DNY Z51 OR Z-51 REFRIGERATION EXAM NEWEST EXAM WITH 250 UPDATED QUESTIONS AND ANSWERS (VERIFIED ANSWERS) [ALREADY GRADED A+]
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Course
DNY Z51 OR Z-51 REFRIGERATION
Institution
DNY Z51 OR Z-51 REFRIGERATION
DNY Z51 OR Z-51 REFRIGERATION EXAM
NEWEST EXAM WITH 250
UPDATED QUESTIONS AND ANSWERS
(VERIFIED ANSWERS) [ALREADY GRADED
A+]
You are the engineer running a 2000-ton (steam-driven turbine)
centrifugal refrigeration system, a refrigeration system supplies
chilled water t o a college ca...
You are the engineer running a 2000-ton (steam-driven turbine)
centrifugal refrigeration system, a refrigeration system supplies
chilled water t o a college campus with multiple buildings.
making your rounds, you notice that condenser water pumptI is
making a lot of noise, the discharger gauge reading of the
condenser water pump is fluctuating drastically, and motor of the
condenser
pump #1 is running very hot. Which of the following actions would
youtake: - Turn on pump #2, shut of pumpf1, and trouble shot
pump #1
Electric devices may be used to provide built in defrosting of
refrigeration machineevaporator units. These devices are
classified as - Resistors
,2|Page
The flash point of compressorlubricating oil - Should be higher
than the compression temperature
The primary w a yof achieving capacity control of a
centrifugalcompressor is by; - Adjustment of the impeller inlet pre-
rotation vanes
Cooling tower water requiresthe addition of chemical additives in
order to: - Reduce the formation of scale and algae
In thepicture below describe the equipment'sfunction? - Remove
non condensable from the condenser
Theviscosity of lubrication oil isdescribed bya number. Alow
viscosity numberdescribes oil that - Flows easily
The most likely reason for a refrigeration engineer to use a
psychrometer is tomeasure - Relative humiditylevel of the
atmosphere
The most important reason tou s e at leastt w o compressors in a
cascade system is to - Avoid very high compression ratio for each
compressor
The suction service valve of areciprocating compressor is front
seated and the compressor runs
, 3|Page
until the low pressure cut-out shut thecompressor off. When the
machine is stopped, the
refrigeration engineernotices that the suction pressure increase
rapidly. The most probable cause of this pressure rise -
Malfunctionof acompressor valve
Regarding the functioning of a steam turbine,why is it advisablet o
keep moisture in theinlet low
as possible? - Keepsturbine blades wear tominimum
According to the attached Material Safety Data Sheet (MSDS)
R134 is a - Clear,odorless liquid and vapor
Under normal condition, the refrigerant enters the compressor as
a - Low pressure superheated vapor and leaves as a high
pressure vapor
While operating an R-22 single acting compressor system, the
refrigeration engineer noticed oil foaming in the crankcase. This
condition most likely, would have been caused by a - Sudden
drop in the crankcase pressure
Assume that an engineeris able to observe refrigerant water and
oiltogether. Thefluids would settle in thecontainerfrom top to
bottom: - Oil, water, refrigerant
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