FDNY Z51 RMO QUESTIONS & ANSWERS
110. Water and moisture is a serious problem in a refrigerant system, how to avoid:
A. Use of fins in refrigerant line
B. Proper evacuation at the charging of the system
C. Proper handling of refrigerant and oil to avoid exposure to mixture
D. Use of high viscosity oil in the connection - Answers- B. Proper evacuation at the
charging of the
system
111. The most important requirements for a good evaporator is that:
A. Air or liquid refrigerant can be used as required by the medium being cooled
B. It must have enough cooling surface to absorb the required heat.
C. Operates only when the heat load exceeds a minimum
D. The refrigerant is contained in tubes - Answers- B. It must have enough cooling
surface to absorb the required heat.
112. While on duty a refrigeration engineer notices that the suction line to the
compressor and part of the compressor itself is frosted of the following, the most likely
reason for this condition would be:
A. Low condenser water temperature
B. The TEV is almost closed
C. There is a blockage in the liquid line
D. There is not enough refrigerant in the system - Answers- D. There is not enough
refrigerant in the system
113. While doing a routine line inspection, the engineer notices the bulb of the TXV on
the floor. The refrigerant engineer should attach bulb at the:
A. Three quarters way towards the end of the coil.
B. The inlet end of the coil
C. The expansion valve outlet
D. The outlet end of the coil - Answers- D. The outlet end of the coil
114. To convert water at 32F to ice at the same temperature a refrigeration system must
remove:
A. Latent heat of vaporization
B. The heat of crystallization
C. Sensibility heat
D. The latent heat of fusion - Answers- D. The latent heat of fusion
,115. The use of oil in the refrigeration machine is to:
A. Mix the oil with liquid refrigerant
B. Add non condensables to refrigerant
C. Reduce wear and friction in the compressor parts
D. None of the above - Answers- C. Reduce wear and friction in the compressor parts
120. A refrigerant engineers was instructed to charge of 60 ton plant with R134A
Refrigerant. The refrigerant engineer will most likely find the charging valve on the
A. Discharge side of the compressor
B. Receiver
C. High side pressure side of the system
D. Low pressure side of the system - Answers- D. Low pressure side of the system
121. A refrigerant engineer verifies that a chilled water pump is cavitating. Of the
following the most likely cause for this condition is:
A. A faulty cooling tower water level controller
B. Operating at sustaining high loads
C. Too long a period between pump servicing
D. Water leaks through the mechanical seals - Answers- D. Water leaks through the
mechanical seals
122. There is a decrease in the efficiency of a reciprocating compressor. This is mostly
likely caused by:
A. High suction pressure
C. Low suction pressure
B. Leaking suction valve
D. Leaking discharge line - Answers- B. Leaking suction valve
123. The suction and discharge valve of the reciprocating compressor are mounted as
follows:
A. Suction and discharge valve on the upper side of the plate
B. Suction and discharge valve below the valve plate
C. Discharge valves below the valve plate and suction valve above it
D. Discharge valve on top of the valve plate and suction valve below. - Answers- D.
Discharge valve on top of the valve plate and suction valve below.
124. You are the engineer running a 2000 ton (steam-driven turbine) centrifugal
refrigeration system, a refrigeration system supplies chilled water to a college campus
with multiple buildings. While making your rounds you notice that the discharge
pressure of your condenser water pumps is significantly lower than the normal. Which
following action would you avoid taking:
, A. Put on a addition condenser water pump
B. Flush out the bucket strainer of the condenser water pump.
C. Send you assistant to check for cooling tower level
D. Put on an additional surface condenser pump and lower the chilled water set point. -
Answers- D. Put on an additional surface condenser pump and lower the chilled water
set point.
125. A water pump is discharge against head 92 feet of water, this is approximately to a
pressure of:
A. 95 psi
B. 20 psi
C. 40 psi
D. 180.psi - Answers- C. 40 psi
126. Which one of the following will connect to the middle port on a gauge manifold?
A. Solenoid valve
B. King valve
C. Vacuum pump
D. Suction or discharge service valves - Answers- C. Vacuum pump
127. The most important reason for installing a muffler in reciprocating refrigerant
machine is:
A. Prevent compressor damage
B. Prevent condenser damage
C. To contain the compressor pulsation noise
D. To reduce velocity of the refrigerant - Answers- C. To contain the compressor
pulsation noise
116. The following is a desirable property in a refrigeration
A. High corresponding operation pressure
B. High viscosity
C. High latent heat
D. High corresponding compressor discharge temperature - Answers- C. High latent
heat
117. The cooling medium for an evaporative condenser is:
A. Air B. Air and water C. Water D. Condenser fan - Answers- B. Air and water
118. The ratio of the actual pressure of water vapor in the
atmosphere to the saturated pressure of give temperature is:
110. Water and moisture is a serious problem in a refrigerant system, how to avoid:
A. Use of fins in refrigerant line
B. Proper evacuation at the charging of the system
C. Proper handling of refrigerant and oil to avoid exposure to mixture
D. Use of high viscosity oil in the connection - Answers- B. Proper evacuation at the
charging of the
system
111. The most important requirements for a good evaporator is that:
A. Air or liquid refrigerant can be used as required by the medium being cooled
B. It must have enough cooling surface to absorb the required heat.
C. Operates only when the heat load exceeds a minimum
D. The refrigerant is contained in tubes - Answers- B. It must have enough cooling
surface to absorb the required heat.
112. While on duty a refrigeration engineer notices that the suction line to the
compressor and part of the compressor itself is frosted of the following, the most likely
reason for this condition would be:
A. Low condenser water temperature
B. The TEV is almost closed
C. There is a blockage in the liquid line
D. There is not enough refrigerant in the system - Answers- D. There is not enough
refrigerant in the system
113. While doing a routine line inspection, the engineer notices the bulb of the TXV on
the floor. The refrigerant engineer should attach bulb at the:
A. Three quarters way towards the end of the coil.
B. The inlet end of the coil
C. The expansion valve outlet
D. The outlet end of the coil - Answers- D. The outlet end of the coil
114. To convert water at 32F to ice at the same temperature a refrigeration system must
remove:
A. Latent heat of vaporization
B. The heat of crystallization
C. Sensibility heat
D. The latent heat of fusion - Answers- D. The latent heat of fusion
,115. The use of oil in the refrigeration machine is to:
A. Mix the oil with liquid refrigerant
B. Add non condensables to refrigerant
C. Reduce wear and friction in the compressor parts
D. None of the above - Answers- C. Reduce wear and friction in the compressor parts
120. A refrigerant engineers was instructed to charge of 60 ton plant with R134A
Refrigerant. The refrigerant engineer will most likely find the charging valve on the
A. Discharge side of the compressor
B. Receiver
C. High side pressure side of the system
D. Low pressure side of the system - Answers- D. Low pressure side of the system
121. A refrigerant engineer verifies that a chilled water pump is cavitating. Of the
following the most likely cause for this condition is:
A. A faulty cooling tower water level controller
B. Operating at sustaining high loads
C. Too long a period between pump servicing
D. Water leaks through the mechanical seals - Answers- D. Water leaks through the
mechanical seals
122. There is a decrease in the efficiency of a reciprocating compressor. This is mostly
likely caused by:
A. High suction pressure
C. Low suction pressure
B. Leaking suction valve
D. Leaking discharge line - Answers- B. Leaking suction valve
123. The suction and discharge valve of the reciprocating compressor are mounted as
follows:
A. Suction and discharge valve on the upper side of the plate
B. Suction and discharge valve below the valve plate
C. Discharge valves below the valve plate and suction valve above it
D. Discharge valve on top of the valve plate and suction valve below. - Answers- D.
Discharge valve on top of the valve plate and suction valve below.
124. You are the engineer running a 2000 ton (steam-driven turbine) centrifugal
refrigeration system, a refrigeration system supplies chilled water to a college campus
with multiple buildings. While making your rounds you notice that the discharge
pressure of your condenser water pumps is significantly lower than the normal. Which
following action would you avoid taking:
, A. Put on a addition condenser water pump
B. Flush out the bucket strainer of the condenser water pump.
C. Send you assistant to check for cooling tower level
D. Put on an additional surface condenser pump and lower the chilled water set point. -
Answers- D. Put on an additional surface condenser pump and lower the chilled water
set point.
125. A water pump is discharge against head 92 feet of water, this is approximately to a
pressure of:
A. 95 psi
B. 20 psi
C. 40 psi
D. 180.psi - Answers- C. 40 psi
126. Which one of the following will connect to the middle port on a gauge manifold?
A. Solenoid valve
B. King valve
C. Vacuum pump
D. Suction or discharge service valves - Answers- C. Vacuum pump
127. The most important reason for installing a muffler in reciprocating refrigerant
machine is:
A. Prevent compressor damage
B. Prevent condenser damage
C. To contain the compressor pulsation noise
D. To reduce velocity of the refrigerant - Answers- C. To contain the compressor
pulsation noise
116. The following is a desirable property in a refrigeration
A. High corresponding operation pressure
B. High viscosity
C. High latent heat
D. High corresponding compressor discharge temperature - Answers- C. High latent
heat
117. The cooling medium for an evaporative condenser is:
A. Air B. Air and water C. Water D. Condenser fan - Answers- B. Air and water
118. The ratio of the actual pressure of water vapor in the
atmosphere to the saturated pressure of give temperature is:
