New Jersey Blue Seal Refrigeration Practice Exam

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• Which compressor design does not require inlet or discharge valves?
• Which refrigerant sublimates at 14.7 psia?
• What unit is commonly used to measure the energy efficiency of refrigeration systems?
• What term describes the temperature at which moisture in the air begins to condense?
• In a refrigeration system, which component is responsible for dissipating heat?
• Which refrigerant usually has a condenser pressure of 1050 psi?
• If a cooling tower circulates 4,300 GPM of water, what is the cooling capacity in tons?
• What does the internal overload of a compressor primarily sense?
• What size packing should be used for a pump with a 4" stuffing box bore and a 3 1/4" pump shaft?
• Why is a horizontal shell and tube heat exchanger preferred over a vertical one?
• How do you convert 80 degrees Celsius to degrees Fahrenheit?
• What is the primary role of insulation in refrigeration systems?
• What happens to a TXV when there is an increased load to the evaporator coil?
• What effect does scale formation have on a refrigeration system?
• How many BTUs are removed from 2000 lbs. of ice at 32 F to give ice at 28 F?
• Which devices control the high side float?
• In terms of energy savings, what is an important aspect to focus on in HVAC systems?
• If an ammonia wet compression system is replaced with a dry compression system and capacity remains the same, what is the expected outcome regarding the danger to the compressor?
• What is the cooling capacity in tons for a cooling tower circulating 2,850 GPM of water?
• If the load on the evaporator increases, what happens to the suction pressure and horsepower?
• What water chemistry test is used to determine cooling tower cycles of concentration?
• Which terminals are present on a single phase compressor?
• What type of pump is typically used to circulate brine through a refrigeration system?
• What is an implication of a dry or damaged seal in a compressor?
• What happens to the pressure in a refrigeration system when the evaporator is too cold?
• What device is utilized for capacity control on a screw type compressor?
• What would be a typical symptom of a malfunctioning thermostatic expansion valve?
• What does the term "volumetric efficiency" refer to in relation to a compressor?
• What type of heat increases the temperature of a substance without changing its state?
• Which type of refrigeration cycle is primarily used in commercial refrigeration applications?
• In a shell and tube heat exchanger, where is the refrigerant typically located?
• Which type of compressor does not require lubrication?
• What is the most common refrigerant used in domestic refrigeration applications?
• What would happen if you had a sudden drop in the temperature in the cooling tower of a lithium bromide absorption system?
• What is the calculated RPM of a four-pole motor rated at 150hp, 120 volts, and 60 cycles?
• Express Ohm's Law as a formula?
• Where is the greatest possible pressure drop typically found in a refrigeration system?
• What is the formula used to determine the number of cycles of concentration for a cooling tower?
• What does a sling psychrometer measure?
• How do the valves on a compressor operate?
• Which scale is referred to as the absolute Celsius scale?
• What is the relationship between cooling capacity and water circulation in a cooling tower?
• What is the maximum amount of refrigerant you can put in a 250 lb. cylinder?
• Which is the correct process for addressing refrigerant contamination?
• What could frost on the suction line indicate when using a high side float metering device?
• What might indicate that a refrigerant system requires maintenance related to high pressure?
• What is viscosity in the context of refrigeration oil?
• What component primarily ensures the proper flow of refrigerant in a refrigeration system?
• Why is a horizontal shell and tube condenser more efficient than a vertical shell and tube condenser?
• If a reciprocating compressor were run with the suction valve closed and the discharge valve open, what would occur?
• What is a main advantage of a cascade refrigeration system?
• What is the function of the refrigerant suction gas in a semi-hermetic reciprocating compressor?
• How do unloaders work on a reciprocating compressor?
• What type of heat exchange occurs at the exterior sides of a cooling tower?
• On a semi-hermetic compressor, where is the oil pump located?
• How should refrigeration lines be installed for optimal performance?
• Which three methods are common for heat transfer?
• In an efficiently operating system, where can flash gas typically be found?
• Which statement regarding ASHRAE standard classification of refrigerants is false?
• What would frost on the suction line of a system using a high side float indicate?
• In a system using a high side float, what controls its operation?
• Which component is crucial for preventing refrigerant leakage in a system?
• What does a high head pressure in a refrigeration system often indicate?
• What is the lowest recommended temperature for using a calcium chloride brine?
• What is the specific heat for ice compared to water and steam?
• What does the fire point of a refrigerant oil refer to?
• In an automatic expansion valve system, constant pressure is maintained at the:
• What is a common problem associated with a low refrigerant charge?
• What is the main purpose of a lantern stuffing ring in refrigeration systems?
• What is the position of the suction and discharge valves when the piston is at top dead center?
• In a single acting compressor, where is the refrigerant gas compressed?
• What determines the low side pressure in a refrigeration system?
• What effect does a high compression ratio have in a refrigeration cycle?
• What type of intercooler mixes liquid refrigerant with discharge vapor from the lower stage compressor?
• Which condition would likely result in low head pressure within a refrigeration system?
• What is the typical resistance range found in a compressor motor winding?
• How many tons of refrigerant are needed to prevent 2,000 lbs of ice from melting in 24 hours?
• Which type of compressor uses pistons to compress refrigerant gas?
• Which motor circuit is de-energized after the compressor comes up to speed?
• What type of issue can a damaged seal in a compressor create?
• The counter-flow principle is essential to which type of system?
• What is the purpose of a water jacket on refrigeration equipment?
• Define the operation of the valves of a refrigeration compressor:
• What is the primary function of a compressor in a refrigeration system?
• What is a potential consequence of overcharging a refrigerant system?
• When R-12 is superheated and enters a reciprocating compressor, it leaves as:
• A condenser water pH of 10 is considered to be:
• The static setting of a thermostatic expansion valve is measured in:
• What is the main purpose of a heat exchanger in refrigeration systems?
• Where are oil separators located in an ammonia system?
• What is the definition of the term "cloud point" in refrigeration systems?
• What is the latent heat of vaporization of water?
• What type of control mechanism is commonly used for automatically loading and unloading a compressor?
• What is the flash point of refrigeration oil?
• What is the Celsius equivalent of 5 degrees Fahrenheit?
• Which refrigerant is typically not used in the high side of a cascade refrigeration system?
• Which statement about rotary pumps is incorrect?
• If a 788,000 Btu/hr unit produces cooling, how many tons of cooling does it generate?
• How many tons of refrigeration are represented by 600,000 BTU/hr?
• How is the relationship of actual moisture vapor in the atmosphere to the maximum it can hold defined?
• What impact does having an undersized condenser have on a refrigeration system?
• What is the English unit of heat measurement?
• What does evaporation do in a refrigeration system?
• What would be the cycles of a four-pole motor rated at 150 hp, 3 phase, 90% efficient, and 1800 rpm?
• In which scenario is a refrigeration cycle considered efficient?
• What role does the expansion valve play in a refrigeration cycle?
• What is a typical issue caused by air leaking into a refrigerant system?
• As suction pressure increases, what happens to the horsepower in a refrigeration system?
• What symptom may indicate a leaking expansion valve?
• What is the material commonly used for packing in a stuffing box?
• A unit that delivers 10,000 Btu/hr would be classified as what cooling tonnage?
• What is the primary purpose of a cooling tower in HVAC systems?
• What can indicate the need for maintenance on a refrigeration system?
• Which of the following would not cause high head pressure in a refrigeration system?
• In a refrigeration system, what part would be considered the low side?
• What is the floc or cloud point in refrigeration systems?
• How does a single acting compressor operate?
• What does a high dew point indicate about the air's moisture content?
• Which of the following affects the performance of a cooling system directly?
• Which type of compressor gives the least side thrust during operation?
• What role does sufficient cooling water serve in the operation of a condenser?
• What is a common maintenance requirement for a reciprocating compressor?
• How is cooling capacity typically expressed in HVAC systems?
• How often should safety valves be inspected?
• Where is the scale trap typically located in a refrigeration system?
• The static setting of a thermostatic expansion valve is based on what measurement?
• If the high side float were to fill with liquid and sink, what would be the result?
• What happens to the volumetric efficiency of a compressor when the horsepower decreases?
• What main substance should be avoided in refrigerant oil?
• What is the typical effect of increased water flow in a cooling tower?
• How is the compression ratio defined in refrigeration terms?
• What is the formula for the perfect gas law?
• What is the primary objective of a low side float in a system?
• What is the process referred to as refrigerant reclaiming?
• What is the maximum amount of refrigerant allowed in a 120 lb. cylinder?
• What is the latent heat of fusion of water?
• A cooling tower is circulating 35,819 lb. of water per minute, what is the cooling capacity in tons?
• Why does the evaporator absorb heat from the air or brine?
• What is the lowest temperature that can be achieved by evaporating water into the atmosphere referred to as?
• What are the four main components of a refrigeration system?
• What is a result of overcharging a refrigeration system?
• What seal is not used on a refrigeration system?
• One ton of refrigeration equals?
• What happens to the temperature of the refrigerant in the compressor?
• Which of the following represents the formula for total force?
• What is the reason for subcooling the refrigerant?
• What precaution is used for safety from leakage in a liquid level sight glass?
• What does one calorie represent in terms of heat measurement?
• What is the latent heat of fusion for water?
• A refrigerant cylinder has a 125 lb. capacity. How many pounds can be stored in it?
• If condenser water has a pH of 10, how would this be classified?
• Describe the operation of a synchronous motor?
• What is the position of the suction and discharge valves during the re-expansion portion of the compression cycle?
• How many pounds of refrigerant can you put in a 3000 lb receiver?
• What do the terms friction head, velocity head, and pressure head collectively describe?
• What term describes the amount of heat energy removed per unit of time in refrigeration?
• What is the main reason for insulating the suction piping of a refrigeration system?
• Where is the oil trap usually located in a refrigeration system?
• What does a low side float prevent in a refrigeration system?
• In refrigeration systems, what is the primary purpose of a condenser?
• Which formula is used to determine tower water cycles?
• If a reciprocating compressor's discharge line is cool, what could this indicate?
• What is the primary function of the condenser in a refrigeration system?
• The flow rate of which fluid is crucial in determining a system's cooling capacity?
• The counterflow principle is a key feature of which type of condenser?
• What is the primary function of a condenser in a refrigeration system?
• What is the primary function of a refrigeration compressor?
• What describes the relationship between the actual performance of a compressor and its calculated performance?
• To achieve optimal system performance, monitoring what value along with cooling load is necessary?
• Which valve type is known for having the least resistance to flow?
• What typically causes an expansion valve to frost?
• What determines the low side pressure in a refrigeration system?
• What is the primary function of the expansion valve in a refrigeration system?
• What is true regarding the compression ratio of a reciprocating compressor?
• Which of the following could potentially cause a noisy compressor?
• If the power is removed from a solenoid valve and it opens, what type of valve is it?
• What is the formula for Total Dynamic Head (TDH)?
• When calculating tons of cooling, what is the divisor typically used?
• What is a notable advantage of a cascade refrigeration system?
• How is "free air" defined in refrigeration terms?
• What condition can cause high head pressure in a refrigeration system?
• What is the correct pitch for a 10 foot refrigeration line?
• What is the metric unit of heat measurement?
• What would occur in a lithium bromide absorption system if the cooling tower temperature dropped from 85 degrees F to 78 degrees F?
• Which condition is likely to cause high discharge pressure in a refrigeration system?
• What increase in condenser temperature could indicate scale formation?
• What two values are necessary to calculate the amount of refrigeration required?
• Which temperature scale is referred to as the absolute Celsius scale?
• What is the primary function of an evaporator in a refrigeration system?
• What is the main component used for heat transfer in a refrigeration cycle?
• What is the lowest recommended temperature for utilizing calcium chloride brine?
• Which factor would have the least effect on the capacity of a water cooled condenser?
• In a reciprocating compressor, what does the term swept volume refer to?
• Which component helps in protecting a pump from thermal shock?
• Which component in a refrigeration system works primarily to increase the pressure of the refrigerant?
• When suction pressure increases, how does this affect compressor capacity?
• Where is oiling required on a centrifugal refrigeration system?
• What is the purpose of wear rings on a centrifugal pump?
• What happens to the load when evaporator pressure goes down?
• What is refrigerant R-718?
• Which of the following would not cause a noisy compressor?
• Which type of compressor uses a damper to control capacity?
• The absolute Celsius scale is referred to by which temperature scale?
• What is the main purpose of an oil pump in a semi-hermetic compressor?
• What factor is crucial to consider regarding heat transfer efficiency in any heating and cooling system?
• What is required before starting newly installed refrigeration equipment?
• As the specific gravity of calcium chloride increases, what is the expected effect on the freeze point?
• As the condensing temperature of a centrifugal system decreases, what happens to the power required by the compressor?
• What is the primary function of a refrigeration compressor?
• What could cause oil foaming in a compressor crankcase?
• What is the characteristic of discharge gas from the compressor in a wet-compression refrigeration system?
• In a carbon dioxide system, what type of oil system is usually used for vertical compressors?
• Which refrigerant is commonly used for low-temperature applications?
• Thermostatic expansion valves are typically rated in which measurement units?
• What is a common indicator of a refrigerant overcharge in a cooling system?
• Which measurement describes the lowest temperature at which oil will flow?
• What term describes the volume occupied by a refrigerant under specified conditions of pressure and temperature?
• What is the role of a metering device in a refrigeration system?
• If a cooling tower has a pH of 7.8, how would it be classified?
• What should cooling tower water pH be maintained at?
• What does it indicate when a refrigerant is described as anhydrous?
• The capacity of an evaporative condenser primarily depends on which factor?
• What is the function of a dual control device in a single acting reciprocating compressor?
• In a system using an automatic expansion valve, where is constant pressure maintained?
• What is the role of the expansion device in a refrigeration system?
• What is the primary basis for rating a thermostatic expansion valve?
• Which of the following is essential to maintain optimal refrigerant flow through the system?
• What term describes the quantity of energy absorbed by a unit mass of refrigerant in the evaporator?
• What condition could prevent a system from responding to an expansion valve adjustment?
• What is the primary purpose of a stuffing box seal in refrigeration systems?
• What does the term “volumetric efficiency” in refrigeration typically refer to?
• Refrigerant recycling involves what primary action?
• In Fahrenheit, what is the equivalent of -15 degrees Celsius?
• If you had a flooded evaporator, which type of metering device would you use?
• How is "flash point" different from "fire point"?
• How is Boyle's Law expressed mathematically?
• What term describes the volume of a refrigerant under a specific pressure and temperature?
• What does the term 'BTU' stand for in refrigeration?
• Which type of compressor can be operated with a steam turbine as its prime mover?
• How much total force is exerted on a two-inch piston with a cylinder pressure of 130 psi?
• What happens to the freezing point if the specific gravity of calcium chloride brine is increased from 1.29 to 1.30?
• What determines the low side pressure in a refrigeration system?
• What are the four main steps of a mechanical refrigeration system?
• What type of heat increases the temperature of a refrigerant without changing its state?
• What is an effective way to ensure the reliability of a refrigeration system's performance?
• If water is leaving an efficiently operating induced draft cooling tower, what is the temperature of the water?
• Which of the following is a key factor in maintaining refrigerant efficiency?
• What effect does high ambient temperature have on a refrigeration system?
• When is it recommended to install oil traps in refrigeration lines during installation?
• When a compressor is turned on, which motor winding is energized?
• In refrigeration systems, reducing the pressure in the evaporator leads to which effect on the cooling process?
• What is the total force on a 4" piston with a cylinder pressure of 100 psig?
• What is the primary function of the compressor in a refrigeration system?
• In an absorption refrigeration system, where does the refrigerant typically release the latent heat of compression?
• What occurs to suction pressure as capacity decreases in a reciprocating compressor?
• How is one British Thermal Unit (BTU) defined?
• How many Btu/hr are required to produce one ton of cooling?
• What is the primary purpose of a refrigerant in HVAC systems?
• Which type of motor is typically used on condenser and evaporator motors?
• What is the maximum amount of refrigerant allowed in a 3000 lb receiver?
• What does the pour point of oil indicate?
• Which type of compressor commonly utilizes a slide valve for capacity control?
• In a synchronous motor, as the DC amperage increases, what happens to the AC amperage?
• What is the process of converting 373 degrees Rankine to Kelvin?
• What is the purpose of the evaporator in a refrigeration cycle?
• What is the capacity of a 100 ton refrigeration unit in BTU's per minute?
• In a cooling system, what does the presence of frost on the evaporator suggest?
• Which statement about lithium bromide used in absorption systems is false?
• Which type of valve can seal at higher pressures?
• What is the name given to the temperature at which vapor at 100% humidity starts to condense into a liquid?
• What is the function of the condenser in a refrigeration cycle?
• The specific gravity of brine is primarily measured to determine which component?
• Why is pre-cooling air important in an ice making plant?
• In a reciprocating compressor, how do the unloaders unload the pistons?
• What is the maximum fill allowed for industrial refrigeration condensers and receivers?
• How many BTUs must be removed to lower the temperature of 2000 lbs of ice from 32 degrees F to 29 degrees F?
• Which direction would a normally open valve move if there were a small leak in the pneumatic line?
• What is the conversion of 5 degrees Fahrenheit to degrees Rankine?
• As the specific gravity of calcium chloride increases, what happens to its density?