Q-01 FDNY Exam With 100% Correct Answers 2023
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)
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
A) gas pressure
B) throttling device
C) float valve
D) pressure of the strong liquor pump - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - 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
A) 7 to 10° F
B) 5 to 9° F
C) 20 to 30° F
D) 1 to 2° F - Correct Answer-A) 7 to 10° F
The setting of a fusible plug is
A) 280° F
B) 300° F
C) 380° F
D) 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
A) 105 volts
B) 120 volts
C) 208 volts
D) 220 volts - Correct Answer-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 - 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
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 - Correct Answer-D) liquid line between receiver and expansion valve
R-22 —What does it smell like? - Correct Answer-Odorless
Desirable characteristics of a refrigerant:
A) High __________
B) Low __________ - Correct Answer-A) High critical point
B) Low freezing point
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)
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
A) gas pressure
B) throttling device
C) float valve
D) pressure of the strong liquor pump - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - Correct Answer-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 - 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
A) 7 to 10° F
B) 5 to 9° F
C) 20 to 30° F
D) 1 to 2° F - Correct Answer-A) 7 to 10° F
The setting of a fusible plug is
A) 280° F
B) 300° F
C) 380° F
D) 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
A) 105 volts
B) 120 volts
C) 208 volts
D) 220 volts - Correct Answer-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 - 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
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 - Correct Answer-D) liquid line between receiver and expansion valve
R-22 —What does it smell like? - Correct Answer-Odorless
Desirable characteristics of a refrigerant:
A) High __________
B) Low __________ - Correct Answer-A) High critical point
B) Low freezing point
