Download Refrigeration System Fundamentals and more Exams Nursing in PDF only on Docsity! 1 | P a g e FDNY Z51 REFRIGERATION EXAM 2 2024-2025 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQUENTLY TESTED QUESTIONS AND SOLUTIONS |ALREADY GRADED A+|BRAND NEW!!|GUARANTEED PASS|LATEST UPDATE A motor winding is touching the inside of the motor housing. This could result in: Shock may occur to personnel An engineer suspects a short of the motor winding have caused the motor to trip on overload. The engineer should use what instrument to check the motor: Ohmmeter An engineer would expect a relief valve to start function at a pressure: Design pressure How many BTU's are removed in a 30 ton system? 360,000 BTU's per hour An engineer is requested to replace a gauge on the high side of the system. The pressure graduation rate should be: At least 1.2 times the design pressure An automatic expansion valve maintains a constant: Evaporator pressure During inspection of a facility, you notice that there has been failure to maintain water treatment of the condenser water. The first evidence of a problem would be: An increase in compressor head pressure 2 | P a g e If the air lowers below the fans in an induced draft cooling tower become clogged, the result would be? Higher return water temperature close and You have a cold front and there is a sudden drop in temperature. The thermostat will cause the solenoid valve to: Close and pump the compressor down and shut down on low pressure Cross connections and standpipe rises must be painted: Red Under certain circumstances, is it ok to chain an exit door? No, it is never okay How would you calibrate a thermometer? Place the thermometer in a cup of ice water What device automatically controls the speed of a steam turbine? Governor valve What happens when a steam turbine reaches critical speed? Turbine will vibrate violently Superheat increasing gradually over a week, what could be the cause? Leak in system What would happen if a TEV's spring were to break? Flood the evaporator Why are flare fittings not used in 3/4" diameter copper piping? Soldered or brazed joints are better In a refrigeration system with a high side float, frost on the suction line indicates? There is an excess of refrigerant in the system What color is the top of a TEV in an R22 system? Green Regardless of the safety classification, in the event of refrigerant leaks an RMO should be aware of? Asphyxiation What refrigerant is most often used in the bulb of a thermostatic expansion valve? The same refrigerant that is in the system 5 | P a g e The suction pressure of a reciprocating compressor is 65 PSIG. The discharge pressure of this compressor is 120 PSIG. The atmospheric is 14.7 PSI. The compression ratio for the given condition is closest to: 1.69 A superheated vapor is: Dry vapor above the saturation temperature A refrigerant engineer verifies that a condenser water pump is cavitating. Of the following, the most likely cause for this condition is: A faulty cooling tower water level controller A centrifugal water pump is known as a lift pump when the: The water supply to the pump suction inlet is below the pump level A TXV is used to maintain constant: Evaporator superheat The chilled water supply to the building is 55 deg F. If the chiller is being used for human comfort, should you be concerned about this, and why? Yes, this temp is too high for human comfort purposes The packing gland of a centrifugal pump serves to: The drip part of the packing gland gives evidence that there is water in the pump Capacity control of reciprocating hermetic compressor is typically achieved through: Operation of the hot gas bypass valve The most important reason to sub-cool the refrigerant in the condenser is to ensure that: A pure liquid refrigerant will enter the metering device A refrigeration engineer is logging readings from a reciprocating system. Compressor discharge temperature have dropped significantly and the suction line pressure is high. Which of the following that may be causing this set of condition? An expansion valve that is open too wide A low side float valve is used to maintain: The level of the refrigerant in the evaporator Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity? A1 6 | P a g e When an expansion valve is operating properly, at the end of the evaporator will contain: Only superheated vapor What information is not contained in a Material Safety Data Sheet? Cost of the material In a steam turbine, what is the function of the Kingsbury thrust bearing? Maintain axial positioning of the rotor shaft A centrifugal water pump is considered to the fully primed when? The pump is full of liquid Copper tubing refrigerant lines must be installed for a new system. It is a well known service practice that tubing collapses at bends that must be made, the refrigerant engineer should use? Level type tubing bender A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn parts are not causing the knocking, what probably the cause? Slugging of the liquid refrigerant In order for a refrigerant to become superheated, it must be heated in a section of the low side refrigerant line: Where no liquid refrigerant is present All liquid has been recovered from a system to be overhauled, the system: Should not be opened until all vapor has been recovered When a refrigerant engineer uses a portable compressor recovery unit to remove vapor refrigerant from a refrigeration system the removal rate of the refrigerant will gradually slow down because? The compressor efficiency is decreasing You are the engineer running a 2000-ton (steam driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. During the course of making your rounds, you check the 9 cell cooling tower on the roof. You note the water level in all of the cooling tower cells is very low. Which one of the following immediate actions would take? Add additional make up water to the cooling tower A rooftop water cooling tower is connected to a water pump in the building basement with a 12 inch diameter pipe. With the pipe turned off, a pressure gauge at the pumps inlet show a pressure of 140 PSIG the height of the water column, in feet, would be closest to: 323 What device protects the steam turbine from excessive speed? 7 | P a g e Governor assembly A refrigeration compressor has failed to turn on. The refrigeration engineer on duty verifies that the electrical circuit to the motor, including all switches and circuit breakers, is complete according to recommended service practice, the next item to be checked would likely be the: Temperature and pressure controls Refrigerants are characterized by their physical properties included flashpoint, refrigeration effect, and others. Of the refrigerants in commercial and industrial, the one with the highest latent heat and refrigerant effect is: Ammonia Of what characteristics is ASHRAE refrigerant safety group classification system: Flammability and toxicity Of the following, an example of an in line refrigerant cleaning system that may be used with a centrifugal compressor containing R-123 refrigerant is: Recycling Information about the physical and chemical properties of a hazardous material can be found in: Material Safety Data Sheet What is the function of the turbine auxiliary oil pump? Establish oil pressure during turbine start up The rupture disc for a low pressure centrifugal refrigeration machine is normally located on the: Compressor suction What is the primary reason ribbed metal piping is used for electrical wires connected to the refrigeration system shown below? It allows for flexibility and accounts for vibrations A multi cylinder reciprocating compressor uses cylinder unloaders to regulate capacity, what would not occur if some of the unloaders fail to operate when needed? The chill water temperature will increase As shown in the picture below, the suction gauge of a condenser water pump reads 55 PSI. The pipe supplying the pump is 75 feet long and 12 inches in diameter. Approximately, how many gallons of water do you expect to obtain if the pipe is drained completely? 440 A water chiller system uses refrigerant R-123. A leak in the evaporator shell may result in: A higher than normal high side pressure 10 | P a g e Sudden drop in the crankcase pressure Assume that an engineer is able to observe refrigerant water and oil together. The fluids would settle in the container from top to bottom as follows: Oil, water, refrigerant What is the function of the vacuum breaker in the steam turbine? To achieve a faster cost down cycle An equalizer line on a TXV is used to: Compensate for the pressure drop across the evaporator coil If R-134 accidentally touches a refrigerant engineer's skin, what first aid should be applied from the MSDS? Promptly flush the skin with water until all chemical is removed In a multi-stage centrifugal compressor, each stage: Is identical in volume to the other stages A refrigeration engineer notices excessive cycling of the temperature control for a reciprocating compressor refrigeration unit. The crankcase temperature is high, the compressor discharge temperature is low, the suction line temperature is high. Of the following, the one that may cause this set of condition is? Faulty compressor valves On an operating centrifugal compressor refrigerant unit, the refrigeration engineer notices that the compressor is short cycling. The unit is using a low side float valve as a metering device. Of the following requirements, this would indicate that: The system is undercharged with refrigerant The vessel depicted below may used in connection with Refrigerant recovery A refrigeration system uses jet ejector to raise settled oil mixed with refrigerant to the oil pump. If a restriction in the refrigerant flow to the jet ejector develops: There may be insufficient head to lift the oil An indirect, low temperature refrigerant system frequently uses glycol, instead of salt brine as the intermediate cooling medium. An advantage of this choice is: The elimination of corrosion In relation to the suction pressure of a compressor, the reading on the oil pressure guage should read in the range, closer to: 11 | P a g e 15 to 30 PSI higher Non-condensable gases like air, oil vapor, or nitrogen travel through a refrigerant system with the refrigerant they usually accumulate in the: Condenser The advantage of forced draft cooling tower over natural draft cooling towers is: Smaller tower size The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system when it is in operation only when: Relieved by another licensed refrigeration engineer A system controlled by a TXV shows high discharge pressure and high normal subcooling. The cause is most probably a: Refrigerant overcharge Which of the following is a correct statement? 2.5 gallons of water weighs 20.8 pounds Liquid level gauge glasses (except the bull's eye) are generally equipped with: Automatic shut off valves only Copper and aluminum are frequently used for condenser tubes in refrigeration system. These metals are used because of their: High heat transfer coefficient Assume that a refrigeration engineer has a choice of four valves to select from. Which of the following is the most effective type of valve to control pressure? Plug valve Where must the Material Safety Data Sheets be located? Where available to all employees The oil collected in an oil separator is generally: Returned to the compressor What is the function of gland steam? Seal the turbine rotor carbon rings Regarding the functioning of steam turbine, how is the water level controlled in the surface condenser hot well? Operation of the recirculation and overboard valves 12 | P a g e The cause of the starved evaporator might be: Low refrigerant charge A refrigeration engineer is running two centrifugal condenser water pumps in parallel. One of the pumps is at it's maximum pumping rate. If by mistake, the refrigeration engineer throttles back on the discharge valve of the other pump, the most likely effect will be: A reduction on the total flow rate to the condenser The total amount of heat to be removed from the refrigerant in a condenser equals the heat picked up in the: Evaporator plus the heat of compression The amount of electrical power used to operate a solenoid valve or a motor is measured in: Volts Of the following, the most common metering device used today in reciprocating commerical refrigeration system under three tons capacity is: TEV The purpose of wear rings in a centrifugal pump is to: Prevent wearing of the pump housing and impeller You are the engineer running a 2000-ton (steam driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. While making rounds, you notice that the condenser water coming back down from the 9-cell cooling tower on the roof is at a temperature of 90F. You want to make an adjustment to bring the temperature of the condenser water down to 85F. Which one of the following immediate actions would you take? Increase the speed of the cooling tower fans A water chiller is equipped with a reciprocating compressor, a thermostatic expansion valve, and an air cooled condenser. A restriction in the refrigerant liquid line would result in: High suction superheat A solenoid valve is used to allow a reciprocating refrigeration machine to adapt to the load on the system. The opening of the solenoid valve is caused by: An electrical current creating a magnetic field The process by which refrigerant is extracted and cleaned for reuse without requirements for reclamation is called: Recycling A centrifugal compressor is in operation with suction pressure is 3 PSIG and the discharge is 10 PSIG. What is the atmospheric pressure is 14.7 which is the ratio closets to: 15 | P a g e Which of the following will connect to the middle port on a gauge manifold? Vacuum pump The most important reason for installing a muffler in reciprocating refrigerant machine is? To contain the compressor pulsation noise Of the following, the statement that most accurately characterizes a hermetic compressor is that it: Will have both the compressor and motor enclosed is gas tight housing In the picture, the valve is in what position The valve is cracked open What is the order of components on the liquid line of reciprocating system from the condenser? King valve, filter drier, solenoid valve, sight glass A high side float valve is used to maintain: Constant level of refrigerant in the evaporator Picture of a pump Ninety degrees reducing elbow, pump suction, pump casing, pump discharge, check valve Picture of a compressor Oil charging port allows for the addition and removal of oil from the compressor A facility has failed to maintain water treatment to a refrigerant system Increase in the condenser pressure Which of these compressors is not a positive displacement type compressor? Centrifugal Where is emergency power not required according to code? Data centers What is the most widely used regulation book by operating engineers? EPA (Environmental Protection Agency) What type of refrigerant do you need FDNY approval for? Propane Centrifugal pressure is determined by? Speed of motor A single phase 208 VAC circuit has 2 hot wires, the third is the: 16 | P a g e Ground Liquid refrigerant that has passed through a metering device is a: Low, pressure saturated liquid With a 75 degree dry bulb and a 73 degree wet bulb, the relative humidity is: Very high After recovering liquid refrigerant from a centrifugal chiller, the next step is to: Recover vapor Where is the muffler located? Between the compressor and condenser What is not required to be serviced annually? Compressors What is the advantage of a shell and tube condenser as opposed to a shell and coil condenser? Better heat transfer Fusible plugs on a condenser The melting point is marked on it How much extra refrigerant can be stored in a machine room? 330 lbs What is used on an outside pipe to prevent it from freezing? A resistor Of the following, centrifugal chillers are best characterized as? High tonnage, low pressure machines As an engineer, you notice pressure drops across the evaporator. You check and notice the external equalizer line is disconnected. What will occur in the evaporator? Evaporator will flood When entering Phase II fireman's service, what statement is correct? The elevator operator is the only person that could control the elevator A FDNY permit is required to conduct hot works for? Use of oxygen and flammable gas FDNY is most concerned with which ASHRAE refrigerant classification? 17 | P a g e A3 How long must a fire alarm log book be kept? 6 months What is the minimum requirement an engineer needs to log readings? Once per shift You are the only engineer on duty with a machine running. A vice president tells you to shovel snow. What should you do? Do not leave the building How often must you do emergency power testing? Monthly What is the responsibility of a B29 COF holder? Inspect the battery system Why is a refrigerant gauge called a compound gauge? It reads positive pressure and vacuum Which of the following does not require flame resistant treatment? Artwork in a museum An engineer observes a gauge that saturation pressure of a refrigerant. If chilled water is circulated as the cooling medium this reading best be used to estimate the: Temperature of chilled water being pumped to the spaces being cooled Regardless of the ASHRAE refrigerant classification in use, in the event of a refrigerant escape the engineer should be aware of: Asphyxiation What type of refrigerant is found inside the machines gauges? Same type of refrigerant inside the machines If resistance is cut in half, what happens to the power factor? Increases by a factor of two What are pre hot works procedures preformed prior to hot works? Check area once a day leading up to hot works A chilled water system that has an air cooled condensing unit on a roof during cold weather, has what type of protection? 20 | P a g e Vent refrigerant and nitrogen to open air What is the device used to measure the speed of a turbine? Tachometer The condenser pump is on the first floor and not running. The pressure gauge shows 55 psi. There is 15 feet for each floor. What floor is the cooling tower on? 8th Floor There is 7.48 gallons per cubic foot. How many gallons of water are in a pipe 8 feet in diameter and 10 feet long? 3758 A technician has been asked to estimate the cost of operating a 5 horse power motor. Because the plant is build by energy consumed as kilowatt-hours, the technician will have to calculate the conversion. The equivalent in energy of a 5 horse power motor operating for 9 hours in kilowatt-hours is closest to: 33.6 A standpipe system will be out of service for two days. How long should there be a fire watch? The entire time the standpipe is out of service A circuit breaker has a similar function as what: A fuse How do you start a centrifugal chiller? Start the chilled water pump, start the condenser water pump, check oil, start cooling tower, start compressor If a sprinkler system is offline for two days, how often do you need to inspect it until it is returned back to service? Continuously, 24 hours a day until system is restored The only refrigerant/temperature chart available to a refrigerant engineer lists the temprature in degrees Celsius. If the chart indicates a Celcius temperature of 5 degrees, the equivalent in Fahrenheit is 41 degrees In the picture below, what does the equipment detect? Refrigerant leaks In a building with multi-zone standpipe system, how does each zone get supplied with water? Each zone will have its own automatic water supply Which service valve should be installed to isolate a dual pressure relief valve while keeping system in service? 21 | P a g e Three way valve When will the BTU's exchanged be the greatest? Low evaporator temperature, high condenser temperature You find that the check valve on a centrifugal pump is leaking. When would the most damage be caused to the pump? On startup of the pump The efficiency of the refrigerant cycle is affected by the operation of the condenser. of the following. a more efficient centrifugal compressor operation results from: Lowering the condensing pressure The heat removed from the refrigerant in a condenser is: Sensible and latent heat The refrigerant unit that you have been assigned to is being taken out of service for a major repair. you have been assigned to withdraw refrigerant for storage in suitable containers. according to the new York city fire code, you must ensure that the containers: Are approved by the US department of transportation Which of the following best describes how the cylinder unloader work? Keep in the suction valve opened while the compressor is in the return stroke In most semi hermetic compressors, the suction vapor is used to: Cool the motor The amount of refrigerant that flows through the orifices of a economizer is determined by the: Difference between the high side and load side pressure The installation of an inline refrigerant cleaning system is advisable: To remove impurities from the system The type of refrigerant system that is least likely to leak refrigerant into the building space that are cooled The indirect system The suction pressure of a reciprocating compressor is 65PSIG. the discharge pressure of this compressor is 120PSIG. the atmospheric is 14.7 PSI. the compression ratio for the given condition is closet to: 1.69 A super heated vapor is a ? Dry vapor above the saturation temperature 22 | P a g e A refrigerant engineer verifies that a condenser water pump is cavitating. of the following the most likely cause for this condition is: A faulty cooling tower water level controller A centrifugal water pump is known as a lift pump when the: The water supply to the pump suction inlet is below the pump level A TXV is used to maintain constant: Evaporator superheat The chilled water supply to the building is 55F. if the chiller is being used for human comfort, should you be concerned about this , and why? Yes, this temperature is too high for human comfort purpose The packing gland of a centrifugal pump serves to: The drip part of the packing gland gives evidence that there is water in the pump Capacity control of a reciprocating hermetic compressor is typically achieved through Operation of the hot gas bypass valve The most important reason to sub-cool the refrigerant in the condenser is to ensure that: A pure liquid refrigerant will enter the metering device A refrigeration engineer is logging reading from a reciprocating system. compressor discharge temperature have dropped significantly and the suction line pressure is high. which of the following that may be causing this set of condition. An expansion valve that is open to wide A low side float valve is used to maintain: The level of the refrigerant in the evaporator Regarding fire safety, which ASHARE refrigerant safety classification indicates no flammability and lower the toxicity? A1 When an expansion valve is operating properly, at the end of the evaporator will contain: Only superheated vapor What information is not contained in a material safety data sheet-MSDS? Cost of material In a steam turbine, what is the function of the kingsbury thrust bearing 25 | P a g e Which of the following correctly describes the object in the picture below? Standpipe hose outlet to put out fires in cae of emergency Modern compressors usually seal the rotating shaft as it exits the compressor housing a spring loaded seal made of Metal or carbon The British Thermal Unit (BTU) is the measurement of heat of energy. if 10 BTU are transferred to 10 pounds of water, the water temperature increase will be closest to: 1F A reciprocating compressor cylinder has a 10 inch bore and 14 inches stroke. the volume of refrigerant, in a cubic inches, will be closer to: 1099 An electrically operated control requires 24 volts to operate. to change the available 110 volts to 24 volts Transformer In an indirect refrigerant system, of the following , the one that would not be used as a cooling medium for the building spaces being cooled is: R22 refrigerant On a steam turbine, what would cause the atmospheric valve to open? low vacuum in the surface condenser, leaking tubes in the surface condenser, dirty tubes n the surface condenser You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. making your rounds, you notice that condenser water pump #1 is making a lot of noise, the discharger gauge reading of the condenser water pump is fluctuating drastically, and motor of the condenser pump #1 is running very hot. which of the following actions would you take: Turn on pump #2 shut off pump #1, and trouble shot pump #1 Electric devices may be used to provide built in defrosting of refrigeration machine evaporator units. these devices are classified as Resistors The flash point of compressor lubricating oil: Should be higher than the compression temperature The primary way of achieving capacity control of a centrifugal compressor is by; Adjustment of the impeller inlet pre-rotation vanes 26 | P a g e Cooling tower water requires the addition of chemical additives in order to: Reduce the formation of scale and algae In the picture below describe the equipment's function? Remove non condensable from the condenser the viscosity of lubrication oil is described by a number. a low viscosity number describes oil that: Flows easily The most likely reason for a refrigeration engineer to use a psychrometer is to measure Relative humidity level of the atmosphere The most important reason to use at least two compressors in a cascade system is to: Avoid very high compression ratio for each compressor The suction service valve of a reciprocating compressor is front seated and the compressor runs until the low pressure cut-out shut the compressor off. when the machine is stopped, the refrigeration engineer notices that the suction pressure increase rapidly. the most probable cause of this pressure rise: Malfunction of a compressor valve Regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as possible? Keeps turbine blades wear to minimum According to the attached Material Safety Data Sheet (MSDS) R134 is a Clear, odorless liquid and vapor Under normal condition, the refrigerant enters the compressor as a: Low pressure superheated vapor and leaves as a high pressure vapor While operating an R-22 single acting compressor system, the refrigeration engineer noticed oil foaming in the crankcase. this condition most likely, would have been caused by a : Sudden drop in the crankcase pressure Assume that an engineer is able to observe refrigerant water and oil together. the fluids would settle in the container from top to bottom: Oil, water, refrigerant What is the function of the vacuum breaker in a steam turbine. To achieve a faster coast down cycle An equalizer line on a TXV is used to: 27 | P a g e Compensate for the pressure drop across the evaporator coil If R134 accidentally touches a refrigerant engineer's skin, what first aid should be applied from the MSDS? Promptly flush skin with water until all chemical is removed In a multi stage centrifugal compressor, each stage: Is identical in volume to the other stages A refrigeration engineer notices excessive cycling of the temperature control for a reciprocating compressor refrigeration unit. the crankcase temperature is high, the compressor discharge temperature low, the suction line temperature high. of the following the one that may causing this set condition. Faulty compressor valves On an operating centrifugal compressor refrigerant unit, the refrigeration engineer notices that the compressor is short cycling. the unit is using low side float valve as a metering device. of the following requirements this would indicate that: The system is undercharged with refrigerant The vessel depicted below may used in connection with Refrigerant recovery A refrigeration system uses jet ejector to raise settled oil mixed with refrigerant to the oil pump if a restriction in the refrigerant flow to the jet ejector develops: There may be insufficient head to lift the oil An indirect ow temperature refrigerant system frequently uses glycol , instead of salt brine, as the intermediate cooling medium. an advantage of this choice is: The elimination of corrosion In relation to the suction pressure of a compressor, the reading on the oil pressure gauge should read in the range, closer to: 15 to 30 PSI Higher Non- condensable gases like air, oil vapor, or nitrogen travel through a refrigerant system with the refrigerant they usually accumulate in the: Condenser The advantage of forced draft cooling tower over natural draft cooling tower is: Smaller tower size The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system when it is in operation when: 30 | P a g e Open suction valve, open discharge valve gradually Of the following, the major advantage of a shell and coil condenser is: There is less dangers of developing leaks An engineer needs to vary the flow of refrigerant in a refrigeration system. which operation in the flow of the system does not include: Solenoid valve thermal bulb is attached to the suction pipe between the evaporator coil and the compressor by an insulated line. assume that the machinery room is at 85F. break down of the insulation results in: Flood the evaporator A chill water system uses refrigerant R134 a leak in the evaporator shell may result in: Set off the refrigerant monitor alarm What are steam ejector used for on the surface condenser of a system with a turbine: To create a proper opening exhaust system Water and moisture is serious problem in a refrigerant system how to avoid: Proper evacuation at the charging of the system The most important requirements for a good evaporator is that: It must have enough cooling surface to absorb the required heat While on duty a refrigeration engineer notice that the suction line to the compressor and part of the compressor itself is frosted of the following, the most likely reason for this condition would be: There is not enough refrigerant in the system While doing a routine line inspection, the engineer notices the bulb of the TXV on the floor refrigerant engineer should attach bulb at the : The outlet end of the coil To convert water 32F to ice at the same temperature a refrigeration system must remove: The latent heat of fusion The use of oil in the refrigeration machine is to: Reduce wear and friction in the compressor parts The following is a desirable property in a refrigeration High latent heat The cooling medium for an evaporative condenser is: 31 | P a g e Air and water The ratio of the actual pressure of water vapor in the atmosphere to the saturated pressure of give temperature is: Relative humidity The only refrigerant/ temperature chart available to a refrigerant engineer list the temperature is degrees Celsius if the chart indicates a Celsius temperature of 4 degrees to equivalent to F: 39.2 degrees A refrigerant engineers was instructed to charge of 60 ton plant with R134A refrigerant. the refrigerant engineer will most likely find the charging valve on the Low pressure side of the system A refrigerant engineer verifies that a chilled water pump is cavitating. of the following the most likely cause for this condition is: Water leaks through the mechanical seals There is a decrease in the efficiency of a reciprocating compressor. this most likely caused by: Leaking suction valve The suction and discharge valve of the reciprocating compressor are mounted as follows: Discharge valves on top of the valve plate and suction valve below You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. while making your rounds you notice that the discharge pressure of your condenser water pumps is significantly lower than normal. which of the following action would you avoid taking: Put on an additional surface condenser pump and lower the chilled water set point A water pump is discharge against head 92 feet of water, this is approximately to a pressure of: 40 psi Which of the following will connect to the middle port on a gauge manifold? Vacuum pump The most important reason for installing a muffler in a reciprocating refrigerant machine is: To contain the compressor pulsation noise Of the following, the statement that most accurately characterize a hermetic compressor is that it: Will have both the compressor and motor enclosed is gas tight housing In the picture the valve is in what position (45 degree angle to the left) 32 | P a g e The valve is crack open What is the order of components on the liquid line of a reciprocating system from the condenser to the TEV? King valve, filter drier, solenoid valve, sight glass A high-side float valve is used to maintain: Constant level of refrigerant in the evaporator Picture of pump: Ninety degree reducing elbow, pump suction, pump casing, pump discharge, check valve Picture of compressor: Oil charging port allows for the addition and removal of oil from the compressor A facility has failed to maintain water treatement to a refrigerant system: Increase in the condenser pressure Which of these compressors is not a positive displacement type compressor? Centrifugal Where is emergency power not required according to code? Data centers What is the most widely used regulation book by operating engineers is? EPA What type of refrigerant do you need FDNY approval for? Propane Centrifugal pressure is determined by? Speed of motor A single phase 208 VAC circuit has 2 hot wires and the third is? Ground Liquid refrigerant that has passed through a meter device is a ? Low pressure saturated liquid With a 75 degree dry bulb and a 73 degree wet bulb the relative humidity is? Very high After recovering liquid refrigerant from a centrifugal chiller the next step is to? 35 | P a g e When is a chemical fire extinguisher system needed? Where water is not sufficient What is most accurate about fire alarm books? Must be kept in the fire alarm panel What is the volume of a box 12" x12" x12" measure? 1 cubic foot A condenser pump is supplied with 85 degree water from a cooling tower and returns to the tower at 88 degrees engineer is sure the condenser tubes are clean and free of obstructions. the condenser has high condenser pressure. the reason for this could be? Over charge of refrigerant Fireproof decorations n buildings is useful for? Don't catch fire in an emergency What is the lowest temperature a cooling tower can be? Wet bulb temperature Manifold hoses should be equipped with? Low loss fittings Water regulating valves are used to? Maintain condenser pressure to pre-determined level What type of sprinkler system needs inspecting? Automatic You are performing hot works near a sprinkler head. what can you do to prevent the fire alarm from going off? Take the building offline How long does it take to warm up a steam turbine? 10-15 minutes Why is a pressure relief valve better that a fusible plug? Minimizes refrigerant loss What is the state of refrigerant entering the compressor on a reciprocating machine? Superheated vapor In the absence of water chemical treatment of a cooling tower? 36 | P a g e Drain tower every one to two weeks & replace with fresh water What is ammonia's refrigerant ASHRAE classification? B2 What is the function of a safety head on a compressor? Prevents liquid slugging from damaging the valve plate What does a wiring diagram display? Wiring of components Filter driers remove Moisture and particles Show a picture of an insulated pump and ask what is this pump? Centrifugal chill water pump IF 29.92'HG is equal to 14.7 Psia then 26"HG converts to what in Psia? 12.77 When charging refrigerant on the low side of a reciprocating machine with manifold gauges, what is the position of the manifold? High side frontseated low side backseated You are the engineer running a 2000 ton steam-driven turbine centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. you are supplying 46 degree chilled water. all the buildings are satisfied except one building. what action should the engineer do? Put an additional chilled water pump online The cooling medium for a cooling tower is? Air The charge in a TEV sensing bulb is? Similar to refrigerant in system When you finished leak testing with R22 and nitrogen the next step should be? Vent refrigerant and nitrogen to open air What is the device used to measure the speed of a turbine? Tachometer 37 | P a g e The condenser pump is on the first floor and not running. the pressure gauge shows 55 psi. there is 15 feet for each floor. what floor is the cooling tower on? 8 There is 7.48 gallons per cubic foot. how many gallons of water are in a pipe 8 feet in diameter and 10 feet long? 3758 A technician had been asked to estimate the cost of operating a 5 horse power motor. because the plant is build by energy consumed as kiliowatt-hours, the technician will have to calculate the conversion. the equivalent in energy of a 5 horse power motor operating for 9 hours in kiliowatt-hours is closest to: 33.6 A standpipe system will be out of service for two days. how long should there be a fire watch? The entire time the standpipe is out of service A circuit breaker has a similar function as what? A fuse How do you start a centrifugal chiller? Start the chilled water pump, start the condenser water pump, check oil, start cooling tower, start compressor If a sprinkler system is offline for two days how often do you need to inspect it until it is returned back to service ? Continuously 24 hours a day until system is restored The only refrigerant/temperature chart available to a refrigerant engineer lists the temperature in degrees Celsius. if the chart indicates a Celsius temperature of 5 degrees the equivalent in Fahrenheit is? 41 degrees In the picture below what does the equipment detect? Refrigerant leaks In building with a multizone standpipe system, how does each zone get supplied with water? Each zone will have its own automatic water supply Which service valve should be installed to isolate a dual pressure relief valve while keeping system in service? Three way valve When will the BTU's exchanged be the greatest? low evaporator temperature, high condenser temperature