Q-01 FDNY QUESTIONS AND VERIFIED SOLUTIONS
Rupture members, when used in parallel with a relief valve, are not to exceed _____%
above designed working pressure - ✔✔20% Butterfly valve: where can it be used? - ✔✔Can
be used on the inlet and outlet of a water pump What electrical motor protection device
automatically resets itself? - ✔✔The thermal protector 746 watts equals how many
kilowatt hours? - ✔✔.746 kilowatt hours What position is the liquid line service valve
normally in? - ✔✔Back-seated In an operating evaporator, oil stays on top of which
refrigerant? - ✔✔Carbon dioxide, R-744 At what pressure does the relief valve blow on a
high pressure machine? - ✔✔300 psi What would indicate a restriction (such as dirt or
scale) in the liquid line? - ✔✔Frost immediately after the restriction What does solubility
mean? - ✔✔The ability of a refrigerant to mix with other substances Charging Vapor —In a
compression system, where do you charge the vapor? - ✔✔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: - ✔✔100 times greater (ex. PH 8 to PH 9 is 10 times greater) In an efficiently
operating induced draft cooling tower, the leaving water is between: - ✔✔Dry bulb and wet
bulb temperature To produce the desired evaporator temperature, the power input is
reduced by keeping head pressure... - ✔✔Head pressure as low as possible & suction
pressure as high as needed The accumulator is usually between the... - ✔✔Compressor
and evaporator An oiling system in a large centrifugal system should consist of at least... -
✔✔Reservoir, pump and distribution lines In an evaporator that chills brine, the greatest
cooling effect on the brine results from the... - ✔✔Boiling of low pressure liquid The flow of
weak liquor to the absorber is controlled by A) gas pressure B) throttling device C) float
valve D) pressure of the strong liquor pump - ✔✔B) throttling device The best way of
detecting ammonia brine is by using A) CO2 gas B) potassium of lime C) Nessler reagent D)
carbonate of soda - ✔✔C) Nessler reagent The best time to purge an ammonia plant with
250 lbs. of ammonia is A) during shut-down, because you will lose ammonia B) while
charging the plant C) during operation D) none of the above - ✔✔C) during operation What
will make the strong liquor in the absorber decrease? A) expansion valve open too much B)
A decrease in evaporator load C) An increase in evaporator load D) Too much steam on the
generator - ✔✔B) A decrease in evaporator load Which of the following statements is
incorrect? A) A service valve is a key-operated shut-off valve used during shipment,
installation and repairs B) Brine is a liquid cooled by refrigeration and used for the
transmission of heat C) A fusible plug has a set-temperature fusible member to relieve
, pressure D) A rupture member automatically ruptures at a predetermined temperature -
✔✔D) A rupture member automatically ruptures at a predetermined temperature Oil in a
refrigerant should A) have a high pour point B) have a low flash point C) have a high
viscosity D) not contain moisture - ✔✔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 A) 7 to 10° F B) 5 to 9° F C) 20 to 30° F D) 1 to 2° F - ✔✔A) 7 to 10° F The setting
of a fusible plug is A) 280° F B) 300° F C) 380° F D) 300 psig. - ✔✔A) 280° F If the insulation
was removed from the bulb of the expansion valve, what would happen? - ✔✔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 A) 105 volts B) 120 volts C) 208 volts D) 220 volts
- ✔✔B) 120 volts A refrigerant overcharge would A) increase head pressure B) decrease
head pressure C) decrease solution-side pressure D) decrease discharge-side pressure -
✔✔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
A) high-pressure line between condenser and reciever B) suction line between evaporator
and compressor C) discharge line between compressor and condenser D) liquid line
between receiver and expansion valve - ✔✔D) liquid line between receiver and expansion
valve R-22 —What does it smell like? - ✔✔Odorless Desirable characteristics of a
refrigerant: A) High __________ B) Low __________ - ✔✔A) High critical point B) Low freezing
point Centrifugal Feed Water Pump A) Start-up procedure B) Shut-down procedure - ✔✔A)
Start-up procedure 1) Lock-out, tag-out 2) Close discharge valve 3) Open suction valve 4)
Turn on 5) Open discharge valve B) Shut-down procedure 1) Lock-out, tag-out 2) close
suction valve 3) close discharge valve In order to vary the capacity of an absorption plant,
you should regulate the.. - ✔✔Flow of the water to the condenser 600,000 btu per hour
equals how many tons of refrigeration? A) 300 B) 3,000 C) 500 D) 50 - ✔✔D) 50 Heat
transfer takes place by A) evaporation, conduction and condensation B) radiation,
conduction and convection C) condensation, evaporation and radiation D) sublimation,
evaporation and convection - ✔✔B) radiation, conduction and convection Refrigerant
recovery is defined as A) Removing the refrigerant from a system and storing it in an
external container, with the lowest emissions possible. B) Reprocessing a refrigerant into a
new product that can be reused in another system. C) The process of cleaning a refrigerant
of dirt and contaminates, such as oil, acid, foreign material and non condensibles. D)
None of the above. - ✔✔A) Removing the refrigerant from a system and storing it in an
external container, with the lowest emissions possible. A 10-ton refrigeration unit has a
Rupture members, when used in parallel with a relief valve, are not to exceed _____%
above designed working pressure - ✔✔20% Butterfly valve: where can it be used? - ✔✔Can
be used on the inlet and outlet of a water pump What electrical motor protection device
automatically resets itself? - ✔✔The thermal protector 746 watts equals how many
kilowatt hours? - ✔✔.746 kilowatt hours What position is the liquid line service valve
normally in? - ✔✔Back-seated In an operating evaporator, oil stays on top of which
refrigerant? - ✔✔Carbon dioxide, R-744 At what pressure does the relief valve blow on a
high pressure machine? - ✔✔300 psi What would indicate a restriction (such as dirt or
scale) in the liquid line? - ✔✔Frost immediately after the restriction What does solubility
mean? - ✔✔The ability of a refrigerant to mix with other substances Charging Vapor —In a
compression system, where do you charge the vapor? - ✔✔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: - ✔✔100 times greater (ex. PH 8 to PH 9 is 10 times greater) In an efficiently
operating induced draft cooling tower, the leaving water is between: - ✔✔Dry bulb and wet
bulb temperature To produce the desired evaporator temperature, the power input is
reduced by keeping head pressure... - ✔✔Head pressure as low as possible & suction
pressure as high as needed The accumulator is usually between the... - ✔✔Compressor
and evaporator An oiling system in a large centrifugal system should consist of at least... -
✔✔Reservoir, pump and distribution lines In an evaporator that chills brine, the greatest
cooling effect on the brine results from the... - ✔✔Boiling of low pressure liquid The flow of
weak liquor to the absorber is controlled by A) gas pressure B) throttling device C) float
valve D) pressure of the strong liquor pump - ✔✔B) throttling device The best way of
detecting ammonia brine is by using A) CO2 gas B) potassium of lime C) Nessler reagent D)
carbonate of soda - ✔✔C) Nessler reagent The best time to purge an ammonia plant with
250 lbs. of ammonia is A) during shut-down, because you will lose ammonia B) while
charging the plant C) during operation D) none of the above - ✔✔C) during operation What
will make the strong liquor in the absorber decrease? A) expansion valve open too much B)
A decrease in evaporator load C) An increase in evaporator load D) Too much steam on the
generator - ✔✔B) A decrease in evaporator load Which of the following statements is
incorrect? A) A service valve is a key-operated shut-off valve used during shipment,
installation and repairs B) Brine is a liquid cooled by refrigeration and used for the
transmission of heat C) A fusible plug has a set-temperature fusible member to relieve
, pressure D) A rupture member automatically ruptures at a predetermined temperature -
✔✔D) A rupture member automatically ruptures at a predetermined temperature Oil in a
refrigerant should A) have a high pour point B) have a low flash point C) have a high
viscosity D) not contain moisture - ✔✔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 A) 7 to 10° F B) 5 to 9° F C) 20 to 30° F D) 1 to 2° F - ✔✔A) 7 to 10° F The setting
of a fusible plug is A) 280° F B) 300° F C) 380° F D) 300 psig. - ✔✔A) 280° F If the insulation
was removed from the bulb of the expansion valve, what would happen? - ✔✔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 A) 105 volts B) 120 volts C) 208 volts D) 220 volts
- ✔✔B) 120 volts A refrigerant overcharge would A) increase head pressure B) decrease
head pressure C) decrease solution-side pressure D) decrease discharge-side pressure -
✔✔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
A) high-pressure line between condenser and reciever B) suction line between evaporator
and compressor C) discharge line between compressor and condenser D) liquid line
between receiver and expansion valve - ✔✔D) liquid line between receiver and expansion
valve R-22 —What does it smell like? - ✔✔Odorless Desirable characteristics of a
refrigerant: A) High __________ B) Low __________ - ✔✔A) High critical point B) Low freezing
point Centrifugal Feed Water Pump A) Start-up procedure B) Shut-down procedure - ✔✔A)
Start-up procedure 1) Lock-out, tag-out 2) Close discharge valve 3) Open suction valve 4)
Turn on 5) Open discharge valve B) Shut-down procedure 1) Lock-out, tag-out 2) close
suction valve 3) close discharge valve In order to vary the capacity of an absorption plant,
you should regulate the.. - ✔✔Flow of the water to the condenser 600,000 btu per hour
equals how many tons of refrigeration? A) 300 B) 3,000 C) 500 D) 50 - ✔✔D) 50 Heat
transfer takes place by A) evaporation, conduction and condensation B) radiation,
conduction and convection C) condensation, evaporation and radiation D) sublimation,
evaporation and convection - ✔✔B) radiation, conduction and convection Refrigerant
recovery is defined as A) Removing the refrigerant from a system and storing it in an
external container, with the lowest emissions possible. B) Reprocessing a refrigerant into a
new product that can be reused in another system. C) The process of cleaning a refrigerant
of dirt and contaminates, such as oil, acid, foreign material and non condensibles. D)
None of the above. - ✔✔A) Removing the refrigerant from a system and storing it in an
external container, with the lowest emissions possible. A 10-ton refrigeration unit has a
