1|Page
Q-01 FDNY EXAM QUESTIONS & ANSWERS | WITH 100%
CORRECT ANSWERS GRADED A+ (UPDATED 2026)
GUARANTEED SUCCESS!!
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 ......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 ......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 ......ANSWER......C) during operation
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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 ......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 ......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 ......ANSWER......D) not contain moisture
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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 ......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. ......ANSWER......A) 280° F
If the insulation was removed from the bulb of the expansion valve,
what would happen? ......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
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C) 208 volts
D) 220 volts ......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 ......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 ......ANSWER......D)
liquid line between receiver and expansion valve
R-22 —What does it smell like? ......ANSWER......Odorless
Desirable characteristics of a refrigerant:
A) High __________
Q-01 FDNY EXAM QUESTIONS & ANSWERS | WITH 100%
CORRECT ANSWERS GRADED A+ (UPDATED 2026)
GUARANTEED SUCCESS!!
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 ......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 ......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 ......ANSWER......C) during operation
,2|Page
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 ......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 ......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 ......ANSWER......D) not contain moisture
,3|Page
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 ......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. ......ANSWER......A) 280° F
If the insulation was removed from the bulb of the expansion valve,
what would happen? ......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
, 4|Page
C) 208 volts
D) 220 volts ......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 ......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 ......ANSWER......D)
liquid line between receiver and expansion valve
R-22 —What does it smell like? ......ANSWER......Odorless
Desirable characteristics of a refrigerant:
A) High __________
