosion. This makes di-chromates an effective additive for maintaining the integrity and longevity of cooling systems that use brines as a cooling medium.

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43. WHICH TYPE OF PUMP IS CONSIDERED A NON-POSITIVE DISPLACEMENT PUMP?

Explanation

A centrifugal pump is considered a non-positive displacement pump because it uses centrifugal force to move fluid rather than trapping and displacing a fixed amount of fluid with each rotation, like positive displacement pumps do. Instead, a centrifugal pump uses an impeller to spin the fluid, creating a centrifugal force that pushes the fluid outward. This design allows for a continuous flow of fluid, making it more suitable for applications where a constant flow rate is required.

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44. HOW MANY BTUs WOULD BE REMOVED IN A 30 TON SYSTEM?

Explanation

In a 30 ton system, the correct answer is 360,000 BTUs per hour. This means that the system has the capacity to remove 360,000 BTUs of heat energy from the space it is cooling every hour. The other options, such as 12,000 BTUs per hour or 360,000 BTUs per minute, are not correct as they do not accurately represent the capacity of a 30 ton system.

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45. DUE TO A COLD FRONT, THERE WAS A SHARP DROP IN O.A.T., THE MOST LIKELY EFFECT OF THIS CONDITION ON THE OPERATION OF THE RECIPROCATING MACHINE WOULD BE THAT THE THERMOSTAT CAUSES SOLENOID VALVE TO:

Explanation

The cold front caused a sharp drop in outside air temperature (O.A.T.), which would activate the thermostat. In response, the thermostat would cause the solenoid valve to close. As a result, the compressor would pump down and shut down due to low pressure. This is the most likely effect because when the solenoid valve closes, it restricts the flow of refrigerant, causing the compressor to pump down and reach low pressure, leading to a shutdown.

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46. OF THE FOLLOWING THE MOST COMMON METERING DEVICE USED TODAY IN A RECIPROCATING COMMERCIAL REFRIGERATION SYSTEM OVER 3 TONS IS

Explanation

The most common metering device used today in a reciprocating commercial refrigeration system over 3 tons is the thermostatic expansion valve. This valve is designed to control the flow of refrigerant into the evaporator based on the temperature and pressure conditions. It ensures that the right amount of refrigerant is supplied to the evaporator to maintain optimum cooling efficiency. The thermostatic expansion valve is preferred over other options like automatic expansion valve, low side float, and high side float due to its ability to provide precise control and better performance in a wide range of operating conditions.

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47. THE AMOUNT OF REFRIGERANT THAT FLOWS THROUGH THE ORIFICE PLATE IS DETERMINED BY:

Explanation

The amount of refrigerant that flows through the orifice plate is determined by the difference in pressure between the high and low sides. This is because the pressure difference creates a pressure drop across the orifice plate, which in turn controls the flow rate of the refrigerant. The higher the pressure difference, the greater the flow rate of the refrigerant through the orifice plate. Conversely, a lower pressure difference will result in a lower flow rate of refrigerant. The number of economizer stages, the number of compression stages, and the temperature of the refrigerant in the high side do not directly affect the flow rate of the refrigerant through the orifice plate.

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48. IF AN ELECTRIC MOTOR IS REWOUND TO CUT RESISTANCE BY 1/2, ALL OTHER FACTORS BEING EQUAL, THE MOTOR POWER WOULD:

Explanation

When an electric motor is rewound to cut resistance by 1/2, it means that the resistance in the motor circuit has been reduced. Since power is directly proportional to the square of the current and inversely proportional to the resistance, reducing the resistance by 1/2 will result in a doubling of the current. As a result, the power of the motor will increase by a factor of 2.

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49. ORIFICE PLATES MAY BE USED AS A METERING DEVICE COMPONENT IN A CENTRIFUGAL SYSTEM.  THE VESSEL WHICH THEY ARE CONTAINED IN CAN ALSO SERVE AS

Explanation

Orifice plates can be used as a metering device component in a centrifugal system. The vessel in which they are contained can also serve as an economizer. An economizer is a device that preheats the feedwater by utilizing the waste heat from the flue gases before they are discharged to the atmosphere. This helps in improving the overall efficiency of the system by reducing the energy required for heating the feedwater. Therefore, in this context, the vessel containing the orifice plates can also function as an economizer.

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50. A RMO WAS INSTRUCTED TO CHARGE A 60 TON PLANT WITH R-134A REFRIGERANT.  THE OPERATOR WOULD MOST LIKELY FIND THE CHARGING VALVE ON THE:

Explanation

The charging valve for the R-134A refrigerant is most likely to be found on the low pressure side of the equipment. This is because the low pressure side is where the refrigerant enters the system and is typically where charging is done. Charging the refrigerant on the low pressure side ensures that the correct amount of refrigerant is added to the system and helps maintain the proper functioning of the equipment.

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51. WHY SHOULD YOU CHARGE WITH VAPOR?

Explanation

Charging with liquid can cause water to freeze in the tubes, which can lead to blockages and damage to the system.

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52. WHAT WOULD HAPPEN IF THE SPRING IN THE TEV WERE TO BREAK?

Explanation

If the spring in the TEV were to break, it would result in flooding the evaporator. This means that an excessive amount of refrigerant would enter the evaporator, causing it to become overwhelmed and unable to effectively cool the air. This can lead to a decrease in system efficiency and potentially cause damage to the components of the evaporator.

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53. IF YOU WERE RUNNING THREE COMPRESSORS, WHICH BEST DESCRIBES THE STATE OF REFRIGERANT LEAVING THE THIRD COMPRESSOR?

Explanation

When running three compressors, the refrigerant leaving the third compressor would be in a highly superheated vapor state. This means that the refrigerant has been heated above its saturation temperature, resulting in a gas-like state with no liquid present. Superheating occurs when the refrigerant absorbs additional heat after it has completely evaporated, leading to an increase in temperature. In this case, the refrigerant leaving the third compressor has undergone significant superheating, indicating that it is mostly in a vapor form with very little or no liquid content.

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54. TXV POWER HEADS ARE COLOR CODED TO MATCH REFRIGERANT CHARGE IN THE SYSTEM.  WHAT COLOR WOULD THE POWER HEAD HAVE IF IT WAS CHARGE WITH R-22?

Explanation

The power head of a TXV (Thermostatic Expansion Valve) is color-coded to match the refrigerant charge in the system. Since R-22 refrigerant is commonly associated with the color green, the power head would be green if it was charged with R-22.

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55. A CONSTANT PRESSURE EXPANSION VALVE IS BEING USED INSTEAD OF A THERMOSTATIC EXPANSION VALVE UNDER VARIOUS LOADS WILL:

Explanation

Using a constant pressure expansion valve instead of a thermostatic expansion valve under various loads will result in both starving and flooding the evaporator. A constant pressure expansion valve does not regulate the flow of refrigerant based on the temperature of the evaporator, leading to inconsistent refrigerant flow. This can cause the evaporator to be starved of refrigerant, leading to poor cooling performance. On the other hand, it can also result in excessive refrigerant flow, causing the evaporator to flood and potentially lead to liquid refrigerant entering the compressor, which can cause damage. Therefore, both options A and B are correct.

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56. SHELL AND TUBE CONDENSERS HAVE THE ADVANTAGE OF:

Explanation

Both A and B are correct because shell and tube condensers have the advantage of being able to remove the heads for cleaning the water sides of the tubes, as well as not having to disrupt the refrigerant connections. This allows for easier maintenance and cleaning of the condenser, ensuring optimal performance and efficiency.

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57. A RECIPROCATING REFRIGERATION COMPRESSOR CYLINDER HAS A 12" BORE AND 16" STROKE, THE VOLUME OF REFRIGERANT IN CUBIC INCHES WOULD BE CLOSER TO

Explanation

The volume of a cylinder can be calculated using the formula V = πr^2h, where V is the volume, r is the radius, and h is the height. In this case, the radius is half of the bore, so it is 6 inches. The height is the stroke, so it is 16 inches. Plugging these values into the formula, we get V = π(6^2)(16) = 1808 cubic inches. Therefore, the volume of refrigerant in cubic inches would be closer to 1808.

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58. A JET EJECTOR IS USED TO RAISE OIL MIXED WITH REFRIGERANT WHICH HAS COLLECTED AT THE BOTTOM OF THE EVAPORATOR.  IF RESTRICTED

Explanation

If the flow of oil is restricted, it means that there is not enough pressure or force to lift the oil mixed with refrigerant. This results in insufficient head, which refers to the pressure difference needed to lift the oil. As a result, the oil will not be able to be lifted from the bottom of the evaporator.

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59. MULTISTAGE CENTRIFUGAL COMPRESSOR EACH STAGE:

Explanation

In a multistage centrifugal compressor, the tip speed refers to the speed at which the outer edge of the impeller rotates. The given answer states that the tip speed is more with each stage. This means that as the refrigerant passes through each stage of the compressor, the impeller rotates at a higher speed. This increase in tip speed helps to increase the pressure and velocity of the refrigerant, resulting in a higher compression ratio and improved efficiency.

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60. UNLOADERS ARE USED TO:

Explanation

Unloaders are used to reduce capacity in a refrigeration system. They are designed to control the flow of refrigerant and adjust the system's capacity based on the cooling load requirements. By reducing the capacity, unloaders help maintain the system's efficiency and prevent overcooling. They achieve this by bypassing a portion of the refrigerant flow when the cooling demand is low, allowing the compressor to run at a lower capacity. This helps save energy and ensures optimal performance of the refrigeration system.

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61. DURING A WALK THROUGH OF THE ENGINE ROOM THE RMO NOTICES EXCESSIVE SUPERHEAT AT THE EVAPORATOR OUTLET, THIS WOULD MOST LIKELY BE CAUSED BY:

Explanation

Excessive superheat at the evaporator outlet can be caused by any of the mentioned options. A starved evaporator occurs when there is insufficient refrigerant flow, resulting in high superheat. A leak in the system can cause a decrease in refrigerant charge, leading to inadequate cooling and high superheat. Similarly, a low refrigerant charge can cause insufficient cooling and high superheat. Therefore, any of these factors can contribute to excessive superheat at the evaporator outlet.

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62. A PRESSURE RELIEF VALVE THAT IS INSTALLED ON A RECIPROCATING COMPRESSOR USING R-12 IS NORMALLY SET:

Explanation

The correct answer is "ACCORDING TO DESIGN PRESSURE". When installing a pressure relief valve on a reciprocating compressor using R-12, it is typically set according to the design pressure. This means that the valve is adjusted to open and release pressure when the system reaches the predetermined maximum pressure that the compressor is designed to handle. Setting the relief valve according to the design pressure helps to ensure the safe operation of the compressor and prevent overpressure situations that could damage the equipment or pose a safety risk.

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63. REFRIGERANTS ARE CHARACTERIZED BY THE PHYSICAL AND CHEMICAL PROPERTIES INCLUDING LATENT HEAT, BOILING POINT, REFRIGERATION EFFECT AND OTHERS.  OF THE REFRIGERANTS IN COMMERCIAL INDUSTRIES USED TODAY, THE ONE WITH THE HIGHEST LATENT HEAT AND REFRIGERATION EFFECT:

Explanation

Ammonia is the refrigerant with the highest latent heat and refrigeration effect among the refrigerants used in commercial industries today. This means that ammonia has a high capacity to absorb and release heat during the refrigeration process, making it an efficient refrigerant. Ammonia's high latent heat allows it to absorb a significant amount of heat energy when it evaporates, while its high refrigeration effect enables it to provide effective cooling. Therefore, ammonia is preferred in industrial refrigeration systems where large cooling capacities are required.

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64. THE RUPTURE DISK IS ALWAYS PIPED INTO THE

Explanation

The rupture disk is always piped into the low side of the system. This is because the low side of the system operates at a lower pressure compared to the high side. The rupture disk is designed to burst and release pressure when it exceeds a certain limit. By piping it into the low side, it ensures that the excess pressure is safely vented without causing damage to the system or posing any safety risks.

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65. IF YOU HAVE 62 PSI AT 35°F AND 70 PSI AT 45°F, WHAT WOULD 38°F BE?

Explanation

The given question is asking for the pressure at 38°F based on the given pressures at 35°F and 45°F. We can observe that as the temperature increases, the pressure also increases. Therefore, we can infer that the pressure at 38°F would be between 62 PSI and 70 PSI. The closest option to this range is 64.4 PSI, which is the correct answer.

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66. IF THE ELIMINATOR PLATES LOCATED BELOW THE FAN IN AN INDUCED DRAFT-COOLING TOWER HAVE BECOME CLOGGED, OF THE FOLLOWING THIS WOULD MOST LIKELY RESULT IN: 

Explanation

If the eliminator plates located below the fan in an induced draft-cooling tower have become clogged, it would most likely result in an increase in cooling tower water temperature being returned. The eliminator plates are responsible for removing water droplets from the air leaving the cooling tower. If they become clogged, the water droplets will not be effectively removed, leading to a higher water temperature being returned to the cooling tower. This can negatively impact the cooling efficiency of the tower and potentially cause other issues in the cooling system.

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67. SUPERHEATED VAPOR PROTECTS THE COMPRESSOR AGAINST LIQUID INTAKE.  WHAT WOULD THE RMO NOTICE IF COMPRESSOR WAS RECEIVING LIQUID?

Explanation

If the compressor was receiving liquid, the RMO (Refrigeration Machine Operator) would notice that frost may develop in the suction line. This is because when liquid enters the compressor, it can cause a drop in temperature and lead to the formation of frost in the suction line. This is a sign of potential damage to the compressor and can decrease the efficiency of the refrigeration system.

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68. LOW CONDENSING PRESSURE IS NOT GOOD BECAUSE

Explanation

When the condensing pressure is low, it means that the pressure in the condenser is not sufficient to properly condense the refrigerant vapor into liquid form. This leads to a decrease in the liquid level in the condenser, causing the expansion valves to not be able to feed the refrigerant properly. As a result, the expansion valves will not be able to regulate the flow of refrigerant into the evaporator effectively, leading to inefficient cooling.

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69. WHEN OPERATING A REFRIGERATION MACHINE CONDENSER USING R-22 REFRIGERANT, UNDER NORMAL CONDITIONS THE OPERATOR OBSERVES THAT THE COOLING WATER IS BEING SUPPLIED AT 85°F AND LEAVING AT 95°F.  GIVEN THIS INFORMATION, THE CORRESPONDING COMPRESSOR HEAD PRESSURE IN PSI SHOULD BE MOST NEARLY:

Explanation

The correct answer is 213 psi because the head pressure of a refrigeration machine condenser is directly related to the temperature of the cooling water. As the cooling water temperature increases, the head pressure also increases. In this case, the cooling water is being supplied at 85°F and leaving at 95°F, indicating a temperature rise of 10°F. Based on industry standards and guidelines, a temperature rise of 10°F corresponds to a head pressure of approximately 213 psi.

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70. A BIMETAL DISK OR KLIXON IS USED TO

Explanation

The bimetal disk or klixon is used to protect the wiring and components against excessive current draw. When the current draw exceeds a certain limit, the bimetal disk or klixon will trip and open the circuit, preventing further damage to the wiring and components. This helps to prevent overheating and potential electrical fires.

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71. WHAT IS THE DISADVANTAGE OF HAVING A LOW HEAD PRESSURE?

Explanation

A low head pressure in a refrigeration system can cause the expansion valve to not feed properly. The expansion valve is responsible for regulating the flow of refrigerant into the evaporator. If the head pressure is too low, there may not be enough force to push the refrigerant through the expansion valve, resulting in inadequate cooling and potentially causing the evaporator to not receive the proper amount of refrigerant. This can lead to inefficient cooling and reduced performance of the refrigeration system.

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72. UPON BEING ASSIGNED TO A FACILITY DURING INSPECTION OF THE FACILITY, YOU FIND THERE HAS BEEN FAILURE TO MAINTAIN WATER TREATMENT.  INSPECTING THE CONDENSER WATER, THE FIRST EVIDENCE WOULD MOST LIKELY BE:

Explanation

Upon being assigned to a facility during inspection, if there has been a failure to maintain water treatment, the first evidence that would most likely be observed when inspecting the condenser water is an increase in compressor head pressure. This is because the failure to maintain water treatment can lead to the accumulation of contaminants in the condenser water, which can reduce the efficiency of heat transfer. As a result, the compressor needs to work harder to maintain the desired pressure, leading to an increase in head pressure.

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73. DURING A PARTICULAR ROUND AN OPERATOR NOTICES THAT THE SUCTION LINE AND PART OF THE COMPRESSOR ARE FROSTED, THE MOST LIKELY CAUSE OF THE CONDITION IS

Explanation

The most likely cause of the frost formation on the suction line and compressor is that the expansion valve is open too wide. When the expansion valve is open too wide, it allows too much refrigerant to flow through the evaporator coil, causing the evaporator coil to become too cold. This can lead to frost formation on the suction line and compressor.

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74. AN OPERATOR IS USING A SLING PSYCHROMETER TO MEASURE DRY AND WET BULB TEMP ON A ROOF OF A BUILDING WHERE THE COOLING TOWER IS LOCATED.  IF DURING THE DAY THE TEMP REMAINS CONSTANT, AND WET BULB DROPS BY 5°F, AND ALL OTHER CONDITIONS REMAIN UNCHANGED, THE OPERATOR SHOULD SEE:

Explanation

If the wet bulb temperature drops by 5°F while the dry bulb temperature remains constant, it indicates a decrease in the amount of moisture in the air. This decrease in moisture will result in a lower cooling water temperature return. As the air becomes drier, it will have less of a cooling effect on the water, causing a lower temperature return. Therefore, the operator should expect to see a lower cooling water temperature return in this scenario.

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75. A VERTICAL 12" WATER PIPE FROM THE ROOF HAS A PRESSURE GAUGE READING OF 120 PSI.  HOW TALL IS THE PIPE?

Explanation

The pressure gauge reading of 120 PSI indicates the pressure at the bottom of the vertical water pipe. Since pressure in a fluid is directly proportional to the height of the fluid column, we can use the equation P = ρgh, where P is the pressure, ρ is the density of the fluid, g is the acceleration due to gravity, and h is the height of the fluid column. By rearranging the equation to solve for h, we get h = P/(ρg). Since the density of water is approximately constant, the height of the water column is directly proportional to the pressure. Therefore, the height of the pipe is 277 feet.

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76. 1000 BTU'S ARE REMOVED FROM 100 POUNDS OF WATER AT A TEMPERATURE OF 55°F.  WHAT IS THE FINAL WATER TEMPERATURE?

Explanation

When 1000 BTU's are removed from 100 pounds of water at a temperature of 55°F, the final water temperature will be 45°F. This is because the removal of heat energy causes the water to cool down, resulting in a decrease in temperature.

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77. A FUSIBLE PLUG MELTS AT

Explanation

A fusible plug is designed to melt at a specific temperature in order to prevent excessive pressure build-up in a system. In this case, the correct answer is 450°F, which means that the fusible plug will melt and release pressure when the temperature reaches 450°F. This temperature is lower than the other options provided, indicating that the system requires a lower temperature threshold for pressure relief.

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78. YOU HAVE BEEN INFORMED THAT THE O.A.T. HAS DROPPED 10°C.  THE TEMPERATURE IN °F IS

Explanation

To convert Celsius to Fahrenheit, we use the formula F = (C x 9/5) + 32. In this case, the temperature dropped by 10°C. Plugging in the value into the formula, we get F = (10 x 9/5) + 32 = 18. Therefore, the temperature in °F is 18.

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79. OF THE FOLLOWING THE MOST UNDESIRABLE PROPERTY IN REFRIGERANT IS

Explanation

Low latent heat is the most undesirable property in a refrigerant because latent heat is the amount of heat energy absorbed or released during a phase change, such as during the evaporation or condensation process in a refrigeration cycle. A low latent heat means that the refrigerant will absorb or release less heat energy during these phase changes, which will result in poor cooling efficiency. This will require the compressor to work harder and consume more energy to achieve the desired cooling effect, making it less efficient and cost-effective.

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80. HEAT TRANSFER RATE IN THE CONDENSER WILL

Explanation

The heat transfer rate in the condenser will increase with the velocity of the water in the tubes because higher water velocity promotes better heat transfer. When the water flows faster through the tubes, it increases the turbulence and improves the heat transfer coefficient. This results in a higher heat transfer rate between the hot vapor and the cooling water, leading to increased efficiency in the condenser.

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81. WHEN CHARGING A SYSTEM WITH LIQUID REFRIGERANT WITH A SET OF MANIFOLD GAUGES, WHAT POSITION ARE THE VALVES ON THE MANIFOLD?

Explanation

When charging a system with liquid refrigerant using a set of manifold gauges, the valves on the manifold should be in the position of HIGH SIDE BACKSEATED and LOW SIDE FRONTSEATED. This means that the valve on the high side of the manifold should be closed or turned counterclockwise until fully closed, while the valve on the low side of the manifold should be open or turned clockwise until fully open. This configuration allows for the proper flow of refrigerant into the system without any backflow or leakage.

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82. ON THE LIQUID LINE, WHICH IS THE CORRECT ORDER OF THE PLACEMENT OF ACCESSORIES?

Explanation

The correct order of the placement of accessories on the liquid line is drier, solenoid valve, and sight-glass. The drier is typically placed first in the line to remove any moisture or contaminants from the refrigerant. The solenoid valve is then installed after the drier to control the flow of refrigerant. Finally, the sight-glass is placed after the solenoid valve to allow for visual inspection of the refrigerant flow.

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83. THE BULB TO A TXV HAS FALLEN OFF AND THE ROOM IS AT 85°F.  THE EVAPORATOR WOULD?

Explanation

If the bulb to a TXV (Thermal Expansion Valve) has fallen off and the room is at 85°F, the evaporator would flood. The TXV is responsible for regulating the flow of refrigerant into the evaporator coil based on the temperature sensed by the bulb. Without the bulb, the TXV cannot accurately control the refrigerant flow, causing an excessive amount of refrigerant to enter the evaporator coil. This leads to flooding, where the evaporator is overwhelmed with refrigerant, resulting in poor heat transfer and reduced cooling capacity.

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84. WHILE MONITORING THE OPERATION OF A RECIPROCATING REFRIGERATING UNIT YOU OVERSEE THAT THE CYCLING TIMES ARE NORMAL, COMPRESSOR COMPRESSION AND TEMP ARE THE ONLY READING THAT ARE OUTSIDE THE NORMAL RATE.  UNDER THESE CONDITIONS SERVICE REQUIREMENTS WOULD INDICATE INSPECTING FOR

Explanation

Based on the information given, the cycling times of the reciprocating refrigerating unit are normal, but the compressor compression and temperature readings are outside the normal rate. This suggests that there may be an issue with the compressor valves. Faulty compressor valves can cause abnormal compression and temperature readings, indicating a problem with the valves' ability to properly control the flow of refrigerant. Therefore, inspecting for faulty compressor valves would be the appropriate service requirement in this situation.

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85. THE SOLENOID UNLOADERS ON RECIPROCATING COMPRESSORS ARE DESIGNED TO UNLOAD:

Explanation

The solenoid unloaders on reciprocating compressors are designed to unload the clearance spaces in the cylinders. When the compressor is unloaded, the solenoid unloaders open the clearance spaces to allow the compressed air to escape, reducing the pressure in the cylinders. This prevents the compressor from continuously compressing air and allows it to operate more efficiently. By unloading the clearance spaces, the compressor can control its capacity by adjusting the amount of air being compressed and prevent excessive pressure buildup.

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86. LIQUID LEVEL GAUGES (EXCEPT BULL'S EYE TYPE) SHALL HAVE SHUT OFF VALVES:

Explanation

Liquid level gauges, except for bull's eye type, should have shut off valves that can be operated both manually and automatically. This means that the shut off valves can be closed either by manually turning a handle or by an automatic mechanism. Having both manual and automatic shut off valves ensures that the liquid level can be controlled and stopped in case of emergencies or maintenance requirements. This allows for greater flexibility and safety in operating and maintaining the liquid level gauges.

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87. WHY CAN'T YOU USE A FLARE FITTING 3/4" OR LARGER?

Explanation

A flare fitting that is 3/4" or larger cannot be used because it cannot be tightened enough to create a good seal. Flare fittings rely on compression to form a tight seal, and larger fittings require more force to achieve this compression. Therefore, it is easier and more effective to use other methods, such as sweating or soldering, for larger fittings.

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88. A ROOM THERMOSTAT CONTROLS THE LIQUID LINE SOLENOID VALVE IN THIS COMMERCIAL REFRIGERATION SYSTEM.  THE COMPRESSOR IS ACTIVATED BY:

Explanation

The compressor in this commercial refrigeration system is activated by the low side pressure stat. The low side pressure stat is responsible for monitoring and controlling the pressure on the suction or low-pressure side of the system. When the pressure drops below a certain set point, the low side pressure stat signals the compressor to turn on and start compressing refrigerant gas. This helps maintain the desired pressure and temperature levels in the system.

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89. FLOODED EVAPORATORS HAVE HIGH HEAT TRANSFER PER SQUARE FOOT, WHAT MAY BE A DISADVANTAGE?

Explanation

Flooded evaporators have high heat transfer per square foot, which means they are efficient at transferring heat. However, a disadvantage of flooded evaporators is that they require a higher refrigerant charge. This means that more refrigerant is needed to operate the system, which can be costly and may have environmental implications.

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90. WHEN CONDUCTING A ROUTINE TOUR OF PLANT OPERATION A RMO OBSERVES A SIGNIFICANT INCREASE IN SUPERHEAT TEMP.  FOR THE REFRIGERATING FLUID ENTERING A RECIPROCATING COMPRESSOR.  OF THE FOLLOWING THE MOST LIKELY CAUSE FOR THIS CONDITION IS

Explanation

The most likely cause for the significant increase in superheat temperature for the refrigerating fluid entering a reciprocating compressor is scale particles lodged in the TEV valve. Scale particles can obstruct the flow of refrigerant and disrupt the normal operation of the thermal expansion valve (TEV), leading to improper regulation of the refrigerant flow and an increase in superheat temperature. This can result in inefficient cooling and potential damage to the compressor.

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91. IF THE SUCTION PRESSURE IS 60 PSIG AND THE DISCHARGE 180 PSIG, WHAT WOULD THE COMPRESSION RATIO BE?

Explanation

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92. THE MOST IMPORTANT REASON TO USE 2 COMPRESSORS IN A CASCADE SYSTEM IS TO:

Explanation

Using two compressors in a cascade system allows for the accomplishment of lower temperatures. The cascade system consists of two separate refrigeration cycles, with each compressor operating at different temperature levels. The lower temperature cycle is used to cool the higher temperature cycle, resulting in lower overall temperatures. This is beneficial in applications where extremely low temperatures are required, such as in scientific research or industrial processes. By dividing the cooling load between two compressors, the cascade system can achieve lower temperatures more efficiently and effectively.

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93. A RUPTURE DISC IN A CENTRIFUGAL REFRIGERATING MACHINE IS NORMALLY LOCATED ON THE

Explanation

A rupture disc in a centrifugal refrigerating machine is normally located on the evaporator. The evaporator is responsible for absorbing heat from the surroundings and turning the refrigerant into a low-pressure gas. If there is a sudden increase in pressure or a malfunction in the system, the rupture disc on the evaporator will burst, allowing the excess pressure to be released and preventing any damage to the machine. This ensures the safety and proper functioning of the refrigerating machine.

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94. AT THE PLANT WHERE YOU ARE EMPLOYED A REFRIGERATING UNIT IS BEING TAKEN OUT OF SERVICE FOR MAJOR REPAIRS AND THAT YOU HAVE BEEN ASSIGNED TO WITHDRAW REFRIGERANT FOR STORAGE IN A 40 GALLON CONTAINER.  ACCORDING TO THE NYC FIRE HANDBOOK, THE MAXIMUM QUANTITY OF REFRIGERANT IN GALLONS THAT YOU MAY LEGALLY FILL EACH CONTAINER WITH UNDER ANY CIRCUMSTANCES IS:

Explanation

According to the NYC Fire Handbook, the maximum quantity of refrigerant in gallons that can be legally filled in each container under any circumstances is 30.

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95. WHAT IS THE PURPOSE OF THE EQUALIZER LINE?

Explanation

The purpose of the equalizer line is to make up for the pressure drop in the evaporator. As refrigerant flows through the evaporator, there is a decrease in pressure due to the cooling process. The equalizer line allows for the equalization of pressure between the evaporator and the rest of the system, ensuring that the proper amount of refrigerant is metered and preventing any significant pressure drop.

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96. WHAT IS 29.92" HG IN KPA

Explanation

The correct answer is 101.3. This is because 29.92" Hg is the standard atmospheric pressure at sea level in inches of mercury, and 1 inch of mercury is equivalent to 3.38639 kilopascals. Therefore, 29.92" Hg can be converted to 101.3 kilopascals.

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97. THE MECHANISM SITTING ABOVE THE CONDENSER IS KNOWN AS

Explanation

The mechanism sitting above the condenser in a refrigeration system is known as the economizer. The economizer is responsible for improving the overall efficiency of the refrigeration cycle by utilizing the waste heat from the compressor to preheat the refrigerant before it enters the condenser. This helps in reducing the energy consumption of the system.

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98. WHAT SHAFT SEAL PREVENTS VAPOR FROM LEAKING OUT OF COMPRESSOR?

Explanation

A stuffing box is a type of shaft seal that prevents vapor from leaking out of a compressor. It is a traditional sealing method that uses packing material, such as braided rope or graphite, to create a seal around the shaft. This prevents vapor from escaping and helps maintain the efficiency and performance of the compressor.

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99. YOU ARE AN RMO ASSIGNED TO THE 3RD FLOOR IN AN ASSEMBLY ROOM.  ATTENDANCE AND TEMP HAVE INCREASED DURING THE AFTERNOON, THEREFORE A COLDER WATER SUPPLY IS TO BE PRODUCED.  IN ORDER TO ACCOMPLISH THIS YOU SHOULD.

Explanation

To produce colder water supply, the RMO should lower the compressor suction operating pressure. By reducing the suction pressure, the compressor will draw in less heat from the surrounding air, resulting in a colder water supply. Re-adjusting the TEV superheat setting, deactivating the freeze stat, or raising the compressor discharge operating pressure would not directly affect the temperature of the water supply.

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100. IF YOU ARE USING A PORTABLE COMPRESSOR RECOVERY UNIT TO REMOVE VAPOR.  WHAT WOULD HAPPEN WHEN YOU ARE RECOVERING?

Explanation

When using a portable compressor recovery unit to remove vapor, the vapor density will decrease. This is because the compressor recovery unit is designed to remove vapor from a system, thereby reducing the concentration or density of vapor in the system.

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101. IN AN OPERATING PLANT USING RECIPROCATING COMPRESSORS, THE EFFICIENCY OF ONE OF THE COMPRESSORS HAS DECREASED.  ONE OF THE FOLLOWING MAY BE THE CAUSE OF THIS

Explanation

A possible explanation for the correct answer, "LEAK IN THE SUCTION VALVE," is that a leak in the suction valve can cause a decrease in the efficiency of the compressor. When there is a leak, the compressor may not be able to draw in the required amount of gas, leading to a decrease in the compression ratio and overall efficiency. This can result in reduced performance and increased energy consumption.

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102. IF A CENTRIFUGAL COMPRESSOR IS BEING USED IN A REFRIGERATION SYSTEM, AND IS AFFECTED BY THE CONDENSER, THE CONDENSER MAY BE IMPROVED BY:

Explanation

Increasing the amount of sub-cooling in the condenser of a refrigeration system can improve the performance of a centrifugal compressor. Sub-cooling refers to the process of cooling the refrigerant below its saturation temperature, which helps to remove additional heat from the refrigerant before it enters the compressor. By increasing the amount of sub-cooling, the temperature of the refrigerant entering the compressor is lower, which improves the compressor's efficiency and reduces the risk of damage due to overheating. This ultimately leads to better overall performance of the refrigeration system.

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103. AT THE CONDENSER, REFRIGERANT ENTERS AS

Explanation

The correct answer is "HIGH PRESSURE GAS AND LEAVES AS HIGH PRESSURE LIQUID." This is because the condenser is the component in a refrigeration system where the refrigerant, in its gaseous state and under high pressure, releases heat and condenses into a high-pressure liquid. This high-pressure liquid is then sent to the expansion valve to continue the refrigeration cycle.

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104. ASSUME AN OPERATOR IS ABLE TO OBSERVE R-11, WATER AND LUBRICATING OIL TOGETHER AT 70°F.  UNDER THESE CONDITIONS, THE WATER, MOISTURE, AND FLUIDS WOULD SETTLE IN THE CONTAINER FROM TOP TO BOTTOM IN WHAT ORDER?

Explanation

Water, being denser than the refrigerant, would settle at the bottom. The refrigerant would occupy the middle layer, and the lubricating oil, being less dense than both, would float on top. Therefore, the correct order is water, refrigerant, and then oil.

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105. WHEN OPERATING A REFRIGERATION UNIT, THE OPERATOR NOTICES THAT THE MOTOR COMPRESSOR IS SHORT CYCLING, THE UNIT IS USING A LOW SIDE FLOAT VALVE.  THE FOLLOWING SERVICE REQUIREMENTS WOULD INDICATE

Explanation

The correct answer suggests that when a refrigeration unit with a low side float valve is experiencing short cycling of the motor compressor, the operator should consider adding additional refrigerant. This is because short cycling can be caused by a low refrigerant charge, which leads to inadequate cooling and causes the compressor to turn on and off frequently. By adding more refrigerant, the system can achieve the proper charge and prevent short cycling.

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106. AN RMO OBSERVES A GAUGE THAT READS THE SATURATION PRESSURE OF A REFRIGERANT.  IF CHILLED WATER IS BEING CIRCULATED AS THE COOLING MEDIUM, THIS READING CAN BEST BE USED TO ESTIMATE THE:

Explanation

The saturation pressure of a refrigerant can be used to estimate the temperature of the chilled water being pumped to the building spaces that are being cooled. The saturation pressure of the refrigerant is directly related to its temperature, so by observing the gauge reading, the RMO can determine the temperature of the chilled water.

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107. FROST APPEARING ON THE SUCTION LINE AND PART OF THE COMPRESSOR IS CAUSED BY?

Explanation

Frost appearing on the suction line and part of the compressor is caused by a flooded evaporator. When the evaporator is flooded, excess liquid refrigerant enters the compressor, causing the temperature of the compressor to drop below freezing. This leads to the formation of frost on the suction line and compressor.

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108. CONCERNING LEAKAGE, WHICH STATEMENT IS MOST CORRECT?

Explanation

Gate valves cause more leakage because they have a design that allows for a larger flow area when fully open, but when partially closed, the flow area is reduced, creating turbulence and increasing the chance of leakage. Globe valves, on the other hand, have a more restrictive flow path, which reduces the chance of leakage. Therefore, the statement "Gate valves cause more leakage" is the most correct.

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109. ASSUME THAT THE OPERATOR HAS A CHOICE OF 4 VALVES TO SELECT FROM AND WANTS TO MINIMIZE PRESSURE DROP.  OF THE FOLLOWING THE OPERATOR SHOULD AVOID THE USE OF:

Explanation

The operator should avoid using the globe valve because it typically has a higher pressure drop compared to the other options. Globe valves have a more complex design with a curved flow path, which causes more resistance to flow and results in a higher pressure drop. In contrast, ball, plug, and gate valves have a more streamlined flow path, allowing for lower pressure drop. Therefore, to minimize pressure drop, the operator should avoid using the globe valve.

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110. SHELL AND COIL CONDENSERS HAVE THE ADVANTAGE OF:

Explanation

Shell and coil condensers have the advantage of having less chance of developing leaks. This means that compared to other types of condensers, shell and coil condensers are less likely to experience leaks in the long run. This is beneficial because leaks can lead to a loss of refrigerant and a decrease in system efficiency. By having less chance of developing leaks, shell and coil condensers offer improved reliability and performance.

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111. AN OPERATOR IS RUNNING TWO CENTRIFUGAL CONDENSER PUMPS IN PARALLEL, ONE OF THE PUMPS IS AT MAXIMUM PUMPING RATE, IF THE OPERATOR THROTTLES BACK ON THE DISCHARGE VALVE OF THE OTHER PUMP, THE MOST LIKELY EFFECT WOULD BE

Explanation

If the operator throttles back on the discharge valve of the other pump, it would result in a reduction in the total flow rate to the condenser. This is because by throttling back on the valve, the operator is restricting the flow of water from the pump, thereby reducing the overall flow rate.

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112. AN OPERATOR HAS BEEN ASSIGNED TO A LARGE RECIPROCATING MACHINE WITHOUT UNLOADERS OF THE FOLLOWING SAFETY PROPER PROCEDURE FOR STARTING MACHINE IS. 

Explanation

The correct answer is "Suction valve and discharge bypass both open". This is the proper procedure for starting the machine without unloaders. By opening the suction valve, the machine can draw in the necessary fluid. By opening the discharge bypass, the fluid can bypass the machine until it reaches the desired pressure or flow rate. This allows the machine to start up safely and prevents any damage or overload to the reciprocating machine.

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113. AN INLINE REFRIGERANT CLEANING SYSTEM IS ADVISABLE BECAUSE:

Explanation

An inline refrigerant cleaning system is advisable because refrigerant reacts with the lubrication oil. This means that if the refrigerant is not properly cleaned, it can contaminate the lubrication oil, leading to decreased efficiency and potential damage to the system. By using an inline cleaning system, any contaminants or impurities in the refrigerant can be effectively removed before it comes into contact with the lubrication oil, ensuring the smooth operation and longevity of the refrigeration system.

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114. CONVERT 18" VACUUM TO PSIA

Explanation



The conversion of 18 inches of vacuum to psia is approximately 8.85. This is determined by applying the conversion factor of 1 psi being equivalent to approximately 2.036 inches of mercury. Therefore, 18 inches of vacuum corresponds to around 8.85 psia.
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115. AS THE RMO ASSIGNED TO THE FACILITY YOU ARE INSTRUCTED TO STORE ADDITIONAL REFRIGERANT DRAWN IN THE MACHINERY ROOM, DURING COLD WEATHER TO ELIMINATE THE REFRIGERATING UNIT.  IF THERE IS A TOTAL OF 1000 LBS OF REFRIGERANT THAT HAS BEEN CHARGED TO THE REFRIGERATION MACHINE, ACCORDING TO THE NYC FIRE LAW HANDBOOK, THE MAXIMUM QUANTITY IN LBS YOU MAY LEGALLY STORE IN THE ROOM IS:

Explanation

According to the NYC Fire Law Handbook, the maximum quantity of refrigerant that can be legally stored in the machinery room is 200 pounds.

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116. CONVERT 20 PSIG TO Hg ABSOLUTE

Explanation

The correct answer is 70 because PSIG is a unit of pressure relative to atmospheric pressure, while Hg absolute is a unit of pressure relative to a vacuum. To convert PSIG to Hg absolute, you need to add the atmospheric pressure to the PSIG value. Since atmospheric pressure is typically around 14.7 PSI, adding this to 20 PSIG gives a total of 34.7 PSI. Converting 34.7 PSI to Hg absolute gives a value of approximately 70 Hg absolute.

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117. WHEN WILL THE BTUs ABSORBED BY THE CONDENSING WATER BE THE GREATEST?

Explanation

The BTUs absorbed by the condensing water will be the greatest when the condenser temperature is high and the condenser water temperature is low. This is because a high condenser temperature means that the refrigerant has a higher temperature difference with the water, allowing for more heat transfer. Additionally, a low condenser water temperature means that the water can absorb more heat from the refrigerant. Therefore, the combination of a high condenser temperature and a low condenser water temperature maximizes the heat transfer and results in the greatest amount of BTUs absorbed by the condensing water.

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118. EFFICIENCY OF THE REFRIGERATION CYCLE IS AFFECTED BY THE OPERATION OF THE CONDENSER.  OF THE FOLLOWING A MORE EFFICIENT OPERATION OF A CENTRIFUGAL COMPRESSOR RESULTS FROM:

Explanation

Lowering the condenser pressure results in a more efficient operation of a centrifugal compressor. When the condenser pressure is lowered, the temperature at which the refrigerant condenses decreases. This allows for a larger temperature difference between the condensing temperature and the evaporating temperature, which improves the overall efficiency of the refrigeration cycle.

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119. AN OPERATOR IS USING A PORTABLE RECOVERY VESSEL AND COMPRESSOR TO RECOVER VAPOR REFRIGERANT FROM A MACHINE.  THE RECOVERY PROCESS WILL SLOW DOWN BECAUSE:

Explanation

The recovery process will slow down because the refrigerant pressure will decrease. When the pressure of the refrigerant decreases, it will take longer for the compressor to recover the vapor refrigerant from the machine. This is because the compressor needs a certain level of pressure to effectively and efficiently recover the refrigerant. With a decrease in pressure, the compressor will have to work harder and take more time to recover the refrigerant.

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120. OF THE FOLLOWING, UNDER WHAT CONDITIONS OF THE HEAT IN BTU/PER MIN ABSORBED BY THE CONDENSER WATER IN A REFRIGERATING PLANT IS GREATER?

Explanation

The heat in BTU per minute absorbed by the condenser water in a refrigerating plant is greater under the condition of low evaporative temperature and high condenser temperature1. This is because the heat transfer in a refrigeration cycle is driven by the temperature difference between the refrigerant and the surrounding medium (in this case, the condenser water). A low evaporative temperature means the refrigerant absorbs less heat, and a high condenser temperature means it can reject more heat to the condenser water. Therefore, these conditions would result in the greatest heat absorption by the condenser water.

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121. ASSUMING ALL CONIDITIONS ARE REMAIN CONSTANT, THE HP PER TON OF REFRIGERATING EFFECT WOULD MOST LIKELY BE

Explanation

As the suction pressure increases, the HP per ton of refrigerating effect would most likely decrease. This is because as the suction pressure increases, the compressor has to work harder to compress the refrigerant and achieve the desired cooling effect. This increased workload leads to a decrease in efficiency, resulting in a lower HP per ton of refrigerating effect.

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COPPER USED IN REFRIGERATION SYSTEMS, LIKE IN HEAT EXCHANGERS,...
OF THE FOLLOWING THE MOST CORRECT WAY TO DESCRIBE A BRAZED JOINT IS
R-22 IS:
IN A COMPRESSOR'S ELECTRICAL BOX ONE OF THE HOT WIRES IS TOUCHING...
A MOTOR HAS 4 BELTS, THE CENTER BELT IS WORN, YOU WOULD
OF THE FOLLOWING CHARACTERISTICS OF REFRIGERANT, THE ONE THAT BEST...
AS AN RMO IN CHARGE, YOU ARE REQUESTED TO REPLACE THE GAUGE ON THE...
YOU ARE AN RMO ASSIGNED TO FACILITY WHERE A REFRIGERANT HAS BEEN...
WHEN INSTALLING A SERVICE VALVE TO ISOLATE A DUAL PRESSURE DEVICE...
WHY IS SPRING LOADED PRV BETTER TO USE THAN A FUSIBLE PLUG?
WHEN INSTALLING A PIPELINE AND YOU NEED TO MAKE A 90° ELBOW, WHICH...
SEMI-HERMETIC COMPRESSORS MAY BE BETTER TO USE THAN HERMETIC...
WHAT SAFETY GROUP DOES AMMONIA BELONG?
WHEN CHANGING WATER TO ICE, WHAT MUST BE REMOVED?
ACCORDING TO NYC FIRE CODE CLASSIFICATION OF REFRIGERANT, AMMONIA...
OF THE FOLLOWING, WHICH REFRIGERANT REQUIRES THE APPROVAL FOR USE BY...
ACCORDING TO THE SAFETY HAND BOOK, HOW MUCH REFRIGERANT CAN BE...
BECAUSE OF THE LATENT HEAT LOAD, REFRIGERATION MACHINE OPERATOR WAS...
WHAT REFRIGERANT SYSTEMS ARE MOST LIKELY TO LEAK REFRIGERANT IN...
WHEN CHARGING AN R-12 RECIPROCATING REFRIGERATION SYSTEM, AN OPERATOR...
IN A REFRIGERATION PLANT, A SMALL INDUCTION REFRIGERATION MOTOR IS...
IN AN EMERGENCY IF YOU MUST DUMP REFRIGERANT INTO SEWER, YOU WILL DUMP...
WHAT IS PURPOSE OF HAVING A SERVICE VALVE STEM CAP?
WHICH OF THE FOLLOWING ASHRAE SAFETY GROUPS IS THE MOST DANGEROUS?
Is [your statement here] true or false?
AN AUTOMATIC PURGE UNIT IS REQUIRED FOR THOSE REFRIGERATING SYSTEMS...
A RMO WOULD EXPECT A RELIEF VALVE TO START FUNCTIONING (FOR THE...
R-11 AND R-123 REFRIGERANTS ARE
AN RMO NOTICES A KNOCKING RECIPROCATING COMPRESSOR.  THE RMO IS...
THE ADVANTAGE OF FORCED DRAFT OVER NATURAL DRAFT COOLING TOWER IS:
AN OPERATOR HAS BEEN ASSIGNED TO RUN  A RECIPROCATING COMPRESSOR....
GIVEN A REFRIGERATION SYSTEM WHICH INCLUDES A FORCED DRAFT COOLING...
WHAT IS THE TEV DIAPHRAM MADE OF
IF YOU JUST PURCHASED A THERMOMETER AND NEED TO CHECK TO SEE IF ITS...
AN OPERATOR HAS BEEN ASSIGNED TO RUN A CENTRIFUGAL COMPRESSOR....
WITH RESPECT TO FIRE SAFETY, THE ANSI/ASHRAE REFRIGERANT SAFETY...
A PUMP AFFECTS THE PRESSURE OF A FLUID OR GAS BY: 
A RMO NEEDED TO VARY THE FLOW OF REFRIGERANT IN A SYSTEM.  A...
WHEN PROPERLY PURGING YOU SHOULD
WHICH IS NOT USED AS A COOLING MEDIUM IN AN INDIRECT SYSTEM
MACHINE ROOM SAFETY STANDARDS HAVE BEEN ESTABLISHED BY
ONE DISADVANTAGE IN USING BRINES AS A COOLING MEDIUM IS CORROSION....
WHICH TYPE OF PUMP IS CONSIDERED A NON-POSITIVE DISPLACEMENT PUMP?
HOW MANY BTUs WOULD BE REMOVED IN A 30 TON SYSTEM?
DUE TO A COLD FRONT, THERE WAS A SHARP DROP IN O.A.T., THE MOST LIKELY...
OF THE FOLLOWING THE MOST COMMON METERING DEVICE USED TODAY IN A...
THE AMOUNT OF REFRIGERANT THAT FLOWS THROUGH THE ORIFICE PLATE IS...
IF AN ELECTRIC MOTOR IS REWOUND TO CUT RESISTANCE BY 1/2, ALL OTHER...
ORIFICE PLATES MAY BE USED AS A METERING DEVICE COMPONENT IN A...
A RMO WAS INSTRUCTED TO CHARGE A 60 TON PLANT WITH R-134A REFRIGERANT....
WHY SHOULD YOU CHARGE WITH VAPOR?
WHAT WOULD HAPPEN IF THE SPRING IN THE TEV WERE TO BREAK?
IF YOU WERE RUNNING THREE COMPRESSORS, WHICH BEST DESCRIBES THE STATE...
TXV POWER HEADS ARE COLOR CODED TO MATCH REFRIGERANT CHARGE IN THE...
A CONSTANT PRESSURE EXPANSION VALVE IS BEING USED INSTEAD OF A...
SHELL AND TUBE CONDENSERS HAVE THE ADVANTAGE OF:
A RECIPROCATING REFRIGERATION COMPRESSOR CYLINDER HAS A 12" BORE...
A JET EJECTOR IS USED TO RAISE OIL MIXED WITH REFRIGERANT WHICH HAS...
MULTISTAGE CENTRIFUGAL COMPRESSOR EACH STAGE:
UNLOADERS ARE USED TO:
DURING A WALK THROUGH OF THE ENGINE ROOM THE RMO NOTICES EXCESSIVE...
A PRESSURE RELIEF VALVE THAT IS INSTALLED ON A RECIPROCATING...
REFRIGERANTS ARE CHARACTERIZED BY THE PHYSICAL AND CHEMICAL PROPERTIES...
THE RUPTURE DISK IS ALWAYS PIPED INTO THE
IF YOU HAVE 62 PSI AT 35°F AND 70 PSI AT 45°F, WHAT WOULD...
IF THE ELIMINATOR PLATES LOCATED BELOW THE FAN IN AN INDUCED...
SUPERHEATED VAPOR PROTECTS THE COMPRESSOR AGAINST LIQUID INTAKE....
LOW CONDENSING PRESSURE IS NOT GOOD BECAUSE
WHEN OPERATING A REFRIGERATION MACHINE CONDENSER USING R-22...
A BIMETAL DISK OR KLIXON IS USED TO
WHAT IS THE DISADVANTAGE OF HAVING A LOW HEAD PRESSURE?
UPON BEING ASSIGNED TO A FACILITY DURING INSPECTION OF THE FACILITY,...
DURING A PARTICULAR ROUND AN OPERATOR NOTICES THAT THE SUCTION LINE...
AN OPERATOR IS USING A SLING PSYCHROMETER TO MEASURE DRY AND WET BULB...
A VERTICAL 12" WATER PIPE FROM THE ROOF HAS A PRESSURE GAUGE...
1000 BTU'S ARE REMOVED FROM 100 POUNDS OF WATER AT A TEMPERATURE...
A FUSIBLE PLUG MELTS AT
YOU HAVE BEEN INFORMED THAT THE O.A.T. HAS DROPPED 10°C.  THE...
OF THE FOLLOWING THE MOST UNDESIRABLE PROPERTY IN REFRIGERANT IS
HEAT TRANSFER RATE IN THE CONDENSER WILL
WHEN CHARGING A SYSTEM WITH LIQUID REFRIGERANT WITH A SET OF MANIFOLD...
ON THE LIQUID LINE, WHICH IS THE CORRECT ORDER OF THE PLACEMENT OF...
THE BULB TO A TXV HAS FALLEN OFF AND THE ROOM IS AT 85°F....
WHILE MONITORING THE OPERATION OF A RECIPROCATING REFRIGERATING UNIT...
THE SOLENOID UNLOADERS ON RECIPROCATING COMPRESSORS ARE DESIGNED TO...
LIQUID LEVEL GAUGES (EXCEPT BULL'S EYE TYPE) SHALL HAVE SHUT OFF...
WHY CAN'T YOU USE A FLARE FITTING 3/4" OR LARGER?
A ROOM THERMOSTAT CONTROLS THE LIQUID LINE SOLENOID VALVE IN THIS...
FLOODED EVAPORATORS HAVE HIGH HEAT TRANSFER PER SQUARE FOOT, WHAT MAY...
WHEN CONDUCTING A ROUTINE TOUR OF PLANT OPERATION A RMO OBSERVES A...
IF THE SUCTION PRESSURE IS 60 PSIG AND THE DISCHARGE 180 PSIG, WHAT...
THE MOST IMPORTANT REASON TO USE 2 COMPRESSORS IN A CASCADE SYSTEM IS...
A RUPTURE DISC IN A CENTRIFUGAL REFRIGERATING MACHINE IS NORMALLY...
AT THE PLANT WHERE YOU ARE EMPLOYED A REFRIGERATING UNIT IS BEING...
WHAT IS THE PURPOSE OF THE EQUALIZER LINE?
WHAT IS 29.92" HG IN KPA
THE MECHANISM SITTING ABOVE THE CONDENSER IS KNOWN AS
WHAT SHAFT SEAL PREVENTS VAPOR FROM LEAKING OUT OF COMPRESSOR?
YOU ARE AN RMO ASSIGNED TO THE 3RD FLOOR IN AN ASSEMBLY ROOM....
IF YOU ARE USING A PORTABLE COMPRESSOR RECOVERY UNIT TO REMOVE VAPOR....
IN AN OPERATING PLANT USING RECIPROCATING COMPRESSORS, THE EFFICIENCY...
IF A CENTRIFUGAL COMPRESSOR IS BEING USED IN A REFRIGERATION SYSTEM,...
AT THE CONDENSER, REFRIGERANT ENTERS AS
ASSUME AN OPERATOR IS ABLE TO OBSERVE R-11, WATER AND LUBRICATING OIL...
WHEN OPERATING A REFRIGERATION UNIT, THE OPERATOR NOTICES THAT THE...
AN RMO OBSERVES A GAUGE THAT READS THE SATURATION PRESSURE OF A...
FROST APPEARING ON THE SUCTION LINE AND PART OF THE COMPRESSOR IS...
CONCERNING LEAKAGE, WHICH STATEMENT IS MOST CORRECT?
ASSUME THAT THE OPERATOR HAS A CHOICE OF 4 VALVES TO SELECT FROM AND...
SHELL AND COIL CONDENSERS HAVE THE ADVANTAGE OF:
AN OPERATOR IS RUNNING TWO CENTRIFUGAL CONDENSER PUMPS IN PARALLEL,...
AN OPERATOR HAS BEEN ASSIGNED TO A LARGE RECIPROCATING MACHINE WITHOUT...
AN INLINE REFRIGERANT CLEANING SYSTEM IS ADVISABLE BECAUSE:
CONVERT 18" VACUUM TO PSIA
AS THE RMO ASSIGNED TO THE FACILITY YOU ARE INSTRUCTED TO STORE...
CONVERT 20 PSIG TO Hg ABSOLUTE
WHEN WILL THE BTUs ABSORBED BY THE CONDENSING WATER BE THE GREATEST?
EFFICIENCY OF THE REFRIGERATION CYCLE IS AFFECTED BY THE OPERATION OF...
AN OPERATOR IS USING A PORTABLE RECOVERY VESSEL AND COMPRESSOR TO...
OF THE FOLLOWING, UNDER WHAT CONDITIONS OF THE HEAT IN BTU/PER MIN...
ASSUMING ALL CONIDITIONS ARE REMAIN CONSTANT, THE HP PER TON OF...
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