RSI Phase 9 Final Review
The safety device that is used to start the compressor when excessively high head pressure develops is a _____________________________.
spring load relief valve
A type of strong tubing that is resistant to corrosion and commonly used for food processing, milk handling,and other refrigeration application is ________________ tubing.
stainless steel
The primary purpose of a liquid line in a commercial refrigeration system is to deliver a steady stream of high pressure ____________________.
subcooled liquid refrigerant
If a liquid line is not just warm, but noticeably hot, it probably contains _______________________________________.
super heated hot gas
To avoid overlooking details, a commercial refrigeration system should be inspected in a ________________ manner.
systematic
The position of a TXV's sensing bulb on the suction line depends on the _________.
tubing size
The best & most precise way to ensure a proper refrigerant charge is to _______________________.
weigh in the exact prescribed amount.
If the weight of the calculated daily ice production potential is within _______ of the manufacturers recommendations the machine is operating properly.
10%
To account for a refrigerant circuit that could become restricted, a commercial refrigeration systems liquid receiver should be sized _______ larger than the total liquid volume in the system.
15%
What is the superheat of a system with a suction line temperature of 52 degrees F, Low side pressure corresponding to 34 degrees F, and a liquid line temperature of 100 degrees F?
18 degrees F
The suction line should be sized so that the maximum pressure drop is equal to a saturation temperature drop of _____ F.
2 degrees
According to the US Department of Agriculture, hot foods must be cooled down to _________ after four hours.
41 degrees F
Per FDA requirements food storage equipment should maintain food temperature at or below _________ at all times.
41 degrees F
A standard single flare on copper tubing is made at a __________ angle.
45 degree
A refrigeration system is leak free if deep vacuum pressure holds steady around ____________.
500 microns
Tubing should always be cut at an angle of _________.
90 degrees
Packaged systems _______________.
All of the above
Which of the following variables should be checked before a technician decides what systems trouble is _____________________.
All of the above
Checking a systems refrigerant charge is important because an improper charge can ___________.
All of the above.
True of False: Fluid used in a secondary loop system changes phases just like traditional system refrigerants.
False
True or False: Adding liquid refrigerant directly into the liquid receiver is best done with the compressor running.
False
True or False: In all circumstances, bubbles in the liquid line indicate an insufficient charge in the system.
False
True or False: When performing and ice capacity check on an ice machine with a water cooled condenser the ambient air temperature should be measured and recorded.
False
Which of the following statements regarding an undercharged TXV system is false?
More heat than normal will be transferred to the high side.
When installing a new commercial system, a standing pressure test involves pressurizing the system with ____________ and letting it stand for 24 hours.
Nitrogen
Low temperature and medium temperature refrigeration systems used in trucks typically use __________ refrigerant.
R-404A
Which of the following statements regarding pump down or removal of refrigeration is false?
Refrigerant removal requires bringing the system into high-pressure to evaporate the refrigerant from the section being dismantled.
How does ambient temperature affect the amount of heat an air-cooled condenser can reject?
The higher the ambient temperature, the less heat it can reject.
Which of the following statements regarding system pump down is false?
The liquid receiver service valve must remain in mid position while the compressor is running.
True or False: There should not be a measurable difference in pressure measurements taken before and after the filter drier.
True
A starved evaporator would likely be caused by the following problems except for _________________________.
a TXV's sensing bulb not being in contact with the suction line.
The main task of a drier is to _______________________________________________________.
absorb moisture and other contaminants that could mix to create acids.
When oil has been removed from a compressor, it should be tested for _________________________.
acidity and contamination
Super heat may be described as the amount of heat __________________________________.
added to the refrigerant after it has evaporated
The thickness of ice cubes formed in a vertical evaporator ice machine is reduced by _______________________________________.
adjusting the ice thickness sensor
The most common non-condensable that gets trapped in the system is __________.
air
After pumping down a refrigeration system for the purpose of removing an expansion valve, it would make the most sense for a technician to close _________________________________.
all suction line manifold valves
A type of tubing commonly used to form evaporators and is less costly than copper is __________ tubing.
aluminum
For a large split commercial refrigeration system a condensing unit should be ________________________ the conditioned space.
as close as possible to
A liquid receiver service valve is in the _________ position to finish charging with compressor on.
back seated
When using an external spring to bend soft ACR tubeing that will be connected to a flare connector, remember to _______________________________________.
bend the tube before flaring
A system specifically designed to reduce the temperature of cooked food to frozen storage temperature is a _______________________.
blast freezer
The primary danger of acidity to a hermetic compressor is ______________.
breakdown of winding insulation
If a liquid line filter drier is clogged and restricted in some way, _____________ will appear in the site glass
bubbles
When servicing a system that had a hermetic compressor that burned out, be certain to install _________________________ after triple evacuation.
burnout filter driers in the suction and liquid lines
Dry ice is composed of frozen solid __________________.
carbon dioxide
The degree of super heat is the difference between the refrigerants evaporating temperature and the temperature of the vapor at the __________ inlet.
compressor
If a filter drier is clogged it will feel _________________.
cooler than normal
a technician that suspects that refrigerant is leaking into the water circuit of a water-cooled condenser should confirm such a suspicion on a _____________________________.
electronic leak detector
In a multiple evaporator system, a(n) ______________________ should be included between the suction line manifold and outlet of the warmest evaporator.
evaporator pressure regulator
If a technician inspecting a multiple evaporator refrigeration compared two pressure measurements (one taken from an evaporator with an EPR and another taken from an evaporator without an EPR), most likely the ___________________________________________________________________.
evaporator with an EPR would have a higher pressure measurement
In a commercial refrigeration system a sight glass should be installed between the ____________.
filter-drier and the metering device
Checking refrigerant charge by super heat is normally done on system using _____________.
fixed orifice metering devices
The refrigerant that immediately vaporizes as it passes through the metering device is referred to as _________.
flash gas
When a technician determines that an ice machines condenser water circuit has a thin layer of mineral deposits, the technician should ________________.
flush the water circuit with a scale remover
Relief valves are generally used to protect against high _____________.
head pressure
A refrigeration system with a restriction in its capillary tube is likely to exhibit __________________________.
high super heat
An ice machine with a vertical cube evaporator sensor will switch from refrigeration cycle to harvest cycle by using a(n) ______________________________________.
ice thickness sensor
in commercial refrigeration, an air curtain is used to __________________________________.
isolate a conditioned space.
The primary purpose of evaporator pressure regulators on a multiple evaporator system is to _____________________.
maintain different evaporator temperatures.
When there is a very light and steady load and only a small amount of heat to move in a multiple compressor system, then ________________.
only one compressor runs
A system specifically designed to reduce the temperature of cooked food to refrigerated storage temperature is a __________________.
quick chiller
After tubing is cut, burrs on the cut end should be removed by __________________.
reaming
Sub cooling may be described as the amount of heat __________.
removed from a refrigerant after it has condensed
A substance in vapor form that is in the presence of some of its own liquid is a _________________ vapor.
saturated
