Section 608 Core 91C002/003
Never use an open flame to heat a refrigerant tank because:
it can result in venting refrigerant to the atmosphere; the tank may explode, causing serious injury to people nearby; refrigerant in the tank may decompose, forming a toxic material.
The recovery of refrigerants is necessary to:
maintain adequate supplies for service calls after the production bans; prevent the venting of refrigerants to the atmosphere; prevent stratospheric ozone depletion
When using with any solvent, cleaner, chemical or refrigerant, you should review:
material safety data sheets.
What is the best proof that CFCs are in the stratosphere?
measurements of CFCs in air samples from the stratosphere
Systems charged with R-134a should be leak checked with:
pressurized nitrogen.
Systems charged with R-410A should be leak checked with:
pressurized nitrogen.
A compound pressure gauge, typically used on the low side of the system, measures pressure in:
psig and inches of mercury
Before you dispose of any system containing a refrigerant, you must:
recover the refrigerant.
A cylinder with a gray body and a yellow top indicates that the cylinder is designed to hold:
recovered refrigerant
During servicing of a refrigeration system containing R-12, the refrigerant must be:
recovered.
After 1995, any supplies of CFC refrigerants to service existing units in the USA can only come from:
recovery and recycling.
What effects can ozone depletion have on the environment?
reduced crop yields; reduced marine life; increased ground-level ozone
In a vapor compression refrigeration system, cooling occurs when:
refrigerant liquid turns to a vapor.
Which of the following refrigerant releases is a violation of the EPA prohibition on venting?
release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to "leak-check" the appliance.
A system is dehydrated to:
remove water and water vapor.
The EPA can require a technician to demonstrate their ability to perform proper procedures for recovering and/or recycling refrigerant. Failure to demonstrate competency can result in:
revocation of the technicians certification.
Recovery equipment that relies upon the compressor in the system would be considered:
system-dependent.
To determine the maximum allowable pressure to use when checking a system, check:
the design pressure on the equipment nameplate
Never overfill refrigerant storage cylinders because:
the internal pressure of the cylinders may rise in heated areas and cause an explosion.
It is important not to mix R-22 and R-410A refrigerants in the same container because:
the mixture may be impossible to reclaim.
It is important not to mix different refrigerants in the same container because:
the mixture may be impossible to reclaim.
Refrigerant that is recovered can be returned to:
the same system or other systems owned by the same person without restriction.
A system is considered dehydrated when:
the vacuum indicator shows you have reached and held the required finished vacuum.
A hermetic compressor must never be operated when:
there is a dehydration vacuum in the system.
Refrigerant vapors or mist should not be inhaled because
they may cause heart irregularities and/or unconsciousness.
A ternary refrigerant blend is a _______ part mixture.
three-part
The ozone layer protects the earth from:
ultraviolet radiation from the sun.
Refrigerant migrates to the compressor crankcase because of a difference in______between the refrigerant and the oil.
vapor pressure.
Disposable refrigerant containers are used for ______ refrigerant.
virgin.
Never use oxygen or compressed air to pressurize a system because:
when mixed with compressor oil or some refrigerants, it could explode.
According to the EPA, of the refrigerants liked below, which types of refrigerants will not contribute to Global Warming?
CFCs HCFCs HFCs all contribute to Global Warming
CFC refrigerants are so named because they contain the elements:
Chlorine, fluorine, carbon
Which safety precaution(s) should always be followed:
Never apply an open flame to a refrigerant cylinder; never cut or weld any refrigerant line when refrigerant is in the line; never use oxygen to purge lines or to pressurize a system.
It has been illegal to vent substitutes for CFC and HCFC refrigerants since:
November 1995
Which refrigerant is an HCFC?
R-123, R-124, R-22
Which refrigerant is an HCFC?
R-123, R-22, R-124
An example of an HFC refrigerant is:
R-134a
An example of an HCFC is:
R-22
Of the refrigerants listed below, which has the lowest ozone depletion potential (ODP)?
R-22
Which refrigerant contains an HCFC?
R-22
Which refrigerant is an HCFC?
R-22, R-123, R-124
An example of a HFC refrigerant is:
R-410A
An example of an HFC refrigerant is:
R-410A
_________is the process that returns refrigerant to new-product specifications and that requires chemical analysis?
Reclaim
______________refers to the process of cleaning refrigerant by oil separation and single or multiple passes through filter-driers, which reduce moisture and acidity?
Recycling
Manifold gauge sets are often color coded, when this is done, the high pressure gauge is color coded:
Red.
Which type of refrigerant is the most harmful to stratospheric ozone?
Refrigerants containing Bromine
What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
Refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere after being released. The chlorine or bromine reacts with the ozone, causing it to change back to oxygen, thus destroying the ozone layer.
Which of the following gases help form the earth's protective shield?
Stratospheric Ozone
Recovery equipment that relies upon the pressure of the refrigerant in the appliance would be considered:
System-dependent
Which atom of the CFC molecule causes ozone depletion?
chlorine
Which chemicals are controlled by the Montreal Protocol?
chlorofluorocarbons, hydrochlorofluorocarbons, halons
In a refrigerant system, the device that changes a low pressure vapor to a high pressure vapor is the:
compressor.
In a refrigeration system, high pressure vapor is converted to high pressure liquid in the:
condenser.
Non-azeotropic refrigerants leak from a system:
in uneven amounts due to different vapor pressures.
What is one of the most serious results of damage to the ozone layer?
increases in human skin cancer
Reusable refrigerant containers that are normally under any pressure above 15 pig must be hydrostatically tested and date stamped every:
5 Years
Ozone depletion potential, or "ODP," is:
A measure of the ability of CFCs and HCFCs to destroy ozone.
According to ASHRAE's 1992 refrigerant safety classification which of the following designations would be the most safe?
A-1
Which of the following is an approved "drop-in" service replacement for r-12?
According to the EPA there are no "drop-in" replacements
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least:
0 psig.
The high pressure gauge on service manifold sets has a continuous scale, usually calibrated to read from:
0 to 500 psi
An award of up to what amount may be paid to a person supplying information that leads to a penalty against a technician who is intentionally venting?
10,000
Each chlorine atom in the stratosphere can destroy____ozone molecules.
100,000
What statement is true about an azeotropic refrigerant mixture?
It is a mixture that acts like a single-component refrigerant over its entire range.
R-410A is not a typical blended refrigerant because:
It is near azeotropic refrigerant; it can be charged as either a liquid or vapor; while it has a 400 series refrigerant number it behaves like a 500 series refrigerant
Refrigeration technicians who violate the Clean Air Act can:
Lose their EPA certification, be fined, be required to appear in Federal court.
All devices used for a refrigerant recovery must:
Meet EPA standards
Data shows that chlorine in the stratosphere comes mainly from CFCs rather than from natural sources such as volcanoes because:
The rise in the amount of chlorine in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine; The rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions; Air samples taken from the stratosphere over erupting volcanoes show that volcanoes contribute a small quantity of chlorine to the stratosphere when compared to CFCs;
Whenever dry nitrogen from a portable cylinder is connected to a system, what item is of most importance in consideration of safety?
There is relief in the downstream line from the pressure regulator.
Chlorofluorocarbos (CFCs) and hydrochlorofluorocarbons (HCFCs) have which of the following in common?
They must be recovered before opening or disposing of appliances.
Technicians receiving a passing grade on the Type II (medium-pressure, high-pressure and very high pressure) exam are certified to recover refrigerant during the maintenance, service, or repair of medium- and high-pressure equipment and very high pressure refrigerants, including:
With Type II certification, you are certified for all very high pressure refrigerants including CFC-13 and CFC-503
When using recover unit, the fill level of the recovery tank can be controlled by:
a mechanical switch; an electronic shut-off device; weight
The Montreal Protocol is:
a treaty among nations that controls production of CFCs and HCFCs.
When transporting cylinders containing used refrigerant, the DOT requires that you:
attach DOT classification tags
Equipment covered by EPA regulations include:
all air-conditioning and refrigeration equipment using CFC, HCFC or HFC refrigerants.
Which refrigerant(s) must be recovered before opening a system or disposing of a system?
all refrigerants must be recovered.
Which of the following human health effects could result from an increase in ultraviolet radiation?
an increase in cataracts cases
HFC refrigerants:
are less harmful to stratospheric ozone than CFCs
In general, blended refrigerants should be charged:
as a liquid.
To obtain an accurate vacuum readings during system evacuation, the system vacuum gauge should be located:
as far from the vacuum pump as possible.
The proper method of discarding a disposable refrigerant cylinder is to:
assure that all refrigerant is recovered and that the cylinder is rendered useless, then recycle the metal.
Manifold gauge sets are often color coded, when this is done, the low pressure gauge is color coded:
blue.
"Self-contained" recovery devices:
can capture liquid and/or vapor refrigerant without the assistance of components in the air-conditioning or refrigeration equipment.
Even though R-22 is considered non-toxic, it:
can cause asphyxia.
When using nitrogen to pressurize a system, you should always:
charge though a pressure regulator.
The evacuation of a system is a method of:
dehydration.
The over-evacuation of a system:
does not occur.
Which gas(es) would cause the LEAST damage to the environment during a leak check?
dry nitrogen
According to the EPA, a_______ leak detection method is considered to be the most effective for locating the general area of a small leak.
electronic or ultrasonic tester
When evacuating a system, the hoses should be:
equal to or larger than vacuum pump inlet connection.
The type of oil that is most commonly used in stationary air conditioning applications with HFC-410A refrigerant is:
ester oil.
Long hoses between the unit and the recovery machine should not be used because they cause:
excessive pressure drop; increased recovery time; increased emissions
Violations of the Clean Air Act?
falsifying or failing to keep required records; failing to reach required evacuation levels before opening or disposing of appliances; knowingly releasing CFC or HCFC refrigerants or their substitutes while repairing appliances.
According to EPA regulations, which of the following is procedures is NOT an approved technique for system cleanup after a burnout?
flushing with liquid refrigerant to clean tubing
Refrigerant cylinders should always be:
free of rust and damage; color coded to indicate the contents; secure
PPE(gloves, safety glasses, safety shoes, etc.) should always be worn is when:
handling and filling refrigerant cylinders.
Refrigerant can not be called "reclaimed" unless it:
has been chemically analyzed and the refrigerant meets the ARI-700 standard.
HFC refrigerants contain:
hydrogen, fluorine, carbon
Blended refrigerants leak from a system:
in uneven amounts due to different vapor pressures.
