EPA Full Study Set

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

HFO's

How do the global warming potentials of isobutane (R-600a),propane (R-290), and R1441A compare to the GWPs of HFC-134a, R-404A, and R-410A?

They are significantly Lower

What are the characteristics of hydrofluoroolefins (HFOs)?

Non-ozone depleting, and have a low global warming potentials

Propane cylinders for grilling contain ___________ that can damagerefrigeration equipment

Impurities

Why are some hydrofluoroolefins (HFOs) classified as A2L?

They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable

Which of the following refrigerants has the lowest ozone depletion potential?

R-410A

R-22

R-123

R502

R-410A

What evidence demonstrates that chlorine in the stratosphere is primarily from man-made chemicals rather than from natural sources such as volcanoes?

A. The rise in the amount of chlorine measured in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine, over the same period.

B. The rise in the amount of chlorine measured in the stratosphere matches the rise in ODS emissions over the same period.

C. Samples of air taken from the stratosphere over erupting volcanoes show that volcanoes contribute a small quantity of chlorine to the stratosphere compared to CFCs and HCFCs.

D. All of the above.

All the above

As of 2017, how much can a technician be fined for violating the Clean Air Act, including knowingly releasing non-exempt refrigerant from appliances?

$44,539 per day per violation

After the phase-out of a refrigerant, where will supplies of thatrefrigerant for equipment servicing come from?

Recovery and reclaimed gas

Which of the following is illegal?

Knowingly releasing CFC, HCFC or HFC refrigerants during the service, maintenance, repair or disposal of appliances

When do EPA's refrigerant management regulations exempt refrigerantfrom the venting prohibition?

When you do not vent refrigerant in excess of the leak rate threshold

Which of the following statements about "self-contained" recovery devices istrue?

They remove refrigerant from an appliance without the assistance ofcomponents in the appliance

What can ester based oils be mixed with?

No other oils

What is the term used to describe the fact that a refrigerant blend has a range ofbubble or dew points at a constant pressure?

Temperature glide

Which word applies to the process that returns refrigerant to new product specifications and that requires chemical analysis?

Reclaim

If a system will not hold a vacuum after it has been evacuated what is theproblem?

It has a leak

How many different refrigerants may be recovered into the same cylinder?

Only 1

Vacuum lines (hoses) should be__________

Equal to or larger than pump intake connection

Upon completion of refrigerant liquid transfer between recovery unit and the refrigeration system, you should guard against trapping

Liquid refrigerant in the service hose between closed service valves

You should NEVER heat a refrigerant storage or recovery tankwith an open flame because

It can result in venting refrigerant to the atmosphere, The tankmay explode, causing serious injury to people nearby, andRefrigerant in the tank may decompose, forming a toxic gasses

Which of the following is NOT important to do before recharging any flammable hydrocarbon or HFO refrigerant into a system?

A. Ensure that the refrigeration system is electrically grounded.

B. Install a fresh filter-drier and successfully complete a standing- pressure leak check at the maximum system pressure.

C. Evacuate to 500 microns or lower.

D. Add an odorant to the system to indicate a flammable refrigerant is being used.

D. Add an odorant to the system to indicate a flammable refrigerant is being used.

All appliances must be equipped with a service aperture or process stub which is used when adding or removing refrigerant from the appliance. What is typically used on small appliances?

A straight piece of tubing that is entered using a piercing access valve

EPA Section 608 rules require capture of 80% of the HCFCs and HFCs from a small appliance sealed system with a non-operating compressor if technicians are using

A system-dependent (passive) process

The following does NOT meet the criteria for Type I appliance certification?

An MVAC-like system that holds three pounds of R-12 and split system AC containing 4 lbs ofR-22 only factory sealed systems such as water coolers, refrigerators/freezers and dehumidifiers

For which of the following refrigeration systems/appliances would it be permissible to use a passive recovery device for recovery of CFCs, HCFCs, and HFCs?

A. A centrifugal air conditioner

B. A reciprocating liquid chiller

C. A single compressor, large commercial walk-in freezer

D. A domestic refrigerator

D. A domestic refrigerator

What is the maximum normal charge of HCFC or HFC refrigerant in anappliance that is allowed to use system dependent recovery equipment?

15 lbs

What is the maximum allowable factory charge of refrigerant for Type Iappliances using CFCs, HCFCs, or HFCs?

5 lbs

What do you know about a refrigerant drop-in charge substitute?

There is no such thing as a "drop-in" substitute

New household refrigerators may be factory charged with any of the following refrigerants, EXCEPT

A.R-290

B. R-450A

C. R-600a

D. R-404A

D. R-404A

Which of the following refrigerants is very high pressure and generally does NOT need to be recovered?

A. R-22

B. R-134a

C. R-404A

D. R-744

D. R-744

After installing any type of access fitting onto a sealed system what must always be done before recovering any Refrigerant?

Leak Test the Fitting

When any refrigerant is recovered from an appliance the recovery vessel must be clearly marked to ensure that mixing of refrigerants does not occur

A standard vacuum pump designed specifically for evacuation and dehydration can

never be used as a recovery device in combination with a pressurized container

When is it essential to take measures to help release trapped CFC,HCFC, or HFC refrigerant from the compressor oil during refrigerantrecovery?

When using passive recovery devices on small appliances with non-operating compressors.

Which condition requires accessing both the high and low side of thesystem for refrigerant recovery when using the system-dependent(passive) recovery process?

When the compressor does not run

Why should low and high side access valves be installed whenrecovering refrigerant from a household refrigerator?

To improve speed of recovery

When using a self-contained recovery device on a CFC, HCFC, or HFC system with an operating compressor, technicians must

Either recover the refrigerant to 4 inches of mercury vacuum or 90%of the nameplate charge

What is the approximate pressure of a storage cylinder of recoveredR-134a that does not contain any non-condensable impurities and is stored in a room where the temperature is 80 F?

87 psig

Which of the following is an acceptable method or device presentlyused for monitoring the 80% fill level in a recovery tank?

Refrigerant scale or tank internal float device

Why should solderless type piercing valves NOT remain installed on refrigeration systems after completion of repairs?

They tend to leak over time

Which condition can cause excessive pressure on the high side of a self-contained (active) recovery device?

When there is a large volume of non-condensable gas in the refrigerant being recovered

Which of the following are recommended safe work practices when recovering refrigerants?

Wear safety eyewear and butyl-lined gloves when connecting/disconnecting hoses

Which of the following is required when attaching a gauge set to check system pressures?

Have manual or self-sealing valves on the ends of the gauge set hoses to minimize any release of refrigerant

If a large leak of refrigerant occurs such as from a filled cylinder in an enclosed area, what action should be takenwhen no self-contained breathing apparatus is available?

Vacate and naturally ventilate the area

A very large refrigerant leak can cause suffocation because refrigerants

Are heavier than air and displace oxygen

When first inspecting a hermetic system known to be leaking, you should look for

traces of oil

What should systems that use R-407C be leak checked with?

Pressurized nitrogen and a trace amount of R-22

To determine if the system is leaking more than the allowable rate, the EPA allows the use of which one of the following methods to determine the full charge?

Use of calculations based on component and pipe sizes

A company uses a chiller that diverts 55% of its cooling capacity to oneof its manufacturing lines and 45% of its cooling capacity to air conditionthe office spaces. Which leak rate category would this chiller be in?

Industrial process refrigeration

A cold storage warehouse chooses not to repair an appliance containing R-22 that is leaking above the threshold rate. How long can the facility continue to operate that appliance before it must be retrofitted or retired, assuming no extensions apply?

12 months

Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from an R-410A unit. What must be done before recovery?

Remove the R-22 from the recovery unit and change the filter

Recovered refrigerant may contain which of the following impurities?

Acids, moisture, and oil

What is the primary water source for a water cooled recovery unit's condensing coil?

Local municipal water supply

Refrigerant has been recovered from an air-conditioning system and held in a refillable cylinder, in order to replace the condenser coil. The refrigerant ______

may be charged back into the system

What steps should be taken before using a recovery unit to remove a charge?

The recovery' unit oil should be changed and recovery cylinder evacuated.

An operating unit that has a receiver/storage tank requires refrigerant system service. When servicing the unit

Refrigerant should be pumped down to and isolated in the receiver

How long must an HVAC servicing company keep records for each disposed appliance with a charge between 5 and 50 pounds?

3 years

Which of the following statements about recycling and recovery equipment usedfor stationary refrigeration is FALSE?

It must be tested by an EPA-approved third party

You are changing out the compressor of a system containing 40 pounds of R-404A. In addition to isolating the compressor, which of the following procedures should you follow?

Evacuate the isolated section of the system to 0 psig and if system pressure does not rise after a few minutes, remove the compressor

What should be done after reaching the required recovery vacuum on an appliance?

Wait for at least a few minutes to see if the system pressure rises

Before making a major repair, technicians must evacuate an appliance orcomponent containing more than 200 pounds of R-410A to which of thefollowing levels?

10 inches of Hg vacuum

When can appliances containing refrigerants be recovered toatmospheric pressure?

Leaks in the appliance make recovery to the prescribed levelunattainable

Which of the following repairs would always be considered "major"under EPA's regulations?

Replacement of an evaporator coil

When is it against EPA regulations to use system-dependent recoveryequipment?

When the appliance contains over 15 pounds of refrigerant

What is a deep vacuum usually measured in?

Microns

What will back-seating a suction shutoff valve close?

Gauge port

What is the approximate refrigerant pressure in an R-134arefrigerator, when it has been off for a long time and the room temperature has been maintained at 800 F

87 psig

When could a reciprocating compressor be damaged if energized?

When the discharge service valve is closed

It is best practice to use dry nitrogen to break the vacuum when dehydrating by the triple evacuation method. However, it requires a ______

pressure regulator

Pressure relief valves can only be installed

in parallel

Continuous excessive moisture collection in the purge unit of a low-pressure refrigeration system could indicate what condition?

The condenser or chiller barrel tubes are leaking

Which component is particularly susceptible to leaks in low-pressure refrigeration systems with open drive type compressors?

Shaft seal

Excessive running of a purge system on a low-pressure chiller generally indicates what condition?

Leaking system

According to ASHRAE Guideline 3, the system should be checked forleaks if during a standard vacuum test the pressure in a system risesfrom 1 mm Hg to a level above

2.5 mm Hg

Which of the following is NOT required for an appliance that is using an ozone-depleting refrigerant to be mothballed (thereby extending the leak repair deadline)?

Evacuate refrigerant from the appliance to at least atmospheric pressure

Starting in 2019, what is the leak rate threshold for commercial refrigerationequipment with a full charge of 50 or more pounds of an HCFC refrigerant?

20-30%

When evacuating a system, the use of a severely oversized vacuum pump could

Cause trapped water to freeze

Why should the oil be removed from a low-pressure system at 130F?

Less refrigerant will be contained in the oil at the higher temperature

A rupture disc on a recovery vessel for low-pressure refrigerants relievesa

15 psig

What should be on during vapor removal from a low-pressurerefrigeration system?

The system water pumps, recovery compressor, and recovery condenserwater should all be on

What is the result of raising the temperature of the room in which a low-pressure chiller is located?

Faster refrigerant recovery

To prevent freezing, when recharging an evacuated water-cooled chiller system with R-123, at what pressure or vacuum can liquid charging first begin

20 in Hg vacuum

Which of the following actions would always be considered "major" under EPA's regulations?

Replacement of an evaporator coil

When should an appliance NOT be evacuated all the way to theprescribed level?

When leaks in the appliance make evacuation to the prescribed level unattainable

Which of the following statements is true of recycling and recovery equipment?

It must be labeled as certified to meet EPA's requirements

Which of the following methods can be used to pressurize an R-1233zd system for the purpose of opening the system for a non-major repair?

Warming the liquid refrigerant in the system

How long must a technician evacuating refrigerant from appliances with a full charge ofmore than 5 pounds and less than 50 pounds that are being disposed of keep records of theevent?

3 years

Which of the following always falls under the EPA definition for "major maintenance,service, or repair?"

Replacing a compresso

R-123 at a pressure of 18.1 inches Hg vacuum has a saturation temperature of

40 F

Identify the pressure corresponding to 32 F for R-123

20 inches of Hg vacuum

Where is the rupture disc located on a centrifugal chiller?

Evaporator

Which of the following is a reason to take an oil sample?

The unit has had a compressor burnout

What is the typical design burst pressure for a rupture disk on a low-pressure centrifugal air-conditioning system?

15 psig

Which of the following statements about R-1233zd is FALSE?

A. It is a SNAP approved replacement for low-pressure centrifugal compressor systems.

B. It is being considered for applications where R-123 might have been used.

C. It is suitable for air conditioning applications where cooling wateris used (large chiller applications).

D. It is mildly flammable

D. It is mildly flammable

If EPA regulations change after a technician has been certified

it is the technician's responsibility to comply with future changes

Why is it easier to have air enter gaskets and fittings on a low-pressure system than a high-pressure system?

because a low-pressure system operates in a vacuum

At what pressure does a rupture disc open on a low-pressure system?

at 15 psig

What is the easiest way to leak test a low-pressure system?

add warm water over the coil to raise the pressure to 10 psig

Why is it important not to exceed 10 psig when leak testing a low-pressure system?

because the rupture disc, located on the evaporator, may fail

When using an electronic leak detector, where is a water box leak tested after the water has beenremoved?

at the drain valve

What is used when leak testing a water tube on a low-pressure chiller?

a hydrostatic tube kit