EPA 608 core

When a system is operating, refrigerant leaves the condenser as a ________.

C) high-pressure liquid

________ refrigerants are the most harmful to stratospheric ozone.

CFCs

What gas is used as the baseline measurement for GWP?

Carbon dioxide

Which health effect increases from loss of the stratospheric ozone layer?

Cases of cataracts and skin cancer

The Department of Transportation (DOT) requires ________ when transporting cylinders containing used refrigerant.

DOT classification tags

A reduction in stratospheric ozone causes ________.

Decreased crop yields and damage to marine organisms

Which appliances are NOT covered by EPA regulations?

Desiccant dehumidifiers

Which type of refrigerant typically has the lowest global warming potential?

HFOs

HCFC refrigerants are made up of ________.

Hydrogen, chlorine, fluorine, and carbon

HFC refrigerants contain ________.

Hydrogen, fluorine, and carbon

An oil sample should be taken for which of the following reasons?

Moisture or acid is suspected.

HFO refrigerants are miscible in ________ lubricants.

POE lubricants

Which synthetic oil is commonly used with HFC refrigerants?

Polyolester (POE)

An example of an HCFC refrigerant is:

R-123

Which refrigerant is considered a low-pressure refrigerant?

R-123

Which refrigerants is an HFO?

R-1234yf

Which refrigerant is an HFC?

R-134a

________ contains chlorine.

R-22

________ refrigerant has an ODP that is greater than 0.

R-22

Which refrigerant can fractionate?

R-407C

Which refrigerant is considered a high-pressure refrigerant?

R-410A

________ has the lowest ODP.

R-410A

Which of the following refrigerants has the lowest global warming potential?

R-600a

________ returns refrigerant to new product specifications and requires chemical analysis to verify the purity to AHRI-700 standards.

Reclaiming

How should disposable cylinders be discarded?

Recover all remaining refrigerant, render the cylinders useless, and recycle the metal

What does NOT require Section 608 certification?

Rewiring a condenser fan

Which material is NOT compatible with any HFO refrigerant?

Silicone

Which of the following gases help form the earth's protective shield?

Stratospheric ozone

________ means that the refrigerant blend has a range of bubble or dew points at a constant pressure.

Temperature glide

How does the GWP of R-410A compare to carbon dioxide?

The GWP of R-410A is thousands of times greater.

The pressure range that is typically displayed on a high-pressure manifold gauge is ________.

0 to 800 psig

According to the Roland-Molina theory, ________ are destroyed by each chlorine atom in the stratosphere.

100,000 ozone molecules

An oil sample might be taken when ________. -- Answer is D

A) moisture and/or acid problems are suspected B) oil sludge formation or oil waxing is suspected C) residual acidic oil from a burn-out is suspected of contaminating the replacement oil D) all of the above

The Montreal Protocol is ________.

An international treaty that addresses ozone-depleting substances and their alternatives

The capacity of a vacuum pump and its suction line size affect ________.

moisture removal and evacuation time

Ozone contains ________.

molecules containing 3 oxygen atoms

Over-evacuation of a system can ________.

never occur; you can never pull too much air or other impurities from a system

Ester-based oils like POE can be mixed with ________.

no other oils

Department of Transportation (DOT) regulations require the ________ to be recorded on the shipping paper for hazard class 2.2 Nonflammable Compressed Gases.

number of cylinders of each gas

In refrigerant accidents where death occurs, the major cause is ________.

oxygen deprivation

If R-410A was added to an R-22 system, ________.

recover the mixture in a separate recovery tank

When a system is operating, the ________ changes a low-pressure vapor to a high-pressure vapor.

compressor

When a system is operating, the ________ changes the refrigerant from a high-pressure vapor to a high-pressure liquid?

condenser

If a system cannot maintain a vacuum, the system ________.

could have a leak or still be evaporating off trapped refrigerant or moisture

A refrigerant label is placed on the ________.

cylinder to identify the refrigerant

When transferring liquid in service hoses, you should guard against trapping ________.

liquid refrigerant in the service hose between closed service valves

After proper R-410A refrigerant recovery, you should use ________ to leak check the system.

nitrogen, and if a trace gas is desired, add a small amount of R-410A

If the compressor crankcase is the coldest part of the system, refrigerant will migrate to the compressor because of the difference in ________ in the system.

pressure

Before shipping any recovered refrigerant, you must ________.

properly label the refrigerant container

Before disposing of any appliance containing refrigerant ________.

recover the refrigerant

After a refrigerant is phased-out, supplies of that refrigerant for equipment servicing can only come from ________.

recovered and reclaimed refrigerant

A system containing a flammable refrigerant must have the process tubes marked with a ________ color

red

The stratospheric ozone layer protects us from ________.

ultraviolet radiation from the sun

Always measure the final system vacuum ________.

with the system isolated from the vacuum pump

What is being done in the U.S. to stop damage to the stratospheric ozone layer?

Eliminating the use of CFCs and HCFCs refrigerants

which refrigerant can be purchased is you have EPA's section 608 certification

Only refrigerants that are exempt from the venting prohibition

Which refrigerant depletes the ozone layer?

R-22

Approved refrigerant recovery cylinders have ________.

Yellow tops and gray bodies

When a system is operating, refrigerant enters the expansion device as a ________

subcooled or saturated liquid

Never heat a recovery tank with an open flame because ________.

the high temperature can cause the pressure relief valve to vent, the tank to explode, or the refrigerant to decompose

Recovery cylinders should never be overfilled because ________.

the internal pressure of the cylinders can rise in heated areas and cause an explosion or venting

Use ________ to determine a safe pressure for leak testing.

the value on the low-side test pressure data plate

The release of any CFC, HCFC, or HFC refrigerant during ________ is illegal.

theft of equipment

Non-toxic refrigerants can still cause death because ________.

they are heavier than air and can cause asphyxia

A ternary blend refrigerant is a ________.

three-part mixture

A system is evacuated ________.

to dehydrate the system

You heat a system during dehydration ________

to raise the vapor pressure of the water in the system and decrease dehydration time

When measuring a vacuum of the system, the vacuum gauge should be connected ________.

to the system as far as possible away from the vacuum pump

When a system using POE oil has been opened, what is the minimum evacuation level that should be achieved and held before charging the system?

500 microns

Which is NOT a "refrigerant" as it is used in EPA's regulations?

A leak trace gas.

Which additional safety precaution should be followed when using flammable refrigerants?--Answer is D both A and B

A) Always make certain the recovery tank and recovery unit are grounded before being used. B) Do not cut or weld any refrigerant line when refrigerant is in the unit. C) Never let the refrigerant hoses touch the ground. D) Both A and B

Which is a violation of EPA or Clean Air Act regulations? answer is D

A) Failing to evacuate refrigerant in a system to the required evacuation level B) Failing to evacuate refrigerant in a leaking system to at least 0 psig C) Adding nitrogen to a fully charged system, and then calling the mixture a "leak check gas" and venting the mixture to the atmosphere D) All of the above

Which is recommended after a burnout?--Answer is D

A) Install both a liquid line and suction line filter drier. B) Flush the system (not compressor) with a commercial system flushing solution. C) Purge with dry nitrogen before and after using the flushing solution. D) All of the above

Which of the following is classified as an A2L refrigerant?-- Answer is D

A) R-1234yf B) R-1234ze(E) C) R-32 D) All of the above are A2L refrigerants

How do scientists know that the chlorine in the stratosphere is not primarily from volcanoes?--Answer is D

A) The amounts of chlorine and fluorine are similar and fluorine does not come from volcanoes. B) The rise in chlorine levels in the stratosphere matches the rise in ozone-depleting emissions. C) Volcanic eruptions only produce a small quantity of chlorine. D) All of the above

When working with nitrogen, ________.--answer is D

A) always use a nitrogen regulator B) always have a pressure relief valve downstream of the regulator C) never use liquid nitrogen D) all of the above

Refrigerant cylinders should ________.-- answer is D

A) be free of rust and damage and have a valid pressure test marking B) never be filled to more than 80% of capacity C) always be labeled and secured in the vehicle D) all of the above

Before recharging any flammable hydrocarbon or HFO refrigerant, always ________.-- answer is D both A and B

A) electrically ground the recovery machine and recovery tank, and verify the refrigeration system is grounded B) install a fresh filter drier, successfully complete a standing-pressure leak check at the maximum system pressure, and then evacuate to at least 500 microns C) add the EPA-mandated odorant in case the system develops a leak D) both A and B

The fill level of a recovery cylinder can be determined by ________.--Answer is both A and B

A) mechanical-float or electronic shut-off devices B) the weight of the cylinder C) shaking the cylinder to determine if there is liquid inside D) both A and B

When planning to recovery flammable refrigerants, always ensure that ________.--Answer is D both B and C

A) the refrigerant is cooled first B) the recovery machine is rated for the refrigerant being recovered C) the recovery machine and the recovery tank are grounded D) both B and C

Always ________ when operating refrigerant recovery or recycling equipment.-- Answer is D

A) wear safety glasses B) wear protective gloves C) follow all safety precautions (for the equipment) D) all of the above

What are the characteristics of hydrofluoroolefins and hydrocarbon refrigerants?

0 ODP and low GWP

EPA recommends this service practice to conserve refrigerant.

Find and repair leaks in the system.

________ damages stratospheric ozone.

HCFCs

Which of the following proves that HCFCs are in the stratosphere?

HCFCs found in air samples from the stratosphere.

What provides the cooling in a vapor compression refrigeration system?

The vaporization of the liquid refrigerant.

Why are flammable HFO refrigerants classified as A2L and not A2?

They have low flammability, being less flammable than HC refrigerants.

________ to verify the allowable machine test pressure.

Use the value on the system nameplate

Which refrigerant release is illegal?

Venting refrigerant from an approved dual-refrigerant recovery machine to switch working fluids.

Azeotropic refrigerant mixtures ________.

act like a single-component refrigerant and can be charged as either a liquid or vapor

According to the EPA, ________ should be used to remove ice from a sight glass.

an alcohol spray

The service hose between the system and the vacuum pump should ________.

be as short as possible

The low-pressure gauge on a typical gauge manifold set is colored ________.

blue

A flammable refrigerant can only burn or explode if the refrigerant concentration is ________.

both above the lower flammability limit and below the upper flammability limit

Long hoses between the unit and the recovery machine ________.

can cause excessive pressure drop and increased recovery time

State and local governments ________.

can make laws that are stricter requirements than the federal regulations

What refrigerant servicing does NOT require Section 608 certification?

carbon dioxide refrigerant

EPA regulations only allow recovered or recycled refrigerant to be ________.

charged into the same or another appliance owned by the same person

CFCs and HCFCs ________making them capable of reaching the stratospheric ozone layer.

do not dissolve in water or easily break down in the atmosphere.

The EPA considers ________ the most effective for locating the general area of a small leak.

electronic or ultrasonic tester