FDNY z51 FINAL EXAM Questions & Answers Latest Update Already Passed

FDNY z51 FINAL EXAM Questions & Answers Latest Update Already Passed 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: - ANSWER Lowering the condensing pressure The heat removed from the refrigerant in a condenser is: - ANSWER 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: - ANSWER Are approved by the US department of transportation Which of the following best describes how the cylinder unloader work? - ANSWER 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: - ANSWER Cool the motor The amount of refrigerant that flows through the orifices of a economizer is determined by the: - ANSWER Difference between the high side and load side pressure The installation of an inline refrigerant cleaning system is advisable: - ANSWER 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 - ANSWER 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: - ANSWER 1.69 A super heated vapor is a ? - ANSWER 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: - ANSWER A faulty cooling tower water level controller A centrifugal water pump is known as a lift pump when the: - ANSWER The water supply to the pump suction inlet is below the pump level A TXV is used to maintain constant: - ANSWER 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? - ANSWER Yes, this temperature is too high for human comfort purpose The packing gland of a centrifugal pump serves to: - ANSWER 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 - ANSWER Operation of the hot gas bypass valve The most important reason to sub-cool the refrigerant in the condenser is to ensure that: - ANSWER 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. - ANSWER An expansion valve that is open to wide A low side float valve is used to maintain: - ANSWER The level of the refrigerant in the evaporator Regarding fire safety, which ASHARE refrigerant safety classification indicates no flammability and lower the toxicity? - ANSWER A1 When an expansion valve is operating properly, at the end of the evaporator will contain: - ANSWER Only superheated vapor