FDNY z51 Test
What is a superheated vapor? completely dry vapor
In electrical circuits the conductor is always what color? Green or Bare
Unloaders are used for what? To increase capacity
Oil foaming in a crankcase is caused by what? A sudden drop in crankcase pressure
How would you test for acid in the refrigerant? Spraying liquid refrigerant from a condenser or receiver on to bond paper
What is the function of a cylinder bypass? To allow operation at different capacities
The chilled water supply to the building is 55F. If the Yes. this temperature is too high for human comfort purpose
chiller is being used for human comfort, should you be
concerned about this, and why?
The packing gland of a centrifugal pump serves to: The drip part of the packing gland gives evidence that there is water in the pump
Capacity control of a reciprocating hermetic compressor Operation of the hot gas bypass valve
is typically achieved through
The most important reason to sub-cool the refrigerant in A pure liquid refrigerant will enter the metering device
the condenser is to ensure that:
A refrigeration engineer is logging reading from a An expansion valve that is open to wide
reciprocating system. compressor discharge temperature
have dropped significantly and the suction line pressure
is high. which of the following that may be causing this
set of condition.
A low side float valve is used to maintain: The level of the refrigerant in the evaporator
Regarding fire safety, which ASHRAE refrigerant safety A1
classification indicates no flammability and lower
toxicity?
All liquid has been recovered from a system to be Should not be opened until all vapor has been recovered
overhauled, the system
When a refrigerant engineer uses a portable compressor The vapor density is decreasing
recovery unit to remove vapor refrigerant from a
refrigeration system the removal rate of the refrigerant
will gradually slow down because
, FDNY z51 Test
You are the engineer running a 2000-ton (steam-driven Add additional make up water to cooling tower
turbine) centrifugal refrigeration system, a refrigeration
system supplies chilled water to a college campus with
multiple buildings. During the course of making your
rounds, you check the 9 cell cooling tower on the roof.
You note the water level in all of the cooling tower cells is
very low. Which one of the following immediate action
would take?
A rooftop water cooling tower is connected to a water 323
pump in the building basement with a 12 inches diameter
pipe, with the pump turn off, a pressure gauge at the
pumps inlet show a pressure of 140 PSIG the height of
the water column, in feet, would be closet to.
What device protects the steam turbine from excessive Governor assembly
speed?
A refrigeration compressor has failed to turn on. The Temperature and pressure controls
refrigeration engineer on duty verifies that the electrical
circuit to the motor, including all switches and circuit
breakers, is complete according to recommended
service practice, the next item to be checked would likely
be the:
Refrigerants are characterized by their physical Ammonia
properties included flashpoint, refrigeration effect, and
others. Of the refrigerants in commercial and industrial
the highest latent heat and refrigerant effect is:
On what characteristics is ASHRAE refrigerant safety flammability and toxicity
group classification system:
Of the following, and example of an in-line refrigerant Refrigerant recycling
cleaning system that may be used with a centrifugal
compressor containing R123 refrigerant is:
Information about the physical and chemical properties Material Safety Data Sheet
of a hazardous material can be found in:
What is the function of the turbine auxiliary oil pump? Establish oil pressure during turbine start up
The rupture disc for a low-pressure centrifugal Compressor suction
refrigeration machine is normally located on the:
What is the primary reason ribbed metal piping is used It allows for flexibility and accounts for vibrations
for electrical wires connected to the refrigeration system
shown below?
The most important reason to use at least two Avoid very high compression ratio for each compressor
compressors in a cascade system is to:
The suction service valve of a reciprocating compressor Malfunction of a compressor valve
is front seated and the compressor runs until the low
pressure cut-out shut the compressor off. When the
machine is stopped, the refrigeration engineer notices
that the suction pressure increase rapidly. The most
probable cause of this pressure rise:
What is a superheated vapor? completely dry vapor
In electrical circuits the conductor is always what color? Green or Bare
Unloaders are used for what? To increase capacity
Oil foaming in a crankcase is caused by what? A sudden drop in crankcase pressure
How would you test for acid in the refrigerant? Spraying liquid refrigerant from a condenser or receiver on to bond paper
What is the function of a cylinder bypass? To allow operation at different capacities
The chilled water supply to the building is 55F. If the Yes. this temperature is too high for human comfort purpose
chiller is being used for human comfort, should you be
concerned about this, and why?
The packing gland of a centrifugal pump serves to: The drip part of the packing gland gives evidence that there is water in the pump
Capacity control of a reciprocating hermetic compressor Operation of the hot gas bypass valve
is typically achieved through
The most important reason to sub-cool the refrigerant in A pure liquid refrigerant will enter the metering device
the condenser is to ensure that:
A refrigeration engineer is logging reading from a An expansion valve that is open to wide
reciprocating system. compressor discharge temperature
have dropped significantly and the suction line pressure
is high. which of the following that may be causing this
set of condition.
A low side float valve is used to maintain: The level of the refrigerant in the evaporator
Regarding fire safety, which ASHRAE refrigerant safety A1
classification indicates no flammability and lower
toxicity?
All liquid has been recovered from a system to be Should not be opened until all vapor has been recovered
overhauled, the system
When a refrigerant engineer uses a portable compressor The vapor density is decreasing
recovery unit to remove vapor refrigerant from a
refrigeration system the removal rate of the refrigerant
will gradually slow down because
, FDNY z51 Test
You are the engineer running a 2000-ton (steam-driven Add additional make up water to cooling tower
turbine) centrifugal refrigeration system, a refrigeration
system supplies chilled water to a college campus with
multiple buildings. During the course of making your
rounds, you check the 9 cell cooling tower on the roof.
You note the water level in all of the cooling tower cells is
very low. Which one of the following immediate action
would take?
A rooftop water cooling tower is connected to a water 323
pump in the building basement with a 12 inches diameter
pipe, with the pump turn off, a pressure gauge at the
pumps inlet show a pressure of 140 PSIG the height of
the water column, in feet, would be closet to.
What device protects the steam turbine from excessive Governor assembly
speed?
A refrigeration compressor has failed to turn on. The Temperature and pressure controls
refrigeration engineer on duty verifies that the electrical
circuit to the motor, including all switches and circuit
breakers, is complete according to recommended
service practice, the next item to be checked would likely
be the:
Refrigerants are characterized by their physical Ammonia
properties included flashpoint, refrigeration effect, and
others. Of the refrigerants in commercial and industrial
the highest latent heat and refrigerant effect is:
On what characteristics is ASHRAE refrigerant safety flammability and toxicity
group classification system:
Of the following, and example of an in-line refrigerant Refrigerant recycling
cleaning system that may be used with a centrifugal
compressor containing R123 refrigerant is:
Information about the physical and chemical properties Material Safety Data Sheet
of a hazardous material can be found in:
What is the function of the turbine auxiliary oil pump? Establish oil pressure during turbine start up
The rupture disc for a low-pressure centrifugal Compressor suction
refrigeration machine is normally located on the:
What is the primary reason ribbed metal piping is used It allows for flexibility and accounts for vibrations
for electrical wires connected to the refrigeration system
shown below?
The most important reason to use at least two Avoid very high compression ratio for each compressor
compressors in a cascade system is to:
The suction service valve of a reciprocating compressor Malfunction of a compressor valve
is front seated and the compressor runs until the low
pressure cut-out shut the compressor off. When the
machine is stopped, the refrigeration engineer notices
that the suction pressure increase rapidly. The most
probable cause of this pressure rise:
