GCAP Book Practice Test

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• What could potentially occur if ammonia in a vessel is subjected to heating without room for expansion?
• What is the basis for the required energy to convert liquid water to steam at its boiling point?
• What is the general approach to emergency response when ammonia exposure occurs?
• What does the compressor control in terms of refrigeration?
• During hot gas defrost, which state change occurs in the evaporator?
• Which component is responsible for the conversion of refrigerant phases in a refrigeration system?
• What type of refrigerant state is usually desired before it enters the compressor?
• If an evaporator is rated at 120,000 BTU/HR, what size must the condenser be?
• Why can oil gather in the evaporator at the lowest point in an ammonia system?
• What does temperature measure in relation to heat?
• In refrigeration, a saturated state indicates what?
• How is the tonnage rating calculated for an air conditioner that removes 48,000 BTUs in one hour?
• What type of heat transfer is exemplified when discussing how a lamp gives off heat?
• Does mixing oil with ammonia increase the risk of fire if released in the presence of an ignition source?
• How is a compressor classified in a refrigeration system?
• Is ammonia listed on the EPA toxic chemical list?
• What is the permissible exposure limit (PEL) for ammonia set by federal OSHA?
• Specific heat (Cp) refers to what?
• What is the main function of the evaporator in a refrigeration system?
• What is a potential drawback of using hot gas defrost cycles?
• What may happen if a pipe or vessel full of liquid refrigerant is isolated?
• Heat flowing through a copper bar with one end in a fire is an example of which type of heat transfer?
• Which type of compressor is not classified as a positive displacement compressor?
• True or False: Semi-hermetic pumps have an external motor connected to the armature with a mechanical shaft seal.
• What is a back pressure regulator?
• What type of compressor relies on centrifugal force to move gas?
• What is the practical maximum compression ratio for a reciprocating compressor?
• What is the goal of implementing a hot gas defrost system?
• What role does the expansion device play in a refrigeration system?
• What is the primary risk associated with ammonia in industrial settings?
• Latent heat is described as?
• What mechanism activates the capacity control of the compressor?
• What must occur across a metering valve for it to be classified as an actual expansion valve?
• What is one disadvantage of ammonia as a refrigerant?
• Which of the following is true about latent heat?
• What does the number 1005 on a green diamond indicate about a transportation vehicle's contents?
• What happens to the pressures within the system during hot gas defrost?
• Which system component is responsible for regulating the flow of hot gas during the defrost cycle?
• How long do most MSDS sheets recommend flushing the eyes with water when exposed to liquid ammonia?
• What effect does overfeeding liquid to a DX evaporator have?
• What type of injury can result from a liquid ammonia exposure?
• What characteristic of ammonia affects its miscibility with oil?
• What is a main cause of liquid slugging in a system?
• Which of the following increases during the hot gas defrost process?
• Can the wet bulb temperature affect the efficiency of an evaporative cooled condenser?
• According to OSHA regulations, should an operator wear contact lenses when dealing with ammonia refrigerant?
• What is the function of safety springs in reciprocating compressors?
• In which section of a refrigeration system is the worst place to have a leak?
• What component supplies saturated liquid refrigerant to the bottom of the evaporator in flooded systems?
• Which temperature requires approximately 561 BTUs for the transformation of 1 pound of ammonia?
• What is the primary function of the condenser in a refrigeration system?
• In a DX or dry expansion evaporator, in what condition should the refrigerant leave?
• At what percentage does the lower explosive limit (LEL) for ammonia start?
• What component is primarily responsible for controlling the overall highside pressure in a mechanical refrigeration system?
• What is the method used in hot gas defrosting?
• How much heat must be absorbed to convert 1 pound of saturated NH3 liquid to saturated NH3 gas?
• Where should noncondensibles be manually purged from in a refrigeration system?
• For each pound of water evaporated, how many BTUs does an evaporative condenser reject?
• How many BTUs are required to convert 1 pound of saturated liquid ammonia to saturated gas?
• In a baffled shell and tube heat exchanger, where does ammonia refrigerant flow?
• What action should be taken immediately if a compressor shows signs of hydraulic pounding?
• Which of the following is a style of condenser?
• Which type of evaporator has the least amount of fan space per inch for its operational duties?
• When should oil be tracked in a refrigeration system?
• What is the purpose of a surge drum in a flooded refrigeration system?
• Copper tubing is never used with which refrigerant?
• What does tonnage refer to in HVAC systems?
• What is a common symptom of low refrigerant levels in a system?
• What is the primary effect of high head pressure on a compressor system?
• What is the Celsius equivalent of 56°F?
• Which two tools are primarily used for detecting small leaks of ammonia?
• If the liquid drain from the condenser is at 82°F and head pressure is 182 psi G, what does this indicate?
• In a recirculation system, where is it important to maintain constant pump pressure?
• What is the energy requirement for a total phase change of liquid water to steam at 212°F?
• True or False: Cavitation is beneficial for liquid pumps.
• What is the consequence of exposure to ammonia above the permissible exposure limit?
• Are oil and liquid ammonia miscible?
• Changing the pressure on refrigerant will alter what property?
• What is the primary function of the fluid in the flooded system of a shell and tube chiller?
• What are the three types of positive displacement compressors used in the industry?
• What type of refrigeration systems typically employ hot gas defrost methods?
• If the power element of a thermostatic expansion valve loses its charge, what is the likely result?
• What is sensible heat defined as?
• How many groups of halocarbons exist?
• How much will the PSIG pressure rise for every 1°F of heat exposure in an ammonia liquid line with liquid trapped?
• Is it safe to proceed through an invisible cloud of ammonia?
• When using a screw compressor with an oil separator, how should the heater operate?
• What is the IDLH (Immediately Dangerous to Life or Health) level for ammonia according to OSHA?
• What effect does air noncondensible gas have on suction pressure in an ammonia system?
• What defines a two-stage compression system?
• What is the practical maximum compression ratio for a rotary vane compressor?
• Where should an auto purger be piped from on the condenser?
• In a two-stage ammonia refrigeration system, which compressor is generally started first?
• What should you avoid when dealing with liquid ammonia in atmospheric conditions?
• What should be done with a high-pressure cut out switch?
• If an ammonia receiver can hold 1000 pounds of liquid at 90°F, what is the mass capacity for this receiver?
• How does warmer ambient temperature typically affect the efficiency of a refrigeration system?
• If a low temperature ammonia booster compressor's discharge temperature drops suddenly from 120°F to 80°F, what is indicated?
• What type of heat transfer is demonstrated by the warmth of sunlight?
• In a DX or dry expansion coil evaporator, what state should the refrigerant leave?
• What color is typically associated with the hazard diamond that indicates a gas like ammonia?
• How does hot gas defrost affect the refrigerant flow in the evaporator?
• What conditions are associated with high head pressure in a refrigeration system?
• Which chemical property of ammonia makes it important to monitor for potential hazards?
• Which method is typically used to ensure effective oil separation in oil separators?
• What kind of energy change occurs when changing 1 pound of liquid ammonia to gas?
• In what form do evaporators typically exist in refrigeration applications?
• What is the main operational hazard associated with running a compressor that takes liquid ammonia?
• Which compressor is commonly started first in a two-stage system?
• What is the ideal outcome of a well-maintained refrigeration system?
• What is the percentage range at which the upper explosive limit (UEL) for ammonia ends?
• What role does the expansion valve play in the refrigeration cycle?
• If refrigerant pressure increases, what happens to the boiling point?
• If using a TXV, which type of evaporator is typically employed?
• How are blades forced outward in a rotary vein compressor?
• What is a common cause of liquid slop over in an ammonia refrigeration system?
• What is one style of oil pulling for compressors?
• What happens to the oil in the compressor when it is mixed with ammonia?
• For which condition is the pressure/temperature relationship for ammonia valid?
• What is the primary action taken during hot gas defrost in a refrigeration system?
• What condition describes a refrigerant that is at its saturation point?
• What is the concentration of ammonia that is equivalent to 10,000 parts per million?
• What is the heat exchange required to melt 1 pound of ice to water at 32°F?
• Does ammonia cause cancer?
• What are two other critical components of a refrigeration system aside from the compressor, condenser, expansion device, and evaporator?
• Is it safe to apply direct liquid water to liquid ammonia hazards?
• What effect does a small percentage of ammonia have when mixed with oil under reduced pressure?
• Which of the following identifies the three types of feeds in refrigeration systems?
• Which component is directly involved in providing the high-pressure gas during hot gas defrost?
• What qualifies as a reportable release of NH3 in a 24-hour period?
• If a refrigerant is superheated, what does it imply?
• What is the volume of a cold storage room measuring 150 feet long by 80 feet wide by 35 feet high?
• What is fluid friction or vapor resistance in the context of refrigeration systems?
• What is the fuel range for pure ammonia in terms of its concentration in air?
• Which component is responsible for managing the flow of refrigerant in the system?
• What must happen to a gas before a condenser converts it to a liquid?
• Can you knock down an ammonia vapor cloud using water under atmospheric conditions?
• How many BTUs are involved in converting 1 pound of liquid water at 212°F to steam?
• If you touch a hot ceramic coffee mug with your hands, this exemplifies which type of heat transfer?
• What condition is necessary for optimal operation of the evaporator?
• Is it true that an operator must wear an ammonia-rated respirator if they are in an atmosphere containing ammonia?
• What is one important check an operator must perform before starting up a compressor?
• What type of fan pushes air through coils in a refrigeration system?
• In what way do evaporators function within refrigeration systems?
• What is the function of the King valve in a refrigeration system?
• What is commonly expected if the discharge temperature of a compressor remains constant?
• What is the practical maximum compression ratio for a rotary screw compressor?
• Is 10 PSIG a greater pressure compared to 10 PSIA?
• What is the first step taken before initiating a hot gas defrost cycle?
• What is a characteristic feature of a blast freezer evaporator?
• What is the primary function of the compressor in a refrigeration system?
• What is the volume of a room with dimensions of 10 feet in length, 14 feet in width, and 20 feet in height?
• In hot gas defrosting, which phase change in the refrigerant is primarily responsible for removing frost?
• When refrigerant is saturated, what does that indicate?
• If one increases superheat on the inlet of the compressor, what would most likely occur?
• Where are BTUs from the product of the heat of compression rejected?
• What should an operator do if a compressor takes a slug of liquid ammonia and begins hydraulically pounding?
• What is the minimum difference in oil pressure required for a reciprocating compressor above suction pressure?
• Typically, how much superheat is expected at the outlet of an evaporator under normal load conditions using the overfeed design?
• Which of the following is a best practice when working in environments with ammonia exposure?
• What energy exchange occurs when converting 1 pound of saturated liquid ammonia to saturated gas?
• Where should manual purging of a condenser occur when it is turned off?
• What does it mean if a substance is experiencing sensible heat transfer?
• Which system style utilizes a liquid pump to transfer liquid to evaporators?
• What does the effectiveness of hot gas defrost depend on?
• What is the pH level of ammonia?
• Rotary veins are typically limited to which type of application in ammonia refrigeration?
• What is the fire diamond rating for pure ammonia regarding health?
• Is a 5,000 ppm concentration of ammonia considered deadly?
• If the suction pressure of a refrigerant system is dropped, which of the following would not occur?
• What is the key difference between a unit cooler and a blast freezer?
• What is the typical gas tax/flash/gas percentage in operating an ammonia refrigeration system with the evaporator at 10°F and the condenser at 85°F?
• What effect does the presence of non-condensables have on a refrigeration system?
• What type of compressor is not suitable for industrial ammonia refrigeration systems?
• Zerotropic and azeotropic are types of refrigerants that are considered what?
• What type of burn is NOT associated with liquid ammonia exposure?
• Where should superheated gases exist in all refrigeration systems?
• What occurs during a hot gas defrost cycle?
• An increase of superheat on the bulb of a TXV causes the valve to do what?
• What does a relief valve do in a refrigeration system?
• When placing a solenoid valve in automatic mode, what must be done according to manufacturer guidelines?
• What effect does heat removal in the condenser have on refrigerant?
• What may happen to a drive motor when the room temperature rises to +30°F and is then pulled back down to -10°F?
• What does specific heat (Cp) measure in a substance?
• The metering or expansion valve controls what aspect of the refrigerant flow?
• What is the intended effect of using hot gas for defrosting?
• What should an operating engineer do in the event of liquid slugging?
• How do evaporative condensers derive their heat rejection capability?
• Which condition indicates evaporator temperature in the engine room?
• What is the most likely result of thermal shock in an evaporator?
• What state is the ammonia in a refrigerant line at 80°F and 120 psi G?
• How much does hydrostatic expansion increase pressure per degree Fahrenheit heat exposure for ammonia?
• What is 100°C equivalent to in Fahrenheit?
• How can the capacity of an ammonia receiver be affected by temperature?
• What does the conversion of saturated NH3 liquid to gas primarily indicate in the refrigeration cycle?
• If liquid ammonia comes into contact with the eyes, what is the usual result?
• Compressors in refrigeration systems are primarily sized based on which requirement?
• How does fluid friction primarily affect the refrigeration process?
• Which method is typically used to check for leaks in an ammonia piping system?
• What pressure scale is necessary to calculate a compression ratio?
• What is the direction of flow through every condenser?
• How are energy changes represented when melting ice into water at 32°F?
• From where can oil be drained in an ammonia system?
• What is the process for separating oil in an impingement style oil separator?
• What is the approximate amount of BTUs needed to melt or freeze 1 pound of ice/water at 32°F?
• When a refrigerant is said to be subcooled, it means it is at a temperature below its saturation point and is in which state?
• Approximately how many BTUs are necessary to turn 1 pound of water at 212°F into steam at the same temperature?
• Which of the following is NOT one of the four primary types of injury caused by exposure to liquid ammonia?
• What is the fire diamond rating for pure ammonia regarding fire?
• What is the effect of allowing a room's temperature to rise significantly on a refrigeration system's performance?
• Which compressor type may incorporate safety springs for liquid management?
• Which statement is true regarding the properties of ammonia?
• What might indicate that a refrigeration compressor has failed?
• What is the phase change that occurs in a condenser when it removes heat from refrigerant?