Z-51 Written Exam Questions and Complete Solutions.

Z-51 Written Exam Questions and Complete Solutions In a steam turbine, what is the function of a Kingsbury thrust bearing? A) Maintain first stage steam pressure. B) Compensate for coupling misalignment. C) Adjust shaft torque at start up. D) Maintain axial positioning of the rotor shaft. - Answer: D) Maintain axial positioning of the rotor shaft. The ratio of actual pressure of water pressure in the atmosphere to the saturated pressure of given temperature is A) partial pressure. B) relative humidity. C) humidity effect. D) absolute humidity. - Answer: The total amount of heat to be removed from the refrigerant in a condenser equals the heat picked up in the A) evaporator plus the heat of compression. B) evaporator. C) evaporator plus the heat of included non-condensable. D) evaporator less the heat given up in the muffler. - Answer: When must the Fire Department be notified that a fire protection system is out of service? A) The manual pull alarm station in the lobby will be out of service for 4 hours. B) Four sprinkler heads on a same floor of your building will be out of service for 2 hours. C) The sprinkler system will be out of service on 1st and 2nd floors. D) The fire alarm system is out of service in the refrigerating system room for g hours. - Answer: C) The sprinkler system will be out of service on 1st and 2nd floors. Hot work authorizations are issued by A) a Responsible Person designated by the Building Owner. B) a Building Department inspector. C) a FDNY inspector. D) the Building owner's insurance company. - Answer: A) a Responsible Person designated by the building owner. Insecticidal fogging operations are hazardous because chemicals A) are corrosive. B) are water-reactive. C) may be toxic. D) are highly unstable. - Answer: C) may be toxic. What is a compressor safety head? A) Rupture disc. B) A pressure relief valve on the low side. C) Cylinder head with a low pressure relief on the high side. D) A spring on the valve plate. - Answer: The oil collected in an oil separator is generally A) caused by an oil overcharge. B) returned to the compressor. C) filtered and returned to the compressor. D) drained and replaced by fresh oil. - Answer: Where is emergency power not required according to code? A) Fire pumps. B) High rise elevators. C) Egress illumination. D) Data centers. - Answer: D) Data centers. Modern compressors usually seal the rotating shaft seal as it exits the compressor housing a spring-loaded seal made of A) low-friction plastic. B) rubber. C) metal or carbon. D) graphite-loaded fiber. - Answer: A technician shows up to service the fire alarm panel in your building. What COF qualifications must he/she have? A) A Q-01/Q-99 Certificate of Qualification holder who is designated by the building owner. B) A certified Fire Safety Director who is designated by the building owner. C) A S-95 Certificate of Fitness holder who is employed by a FDNY certified company. D) A S-97/S-98 Certificate of Fitness holder who is employed by a FDNY certified company. - Answer: D) A S-97/S-98 Certificate of Fitness holder who is employed by a FDNY certified company. Which statement is correct regarding a fusible plug on a condenser? A) The melting point is marked on it. B) Are not allowed by code. C) Release refrigerant by pressure. D) Can be back-seated. - Answer: In an office building, the display of cut natural trees (Christmas trees) is A) never allowed. B) allowed provided they are removed once they dry out. C) always allowed. D) allowed during the holiday season. - Answer: A) never allowed. Describe the equipment's function in the picture. A) Control flow of refrigerant to the compressor. B) Remove non-condensable from the condenser. C) Relieve excess pressure from the condenser. D) Relieve excess pressure from the evaporator. - Answer: B) Remove non-condensable from the condenser. When the expansion valve is operating properly, the end of the evaporator will contain A) only superheated vapor. B) saturated liquid refrigerant C) only vapor. D) only liquid refrigerant. - Answer: A) only superheated vapor. How much extra refrigerant con be stored in a machine room? A) 330 lbs. B) The amount equal to the design pressure. C) 20% above normal charge. D) 220 lbs. - Answer: C) 20% above normal charge. 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 by the A) temperature and pressure controls. B) refrigerant charge. C) cooling tower operation. D) liquid-line solenoid valve. - Answer: A) temperature and pressure controls. The use of oil in the refrigeration machine is to A) Add non-condensates to refrigerant. B) Mix the oil with liquid refrigerant. C) Reduce wear and friction in compressor parts. D) None of the answers are correct. - Answer: C) Reduce wear and friction in compressor parts. The heat removed from the refrigerant condenser is A) latent heat only. B) sensible heat only. C) sensible and latent heat. D) Radiant heat only. - Answer: C) sensible and latent heat. Which service valve should be installed in a dual pressure release valve while keeping system in service? A) Two-way valve. B) Plug valve. C) Three-way valve. D) Stop valve. - Answer: C) Three-way valve. The monthly quick check of a fire extinguisher does NOT include A) Checking the extinguisher for damage. B) Confirming its proper location. C) Discharging the extinguisher. D) Ensuring it is clear from any obstructions. - Answer: C) Discharging the extinguisher. Several components of a sprinkler system in an office building need to be repaired. Which of the following are allowed to perform the repair work? A) A Q-01 refrigeration engineer holding S-12 CoF. B) A Master Fire Suppression Contractor holding S-12 CoF. C) Any Master Fire Suppression Piping Contractor. D) A S-12 CoF holder without any other license. - Answer: B) A Master Fire Suppression Contractor holding S-12 CoF. A FDNY permit is required to conduct hot work for A) brazing. B) welding. C) use of oxygen and flammable gas. D) All answers are correct - Answer: D) All answers are correct Which of the following correctly describes the object in the picture below? A) Carbon dioxide system nozzle, to extinguish electrical fires. B) Cooling tower makeup valve, to put out fires in case of emergency. C) Standpipe hose outlet, to put out fires in case of emergency. D) Water chemistry supply station, for condenser water. - Answer: C) Standpipe hose outlet, to put out fires in case of emergency. While on duty, a refrigerant engineer notices that the suction line to the compressor and part of the compressor is frosted. Of the following, the most likely reason for this condition is A) the TEV is almost closed. B) overcharge. C) there is a blockage in the liquid line D) low condenser water temperature. - Answer: B) overcharge. You find that the check valve on a centrifugal pump is leaking. When will the most damage be caused to the pump? A) When another pump is turned on. B) On shutdown. C) When servicing the pump. D) On startup. - Answer: D) On startup. What is the lowest temperature the water in the cooling tower can be? A) Ambient. B) Between wet and dry bulb. C) Dry bulb. D) Wet bulb. - Answer: B) Between wet and dry bulb. The most important reason to subcool the refrigerant in the condenser is to ensure that A) liquid slugs will not enter the compressor. B) the cooling tower has sufficient water. C) the condenser is working efficiently. D) a pure liquid refrigerant will enter the metering device. - Answer: D) a pure liquid refrigerant will enter the metering device. A chilled water system that has an air cooled condensing unit on a roof during cold weather has what type of protection? A) Glycol running through it. B) Air-limiting device. C) Heater coil. D) Resistor. - Answer: B) Air-limiting device. An engineer observes a gauge that reads saturation pressure of a refrigerant. If chilled water is circulated as the cooling medium, this reading can best be used to estimate the A) chilled water return from building spaces being pumped to the spaces being cooled. B) cooling tower efficiency. C) pressure of chilled water being pumped to spaces being cooled. D) temperature of chilled water being pumped to the spaces being cooled. - Answer: D) temperature of chilled water being pumped to the spaces being cooled. The purpose of wear rings in a centrifugal pump is to A) act as a bearing to reduce axial motion after wear occurs. B) prevent wearing of the pump housing and impeller. C) center the impeller in the pump casing. D) minimize water leakage around the shaft. - Answer: B) prevent wearing of the pump housing and impeller. Of the follow, an example of an in-line refrigerant cleaning system that may be used with a centrifugal compressor containing R123 refrigerant is: A) Refrigerant reclaiming. B) Refrigerant disposal. C) Refrigerant recycling. D) Refrigerant recovery. - Answer: C) Refrigerant recycling. Refrigerating system refrigerant detection systems must be tested at least A) annually. B) monthly. C) daily. D) weekly. - Answer: B) monthly. Capacitors are used on refrigeration motors. Of the following, the function of these devices is to A) store electrical charges during starting and running the motor. B) act as inductive devices to cause the motor current to lag the voltage. C) convert electrical to magnetic and then to mechanical energy. D) defrost refrigerant cooled motors. - Answer: A) store electrical charges during starting and running the motor. Liquid refrigerant that has passed through a metering device is a A) high-pressure liquid. B) low-pressure saturated liquid. C) subcooled liquid. D) low-pressure vapor. - Answer: B) low-pressure saturated liquid. Why are mirrors prohibited to be placed on exit doors? A) It will be difficult to keep the mirrors clean. B) The mirrors will cause major obstructions for the first responders. C) The mirrors will break easily. D) The mirrors will confuse the direction of exit. - Answer: D) The mirrors will confuse the direction of exit. What is ammonia refrigerant's ASHRAE classification? A) B3 B) A1 C) B2 D) A3 - Answer: C) B2 Wet chemical fire extinguishing systems are commonly installed to protect A) commercial cooking equipment. B) flammable liquid storing rooms. C) com outer rooms. D) battery rooms. - Answer: A) commercial cooking equipment. If resistance is cut in half, what happens to the power factor? A) Increases by a factor of two. B) Decreases by a factor of two. C) Gets cut by half. D) Increases by two. - Answer: A) Increases by a factor of two. An electrically operated control requires 24 volts to operate. To change the available 110 volts to 24 volts requires a A) rectifier. B) transformer. C) low-temperature wire. D) step-down capacitor. - Answer: B) transformer. Which of the following personnel is qualified to supervise the inspection, testing and maintenance of emergency power systems? A) A F-01 CoF holder. B) A S-95 CoF holder. C) A Q-01 CoF holder. D) Anyone who is designated by the building owner. - Answer: C) A Q-01 CoF holder. The most important reason to use at least two compressors in a cascade system is to A) avoid the need for a water-cooled condenser. B) divide the cooling load between the compressors. C) accomplish higher temperature. D) avoid very high compression ratio for each compressor. - Answer: D) avoid very high compression ratio for each compressor. Where must the Material Safety Data Sheets be located? A) Where any toxic material is used. B) Near the entrance to the machine room. C) Where flammable liquids are used. D) Where available to all employees. - Answer: D) Where available to all employees. If a sprinkler system is offline for two days, how often do you need to inspect until it is returned to service? A) 12-hours a day until system is restored. B) Continuously, 24-hours a day until system is restored. C) Only in the evening, until restored. D) Only in the morning, until restored. - Answer: B) Continuously, 24-hours a day until system is restored. Where is the muffler located? A) After the condenser. B) Before the compressor. C) Between the evaporator and condenser. D) Between the compressor and condenser. - Answer: D) Between the compressor and condenser. On an operating centrifugal compressor refrigerant unit, the refrigeration engineer notices that the compressor is short-cycling. The unit is using the low-side float valve as a metering device. Of the following requirements, this would indicate that A) the system is undercharged with refrigerant. B) the system is overcharged with refrigerant. C) an inspection should be made for a dirty and partially plugged discharge line. D) the compressor wiring should be inspected. - Answer: A) the system is undercharged with refrigerant. What should be done to prevent accidental activation of smoke detectors during hot work operation? A) Place fire alarm system out of service, notify the Central Watch Station and provide fire watch. B) Remove the batteries from the smoke detectors. C) Cover the smoke detectors with plastic bags. D) Inform the Central Station to ignore any fire alarm signal during the hot work operation. - Answer: A) Place fire alarm system out of service, notify the Central Watch Station and provide fire watch. Under normal conditions, the refrigerant enters the compressor as a A) low-pressure, superheated vapor and leaves as a high-pressure vapor. B) high-temperature vapor and leaves as a low-pressure vapor. C) low-pressure, superheated vapor and leaves as a high-pressure, saturated liquid. D) low-pressure vapor and leaves as a high-pressure saturated vapor. - Answer: A) low-pressure, superheated vapor and leaves as a high-pressure vapor. The total amount of heat to be removed from the refrigerant in a condenser equals the heat picked up in the A) evaporator plus the heat of compression. B) evaporator. C) evaporator less the heat given up in the muffler. D) evaporator plus the heat of included non-condensable. - Answer: A) evaporator plus the heat of compression. Which of the following requires a FDNY permit? A) Battery system. B) Refrigerating system. C) Standpipe system. D) Sprinkler system. - Answer: B) Refrigerating system. Which of the following is a correct statement? A) 2.5 gallons of water weighs 10.7 lbs. B) 2.5 gallons of water is 2.5 cubit feet. C) 2.5 gallons of water weighs 1.05 lbs. D) 2.5 gallons of water weighs 20.8 lbs. - Answer: D) 2.5 gallons of water weighs 20.8 lbs. A chilled water system uses refrigerant R134a, a leak in the evaporator shell may result in A) higher than normal high-side pressure. B) a foam of ice around the point of the leak. C) low-pressure shutdown. D) set off the refrigerant monitor alarm. - Answer: D) set off the refrigerant monitor alarm. The packing gland of a centrifugal pump serves to A) All of the answers are correct. B) keep the air out of the pumps when the impeller housing is under negative pressure. C) the drip part of the packing gland gives evidence that there is water in the pump. D) keep the bearing cooled. - Answer: C) the drip part of the packing gland gives evidence that there is water in the pump. The installation of an inline refrigerant cleaning system is advisable A) to purge non-condensables. B) for high-pressure refrigerant systems. C) for systems using toxic refrigerant. D) to remove impurities from the system. - Answer: D) to remove impurities from the system. A refrigeration engineer is running two centrifugal water pumps in parallel. One of the pumps is running at 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) for the pump components to maintain both the flow rate and the discharge pressure. B) a reduction in the water pressure at the condenser inlet. C) a reduction on the total flow rate to the condenser. D) a reduction in both the water flow rate and pressure to the condenser. - Answer: C) a reduction on the total flow rate to the condenser. When entering Phase 2 fireman's service, which statement is correct? A) Can only be used by a firefighter. B) Must be tested semi-annually. C) Does not need a special key. D) The elevator operator is the only person that could control the elevator. - Answer: D) The elevator operator is the only person that could control the elevator. In a building with a multizone standpipe system, how is each zone supplied water? A) It will supply only the highest standpipe zone. B) Each zone will have its own automatic water supply. C) Each zone will be connected to the main water supply. D) It will supply only the lowest standpipe zone. - Answer: B) Each zone will have its own automatic water supply. The amount of electrical power used to operate a solenoid valve or motor is measured in A) amperes. B) ohms. C) foot pounds. D) volts. - Answer: D) volts. The suction service valve of a reciprocating compressor is front-seated and the compressor runs until the low-pressure cut-out shuts the compressor off. When the machine is off, the refrigeration engineer notices that the suction pressure increases rapidly. The most probable cause of the pressure rise is A) a leaky suction service valve. B) a faulty gauge. C) All answers are correct. D) the malfunction of a compressor valve. - Answer: D) the malfunction of a compressor valve. What happens when a steam turbine reaches critical speed? A) The turbine will slow down. B) The turbine will vibrate violently. C) The turbine will shut down. D) The turbine will speed up. - Answer: B) The turbine will vibrate violently. Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity? A) B2 B) A3 C) A1 D) B1 - Answer: C) A1 Water regulation valves are used to A) maintain refrigerant temperature. B) maintain low-side pressure to proper level. C) vary flow based on water temperature. D) maintain condenser pressure to a predetermined level. - Answer: D) maintain condenser pressure to a predetermined level. How would you calibrate a thermometer? A) Place the thermometer in a cup of hot water. B) Place the thermometer in superheated steam. C) Place the thermometer in a cup of ice water. D) Compare temperature to another thermometer. - Answer: C) Place the thermometer in a cup of ice water. An equalizer line on a TXV is used to A) Compensate for the pressure drop across the evaporator coil. B) Eliminate the pressure across the evaporator. C) Equalize the pressure across the TXV diaphragm or bellow. D) correct for pressure drop in the thermal bulb capillary lines. - Answer: A) Compensate for the pressure drop across the evaporator coil. Transfer switches of the emergency power system must be tested semi-annually. Which is the correct statement regarding the testing procedure? A) Manually operate the switch from the standard position to the alternate position and then to return back to the standard position, B) Manually operate the switch from the standard position to the alternate position and leave it in the alternate position until the next test. C) Electrically operate the switch from the standard position to the alternate position and the return back to the standard position. D) Electrically operate the switch from the standard position to the alternate position and leave it in the alternate position until the next test. - Answer: C) Electrically operate the switch from the standard position to the alternate position and the return back to the standard position. A __________ system is piping installed in a building that serves to transfer water to hose connections located within the building for firefighting purposes. A) sprinkler B) standpipe C) hydrant D) water mist - Answer: B) standpipe The cause of a starved evaporator might be A) low refrigerant charge. B) high refrigerant charge. C) superheat that is too low. D) high condenser water temperature. - Answer: A) low refrigerant charge. When charging refrigerant on the low-pressure side of a reciprocating machine with manifold gauges, what is the position of the manifold? A) High-side and low-side front-seated. B) High-side, front-seated and low-side, back-seated. C) High-side, back-seated and low-side, front-seated. D) High and low back-seated. - Answer: B) High-side, front-seated and low-side, back-seated. A reciprocating compressor cylinder has a 10-inch more and a 14-inch stroke. The volume of the refrigerant, in cubic inches, will be close to A) 1808 B) 1406 C) 1099 D) 1002 - Answer: C) 1099 If R134a comes in contact with a refrigeration engineer's skin, what first aid should be applied from the MSDS? A) R134a is a low acute toxicity, so no special medical attention is required. B) Promptly flush skin with water until all chemical is removed. C) Rub the frozen parts. D) Place the frostbitten parts in hot water (above 130F) to warm them up. - Answer: B) Promptly flush skin with water until all chemical is removed. The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system when it is operation only when A) lunch or dinner occur. B) the assistant provides coverage or supervision. C) relieved by another licensed refrigeration engineer. D) system is in automatic operation. - Answer: C) relieved by another licensed refrigeration engineer. The 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 85*F.; breakdown of the insulation results in A) excessive superheat. B) a starved evaporator. C) a flooded evaporator. D) adequate superheat. - Answer: A) excessive superheat. Of the following, centrifugal refrigerant machines are best characterized by A) the use of an air-cooled condenser. B) the low and high operating pressures. C) high-volume, low-pressure machine. D) use of refrigerant for direct cooling of the occupied space. - Answer: C) high-volume, low-pressure machine. When is a chemical fire extinguisher system needed? A) Where water is not sufficient. B) High-rise office buildings. C) Deluge systems. D) Pre-action systems. - Answer: A) Where water is not sufficient. The standpipe certificate should be available for A) FDNY and OSHA. B) FDNY and Building Inspector. C) FDNY and EPA. D) FDNY and NFPA. - Answer: B) FDNY and Building Inspector. As an engineer, you notice that the pressure drops across the evaporator. You check and notice the external equalized line is disconnected. What will occur in the evaporator? A) The evaporator will stabilize. B) The evaporator will flood. C) The evaporator will be unaffected. D) The evaporator will starve. - Answer: B) The evaporator will flood. A water pump is discharging against head 92-feet of water. This is approximately to a pressure of A) 20 psi. B) 95 psi. C) 40 psi. D) 180 psi. - Answer: C) 40 psi. A refrigerant engineer verifies that a chilled water pump is cavitating. The most likely cause of this condition is A) too long a period between pump servicing. B) operating at sustained high loads. C) a faulty cooling tower water level controller. D) water leaking through mechanical seals. - Answer: B) operating at sustained high loads. Capacity control of a reciprocating hermetic compressor is typically achieved through A) regulating the opening of the discharge valve. B) regulating the opening of the TXV. C) variation of the condenser water temperature. D) operation of the hot gas bypass valve. - Answer: D) operation of the hot gas bypass valve. You are performing hot work near a sprinkler head. What can be done to prevent the fire alarm from going off? A) Drain the sprinkler system in that area. B) Use a noncombustible barrier to protect the sprinkler head. C) Perform hot work in service area. D) Take the building offline. - Answer: B) Use a noncombustible barrier to protect the sprinkler head. Which of the following does not require flame resistant treatment? A) Decorations in a building lobby. B) Artwork in a museum. C) Decorations in a hotel lobby. D) A heavy curtain in a theater. - Answer: B) Artwork in a museum. A centrifugal compressor is in operation with a suction pressure of 3 psig and discharge pressure of 10 psi. If the atmospheric pressure is 14.7, which is the compression ratio closest to? A) 2.31 B) 2.35 C) 1.39 D) 0.89 - Answer: C) 1.39 A condenser pump is supplied with 85*F water from a cooling tower and returns to the tower at 88*F. The engineer is sure the condenser tubes are clean and free of obstructions. The condenser has high pressure. The reason for this could be A) a wide open regulation valve. B) overcharged refrigerant. C) undercharged refrigerant. D) the thermostat is damaged. - Answer: B) overcharged refrigerant. What is the volume of a 12"x12"x12" box? A) 144 cubic feet. B) 1 cubic foot. C) 1,728 inches. D) 1,728 square inches. - Answer: B) 1 cubic foot. Which of the following building occupancies requires and EAP Director to implement the Emergency Action Plan? A) An office building greater that 75-feet in height. B) A college dormitory. C) A 4-story hotel building. D) A homeless shelter. - Answer: A) An office building greater that 75-feet in height. Assume that a refrigeration engineer has a choice of four valves to choose from. Which of the following is the most effective to control pressure? A) Ball valve. B) Plug valve. C) Quarter-turn valve. D) Gate valve. - Answer: B) Plug valve. Select the correct statement regarding the maintenance of means of egress. A) Storage of noncombustible materials is allowed in stairways. B) Q-01 holders are responsible for maintaining all door hardware in good, working order. C) Decorations must not be placed to obstruct exits. D) Metal file cabinets are allowed to be stored in corridors. - Answer: C) Decorations must not be placed to obstruct exits. The primary way of achieving capacity control of a centrifugal compressor is by: A) Operation of the hot gas bypass valves. B) Adjustment of the thermal expansion valve. C) Variation in steam pressure. D) Adjustment of the impeller inlet pre-rotation vanes. - Answer: What is the function of the turbine auxiliary oil pump? A. Standby if the main pump fails B. Check proper oil level in pump before startup C. Recovers oil from the condensate tank D. Establish oil pressure during turbine startup - Answer: The most likely reason for a refrigeration engineer to use a psychrometer is to measure: A) Relative humidity level of the atmosphere B) Temperature of the atmosphere C) Atmospheric pressure D) Undesired substance in the atmosphere - Answer: The cooling medium for a cooling tower is: A) Water B) Tower fan C) Air and Water D) Air - Answer: An engineer suspects a short in the motor winding has caused the motor to trip on overload. The engineer should use what instrument to check the motor? A) Vaultmeter B) Capacitor C) Ohmmeter D) Ammeter - Answer: The only refrigerant/temperature chart available to an engineer lists the temperature in degrees Celcius. If the chart indicates a Celsius temperature of 4 degrees, what is the equivalent in Fahrenheit? A) 35.2 degrees B) 18.4 degrees C) 39.2 degrees D) 27.0 degrees - Answer: Which of the following ASHRAE refrigerant safety classifications is the most flammable? A) A1 B) A3 C) B1 D) B2 - Answer: FDNY is most concerned with which ASHRAE refrigerant classification? A) B1 B) A3 C) B2 D) A1 - Answer: Non-condensible gases like air, oil vapor or nitrogen travel through a refrigerant system with the refrigerant. They usually accumulate in the A) Compressor crankcase B) Evaporator C) Condenser D) Filter drier - Answer: The total amount of heat to be removed from the refrigerant equals the heat picked up in the: A) Evaporator less the heat given up in the muffler. B) Evaporator plus the head of included non-condensables. C) Evaporator plus the heat of compression. D) Evaporator. - Answer: C) Evaporator plus the heat of compression. Select the INCORRECT statement regarding requirements of commercial cooking exhaust systems A) Company servicing the system myst be certified by the FDNY, but the individual technicians are not. B) A permit is required to operate commercial cooking systems. C) The exhaust systems must be cleaned periodically. D) Instructions for manual operation of the fire extinguishing system must be posted. - Answer: A centrifugal water pump is known as a lift pump when A) the pump is started iwht the suction valve open. B) the water supply to the pump suction inlet is below the pump level. C) the pump lifts the water into the pump. D) the discharge head exceeds 150 feet. - Answer: You have a cold front and a sudden drop in temperature. The thermostat will cause the solenoid valve to A) Close and pump the compressor down and shut down on low pressure. B) Open and the compressor goes down on high pressure. C) Open and the compressor will continue to run at a reduced speed. D) Close and the compressor will stop on high pressure. - Answer: Which of the following would you connect to the middle port on a gauge manifold? A) King valve. B) Vacuum pump. C) Solenoid valve. D) Suction or discharge valves. - Answer: B) Vacuum pump. An automatic expancion valve maintains a constant A) Evaporator pressure B) Evaporator superheat C) Refrigerant flow D) Evaporator pressure drop - Answer: The only Q-01 Certificate of Qualification holder on duty in the building is asked by the Chief Engineer to leave the building to purchase a plumbing tool. What immediate action should the Q-01 Certificate of Qualification holder take consistent with the New York City Fire Code? A) Comply with the Chief Engineer's instruction only if he/she can return in less than 30 minutes. B) Not leave the building while the refrigerating system is in operation. C) Since it is an emergency repair, he/she should purchase the tool as the Chief Engineer instructed. D) Call Central Station, make a written entry in the log book and comply with the Chief Engineer's instrucion. - Answer: In an indirect refrigeration system, of the the following, the one that would not be used as a cooling medium for the building spaces being cooled is A) A sodium chloride solution B) R22 refrigerant C) A Calcium Chloride solution D) Glycol - Answer: You are the engineer running a 2000 ton steam turbine, centrifugal refrigeration system. A refrigeration system supplies chilled water to a college campus with multiple buildings. The panel displays on the refrigeration system indicates that the problem is water flow. What do you do? A) Call in a service contractor. B) Check the condenser water pump and restart the refrigeration system. C) Leave the refrigeration system off for 2 hours before attempting to restart D) Decrease the chilled water set point, and restart the refrigeration system. - Answer: A) B) C) D) - Answer: A TXV is used to maintain constant A) Refrigerant flow B) Evaporator pressure C) Evaporator superheat D) Evaporator pressure drop - Answer: A refrigeration engineer verifies that a condenser water pump is cavitating. Of the following, the most likley cause for the condition is A) Refrigerant leaks through the pump's packing B) Too long a period between pump servicing C) Operating at sustained high loads D) A faulty cooling tower water level controller - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: What is the purpose of means of egress in a building? A) It improves better natural ventilation. B) It provides the building occupants a pleasant working environment. C) It provides building occupants a continuous and unobstructed way of exit. D) It is used only in a building higher than 100 feet for exit purposes. - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: The chilled water supply to the building is 55 F. If the chiller is being used for human comfort, should you be concerned about this and why? A) No, 55 F is within an acceptable range. B) Yes, this temperature is too low for human comfort purposes. C) No, temperature gauges often give false high readings. D) Yes, this temperature is too high for human comfort purposes. - Answer: 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 high. Of the following, the one that may be causing this set of conditions: A) Faulty compressor valves B) The purge unit operation C) The condenser operation, dirty tubes or cooling control D) An expansion valve that is too wide. - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: On a steam turbine, what would cause the atmospheric valve to open? A) Low vacuum in the surface condenser B) Leaking tubes in the surface condenser C) All answers are correct D) Dirty tubes in surface condenser - Answer: A single phase 208 VAC circuit has 2 hot wires. The third is the A) Common B) Control wire C) Spare wire D) Ground - Answer: What is the most widely used regulation book by operating engineers? A) NFPA B) EPA C) OSHA D) BOMA - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A centr A) B) C) D) - Answer: An engineer would expect a relief valve to start functioning at a pressure of? A) Recommended pressure for normal coolant B) 5% over design pressure C) 20% below design pressure D) Design pressure - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: With a 75 degree dry bulb and a 73 degree wet bulb, the relative humidity is A) Very low B) Normal C) Very high D) 100 - Answer: The suction and discharge valve of the reciprocating compressor are mounted as follows: A) Suction and discharge valve below valve plate B) Discharge valve on top of valve plate and suction valve below C) Discharge valve below valve plate and suction valve above it D) Suction and discharge valve on upper side of plate - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: Smoke control systems must be periodically tested under A) Battery power only B) Normal power only C) Emergency power only D) Both normal power and emergency power - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: A) B) C) D) - Answer: Phase 1 elevator emergency recall operation must be activated A) Automatically when CO detectors are activated B) Manually by central station C) Automatically when standpipe systems are in use D) Automatically when smoke detectors or the sprinkler water flow alarms are activated. - Answer: Why is a pressure relief valve better than a fusible plug? A) Less costly. B) Minimizes refrigerant loss C) Can be tested D) Adjustable - Answer: You are the only engineer with a machine running. A Vice President tells you to shovel snow. What should you do? A) Do not leave building. B) Shovel snow. C) Shovel, but check machine regularly D) Call your union rep. - Answer: A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn parts are not causing the knocking, what is the probable cause? A) Misalignment of the compressor motor B) Insufficient lubrication C) The slugging of the liquid refrigerant D) Parallel misalignment of the compressor and the motor - Answer: Why is a refrigerant gauge called a compound gauge? A) It has scales for different types of refrigerants B) You can read the pressure on the high side and the low side C) It reads positive pressure and vacuum D) You can read temperature and pressure - Answer: