Q-01 FDNY Exam Ques ons and answers Updated
RATED A+ 2026
Rupture members, when used in parallel with a relief valve, are not to exceed _____% above
designed working pressure
20%
Bu erfly valve: where can it be used?
Can be used on the inlet and outlet of a water pump
What electrical motor protec&on device automa&cally resets itself?
The thermal protector
746 wa s equals how many kilowa hours?
.746 kilowa hours
What posi&on is the liquid line service valve normally in?
Back-seated
In an opera&ng 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 restric&on (such as dirt or scale) in the liquid line?
Frost immediately a4er the restric&on
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?
Suc&on side of the compressor at the Suc&on Service Valve
When comparing a brine with s PH of 8 to one with a PH of 10, its alkalinity is:
100 &mes greater (ex. PH 8 to PH 9 is 10 &mes greater)
,In an efficiently opera&ng induced dra4 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 & suc&on 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 distribu&on 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) thro ling device
C) float valve
D) pressure of the strong liquor pump
B) thro ling device
The best way of detec&ng ammonia brine is by using
A) CO2 gas
B) potassium of lime
C) Nessler reagent
D) carbonate of soda
C) Nessler reagent
The best &me 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 opera&on
D) none of the above
C) during opera&on
,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, installa&on and repairs
B) Brine is a liquid cooled by refrigera&on and used for the transmission of heat
C) A fusible plug has a set-temperature fusible member to relieve pressure
D) A rupture member automa&cally ruptures at a predetermined temperature
D) A rupture member automa&cally 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 seFng of a fusible plug is
A) 280° F
B) 300° F
C) 380° F
D) 300 psig.
A) 280° F
If the insula&on 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 insula&on 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 solu&on-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 loca&on of this dryer is on the
A) high-pressure line between condenser and reciever
B) suc&on 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 characteris&cs of a refrigerant:
A) High __________
B) Low __________
A) High cri&cal point
B) Low freezing point
Centrifugal Feed Water Pump
A) Start-up procedure
B) Shut-down procedure
RATED A+ 2026
Rupture members, when used in parallel with a relief valve, are not to exceed _____% above
designed working pressure
20%
Bu erfly valve: where can it be used?
Can be used on the inlet and outlet of a water pump
What electrical motor protec&on device automa&cally resets itself?
The thermal protector
746 wa s equals how many kilowa hours?
.746 kilowa hours
What posi&on is the liquid line service valve normally in?
Back-seated
In an opera&ng 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 restric&on (such as dirt or scale) in the liquid line?
Frost immediately a4er the restric&on
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?
Suc&on side of the compressor at the Suc&on Service Valve
When comparing a brine with s PH of 8 to one with a PH of 10, its alkalinity is:
100 &mes greater (ex. PH 8 to PH 9 is 10 &mes greater)
,In an efficiently opera&ng induced dra4 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 & suc&on 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 distribu&on 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) thro ling device
C) float valve
D) pressure of the strong liquor pump
B) thro ling device
The best way of detec&ng ammonia brine is by using
A) CO2 gas
B) potassium of lime
C) Nessler reagent
D) carbonate of soda
C) Nessler reagent
The best &me 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 opera&on
D) none of the above
C) during opera&on
,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, installa&on and repairs
B) Brine is a liquid cooled by refrigera&on and used for the transmission of heat
C) A fusible plug has a set-temperature fusible member to relieve pressure
D) A rupture member automa&cally ruptures at a predetermined temperature
D) A rupture member automa&cally 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 seFng of a fusible plug is
A) 280° F
B) 300° F
C) 380° F
D) 300 psig.
A) 280° F
If the insula&on 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 insula&on 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 solu&on-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 loca&on of this dryer is on the
A) high-pressure line between condenser and reciever
B) suc&on 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 characteris&cs of a refrigerant:
A) High __________
B) Low __________
A) High cri&cal point
B) Low freezing point
Centrifugal Feed Water Pump
A) Start-up procedure
B) Shut-down procedure
