Written Z51 Questions And Answers Latest Top Score.
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Written Z51 Questions And Answers Latest Top Score.
The efficiency of the refrigerant cycle is affected by the operation of the condenser. of the following. a more efficient centrifugal compressor operation results from: - correct answer. Lowering the condensing pressure
The heat remov...
Written Z51 Questions And Answers Latest Top
Score.
The efficiency of the refrigerant cycle is affected by the operation of the condenser. of
the following. a more efficient centrifugal compressor operation results from: - correct
answer. Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is: - correct answer. Sensible
and latent heat
The refrigerant unit that you have been assigned to is being taken out of service for a
major repair. you have been assigned to withdraw refrigerant for storage in suitable
containers. according to the new York city fire code, you must ensure that the
containers: - correct answer. Are approved by the US department of transportation
Which of the following best describes how the cylinder unloader work? - correct answer.
Keep in the suction valve opened while the compressor is in the return stroke
In most semi hermetic compressors, the suction vapor is used to: - correct answer.
Cool the motor
The amount of refrigerant that flows through the orifices of a economizer is determined
by the: - correct answer. Difference between the high side and load side pressure
The installation of an inline refrigerant cleaning system is advisable: - correct answer.
To remove impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the building
space that are cooled - correct answer. The indirect system
The suction pressure of a reciprocating compressor is 65PSIG. the discharge pressure
of this compressor is 120PSIG. the atmospheric is 14.7 PSI. the compression ratio for
the given condition is closet to: - correct answer. 1.69
A super heated vapor is a ? - correct answer. Dry vapor above the saturation
temperature
A refrigerant engineer verifies that a condenser water pump is cavitating. of the
following the most likely cause for this condition is: - correct answer. A faulty cooling
tower water level controller
A centrifugal water pump is known as a lift pump when the: - correct answer. The
water supply to the pump suction inlet is below the pump level
,A TXV is used to maintain constant: - correct answer. Evaporator superheat
The chilled water supply to the building is 55F. if the chiller is being used for human
comfort, should you be concerned about this , and why? - correct answer. Yes, this
temperature is too high for human comfort purpose
The packing gland of a centrifugal pump serves to: - correct answer. The drip part of
the packing gland gives evidence that there is water in the pump
Capacity control of a reciprocating hermetic compressor is typically achieved through -
correct answer. Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that:
- correct answer. A pure liquid refrigerant will enter the metering device
A refrigeration engineer is logging reading from a 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. - correct answer. An
expansion valve that is open to wide
A low side float valve is used to maintain: - correct answer. The level of the refrigerant
in the evaporator
Regarding fire safety, which ASHARE refrigerant safety classification indicates no
flammability and lower the toxicity? - correct answer. A1
When an expansion valve is operating properly, at the end of the evaporator will
contain: - correct answer. Only superheated vapor
What information is not contained in a material safety data sheet-MSDS? - correct
answer. Cost of material
In a steam turbine, what is the function of the kingsbury thrust bearing - correct answer.
Maintain axial positioning of the rotor shaft
A centrifugal water pump is considered to be fully primed when - correct answer. The
pump is full of liquid
Copper tubing refrigerant lines must be installed for a new system. it is a well known
service practice that tubing collapses at bends that must be made, the refrigerant
engineer should use - correct answer. Lever type tubing bender
A reciprocating compressor is making a knocking sound during operation. if the
refrigerant worn parts are not causing the knocking, what is probably the cause - correct
answer. The slugging of the liquid refrigerant
, In order for a refrigerant to become superheated in a section of the lowside refrigerant
line: - correct answer. Where no liquid refrigerant is present
All liquid has been recovered from a system to be overhauled, the system - correct
answer. Should not be opened until all vapor has been removed
When a refrigerant engineer uses a portable compressor recovery unit to remove vapor
refrigerant from a refrigeration system the removal rate of the refrigerant will gradually
slow down because - correct answer. The vapor density is decreasing
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. 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? - correct answer. Add additional
make up water to cooling tower
A rooftop water cooling tower is connected to a water 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. - correct answer. 323
What device protects the steam turbine from excessive speed? - correct answer.
governor assembly
A refrigeration compressor has failed to turn on. the 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: - correct answer. Temperature and pressure controls
Refrigerants are characterized by their physical properties included flash point,
refrigeration effect, and others. of the refrigerant in commercial and industrial the
highest latent hear and refrigerant effect is: - correct answer. Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system: -
correct answer. Flammability and toxicity
Of the following, and example of an in-line refrigerant cleaning system that may be used
with a centrifugal compressor containing R123 refrigerant is: - correct answer.
Refrigerant recycling
Information about the physical and chemical properties of a hazardous material can be
found in: - correct answer. Material Safety Data Sheet
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