Q-01 FDNY Exam Study Questions with 100 Correct

Q-01 FDNY Exam Study Questions with 100% Correct Answers 2023/2024 Rupture members, when used in parallel with a relief valve, are not to exceed _____% above designed working pressure - Correct Answer 20% Butterfly valve: where can it be used? - Correct Answer Can be used on the inlet and outlet of a water pump What electrical motor protection device automatically resets itself? - Correct Answer The thermal protector 746 watts equals how many kilowatt hours? - Correct Answer .746 kilowatt hours What position is the liquid line service valve normally in? - Correct Answer Back-seated In an operating evaporator, oil stays on top of which refrigerant? - Correct Answer Carbon dioxide, R- 744 At what pressure does the relief valve blow on a high pressure machine? - Correct Answer 300 psi What would indicate a restriction (such as dirt or scale) in the liquid line? - Correct Answer Frost immediately after the restriction What does solubility mean? - Correct Answer The ability of a refrigerant to mix with other substances Charging Vapor —In a compression system, where do you charge the vapor? - Correct Answer Suction side of the compressor at the Suction Service Valve When comparing a brine with s PH of 8 to one with a PH of 10, its alkalinity is: - Correct Answer 100 times greater (ex. PH 8 to PH 9 is 10 times greater) 1 / 4

In an efficiently operating induced draft cooling tower, the leaving water is between: - Correct Answer Dry bulb and wet bulb temperature To produce the desired evaporator temperature, the power input is reduced by keeping head pressure...

• Correct Answer Head pressure as low as possible & suction pressure as high as needed

The accumulator is usually between the... - Correct Answer Compressor and evaporator An oiling system in a large centrifugal system should consist of at least... - Correct Answer Reservoir, pump and distribution lines In an evaporator that chills brine, the greatest cooling effect on the brine results from the... - Correct Answer Boiling of low pressure liquid The flow of weak liquor to the absorber is controlled by

• gas pressure
• throttling device
• float valve
• pressure of the strong liquor pump - Correct Answer B) throttling device

The best way of detecting ammonia brine is by using

• CO2 gas
• potassium of lime
• Nessler reagent
• carbonate of soda - Correct Answer C) Nessler reagent

The best time to purge an ammonia plant with 250 lbs. of ammonia is

• during shut-down, because you will lose ammonia
• while charging the plant
• during operation 2 / 4

• none of the above - Correct Answer C) during operation

What will make the strong liquor in the absorber decrease?

• expansion valve open too much
• A decrease in evaporator load
• An increase in evaporator load
• Too much steam on the generator - Correct Answer B) A decrease in evaporator load

Which of the following statements is incorrect?

• A service valve is a key-operated shut-off valve used during shipment, installation and repairs
• Brine is a liquid cooled by refrigeration and used for the transmission of heat
• A fusible plug has a set-temperature fusible member to relieve pressure
• A rupture member automatically ruptures at a predetermined temperature - Correct Answer D) A

rupture member automatically ruptures at a predetermined temperature Oil in a refrigerant should

• have a high pour point
• have a low flash point
• have a high viscosity
• not contain moisture - Correct Answer D) not contain moisture

In an NH3 dry expansion evaporator with TXV and bulb clamped properly on the outlet of the evaporator, the superheat is

• 7 to 10° F
• 5 to 9° F
• 20 to 30° F
• 1 to 2° F - Correct Answer A) 7 to 10° F

The setting of a fusible plug is 3 / 4

A) 280° F

B) 300° F

C) 380° F

• 300 psig. - Correct Answer A) 280° F

If the insulation was removed from the bulb of the expansion valve, what would happen? - Correct Answer Flooded evaporator —the TXV bulb opens in a range from 45 to 85° F. If the insulation was removed, the bulb would sense the temperature in the machine room and keep the TXV open, thus flooding the evaporator.On the most common three-phase, four-wire service, the voltage between any phase and neutral should be

• 105 volts
• 120 volts
• 208 volts
• 220 volts - Correct Answer B) 120 volts

A refrigerant overcharge would

• increase head pressure
• decrease head pressure
• decrease solution-side pressure
• decrease discharge-side pressure - Correct Answer A) increase head pressure

A dryer is generally installed with other equipment in a commercial Freon compressor system. The recommended location of this dryer is on the

• high-pressure line between condenser and reciever
• suction line between evaporator and compressor
• discharge line between compressor and condenser
• liquid line between receiver and expansion valve - Correct Answer D) liquid line between receiver and

expansion valve

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