Q 01 FDNY EXAM SCRIPT 2026
COMPREHENSIVE QUESTIONS AND FULL
SOLUTIONS GRADED A+
⩥ During the re-expansion of the compressor cycle
A) The suction valve is open
B) The suction valve is closed
C) The discharge valve is open
D) None of the above
Answer: B) The suction valve is closed
⩥ Where is the king valve located? Mention some details about it.
Answer: The king valve is located next to the condenser or receiver
outlet; it can be located on the receiver; it can be used as the liquid line
service valve.
⩥ How is an evaporator defrosted?
Answer: Hot gas from the discharge line is sent to the evaporator after
the metering device.
⩥ Freon-12 has similar high and low pressures to what other refrigerant?
Answer: R-40, Methyl Chloride
,⩥ Evaporator -
1) If the pressure drop was less than 2.5 lbs., what would the system
have?
2) 2.5 lbs. but less then than 5 lbs.
3) 5 lbs. or more?
Answer: 1. Nothing
2. External equalizer
3. Multicircuit system
⩥ Oil safety switch
1) Operating pressure _____?
2) 2 pressures __.__
3) Time delay __-__
4) Cuts off at _____.
Answer: 1) Operating pressure : 20 - 25 psi
2) Low side : oil pump
3) 90 - 120 second delay
4) Cuts off at 9 - 10 PSI (15?)
⩥ What is an open compressor?
Answer: An open compressor has an external drive.
,⩥ Thermostatic expansion valves are rated in
A) Superheat settings
B) Horsepower
C) Tons of refrigeration
D) All of the above
Answer: C) Tons of refrigeration
⩥ Low pressure control
Answer: Turns the compressor off at 30 PSI; turns on the compressor at
55 PSI.
⩥ In an efficiently operating induced draft cooling tower, the leaving
water is between:
Answer: Dry-bulb and wet-bulb temperature
⩥ When comparing a brine with a PH of 8 to one with a PH of 10—its
alkalinity is ___?
Answer: 100 times greater (ex. PH 8 to PH 9 is 10 times greater)
⩥ The most accurate of the following statements about compression
ratio of a reciprocating compressor is
A) It remains constant under all compressor operating conditions
, B) It varies according to the conditions under which the compressor
operates
C) It is the ratio of the suction pressure gauge to the discharge pressure
gauge
D) It equals the saturated discharge temperature divided by the saturated
suction temperature
Answer: B) It varies according to the conditions under which the
compressor operates
⩥ Which of the following is NOT a design factor affecting compressor
capacity?
A) Compressor speed
B) Clearance space
C) Piston displacement
D) Suction and discharge valve designs
Answer: A) Compressor speed
⩥ What would indicate a restriction, such as dirt, in the liquid line?
Answer: Frost immediately after the restriction
⩥ What does solubility mean?
Answer: The ability of a refrigerant to mix with other substances
COMPREHENSIVE QUESTIONS AND FULL
SOLUTIONS GRADED A+
⩥ During the re-expansion of the compressor cycle
A) The suction valve is open
B) The suction valve is closed
C) The discharge valve is open
D) None of the above
Answer: B) The suction valve is closed
⩥ Where is the king valve located? Mention some details about it.
Answer: The king valve is located next to the condenser or receiver
outlet; it can be located on the receiver; it can be used as the liquid line
service valve.
⩥ How is an evaporator defrosted?
Answer: Hot gas from the discharge line is sent to the evaporator after
the metering device.
⩥ Freon-12 has similar high and low pressures to what other refrigerant?
Answer: R-40, Methyl Chloride
,⩥ Evaporator -
1) If the pressure drop was less than 2.5 lbs., what would the system
have?
2) 2.5 lbs. but less then than 5 lbs.
3) 5 lbs. or more?
Answer: 1. Nothing
2. External equalizer
3. Multicircuit system
⩥ Oil safety switch
1) Operating pressure _____?
2) 2 pressures __.__
3) Time delay __-__
4) Cuts off at _____.
Answer: 1) Operating pressure : 20 - 25 psi
2) Low side : oil pump
3) 90 - 120 second delay
4) Cuts off at 9 - 10 PSI (15?)
⩥ What is an open compressor?
Answer: An open compressor has an external drive.
,⩥ Thermostatic expansion valves are rated in
A) Superheat settings
B) Horsepower
C) Tons of refrigeration
D) All of the above
Answer: C) Tons of refrigeration
⩥ Low pressure control
Answer: Turns the compressor off at 30 PSI; turns on the compressor at
55 PSI.
⩥ In an efficiently operating induced draft cooling tower, the leaving
water is between:
Answer: Dry-bulb and wet-bulb temperature
⩥ When comparing a brine with a PH of 8 to one with a PH of 10—its
alkalinity is ___?
Answer: 100 times greater (ex. PH 8 to PH 9 is 10 times greater)
⩥ The most accurate of the following statements about compression
ratio of a reciprocating compressor is
A) It remains constant under all compressor operating conditions
, B) It varies according to the conditions under which the compressor
operates
C) It is the ratio of the suction pressure gauge to the discharge pressure
gauge
D) It equals the saturated discharge temperature divided by the saturated
suction temperature
Answer: B) It varies according to the conditions under which the
compressor operates
⩥ Which of the following is NOT a design factor affecting compressor
capacity?
A) Compressor speed
B) Clearance space
C) Piston displacement
D) Suction and discharge valve designs
Answer: A) Compressor speed
⩥ What would indicate a restriction, such as dirt, in the liquid line?
Answer: Frost immediately after the restriction
⩥ What does solubility mean?
Answer: The ability of a refrigerant to mix with other substances
