printable flash cards

7/22/13 Printable Flash Cards

www.flashcardmachine.com/print/?topic_id=1152012 1/99

Term 1

What are the typical uses of the center

port of gauge set?

Definition 1

Used during evacuation, charging and

recovery procedures.

Term 2

What color are the gauges on a

manifold gauge set?

Definition 2

Low pressure is blue, High pressure is

red.

Term 3

What are the typical ranges of

pressure measurements used on the

gauges of a manifold gauge set?

Definition 3

High side is 0 to 500 PSIG; Low side is

0 to 350 PSIG and 0 to 30 in. Hg below

atmospheric pressure.



Term 4

Is the refrigerant leaving a condenser

at a high or low pressure? Is it a liquid

or a gas?

Definition 4

High pressure, liquid.

Term 5

Is the refrigerant entering the

expansion valve (variable meteringdevice) a liquid or gas?

Definition 5

Liquid, high pressure.

Term 6

Is the pressure of the refrigerantentering the compressor high or low?

Definition 6

Low pressure vapor.



Term 7

Where in a refrigerant circuit does a

liquid boil to absorb heat?

Definition 7

In the evaporator.

Term 8

The refrigerant in the suction line is a

gas that has been heated above itssaturation. What is this condition

called?

Definition 8

Superheated vapor.

Term 9

What can cause liquid refrigerant tomigrate to a compressor crankcase?

Definition 9

If the compressor is located in thecoldest location in the circuit.



Term 10

List two conditions that can quicklydamage a compressor that is starting

to run?

Definition 10

Operating while in a deep vacuum orwhen the service valves are closed.

Term 11

What system failures require taking an

oil sample?

Definition 11

A compressor burnout or if the unit

has had a leak.

Term 12

Is flushing with refrigerant an

acceptable tube cleaning method?

Definition 12

No.



Term 13

In addition to preventing and repairingleaks, what else should a technician

do to conserve refrigerant?

Definition 13

Recover and recycle used refrigerants.

Term 14

What factors affect the speed of an

evacuation?

Definition 14

Pump size, hose length, hose

diameter, size of system to be

evacuated, ambient temperature,suction line size, and the amount of

moisture in the system.

Term 15

How should gauge set hoses be sized

for use in evacuating a system?

Definition 15

Use the shortest length and the largestdiameter possible for the quickest

evacuation. At least as large as the

vacuum pump inlet.



Term 16

When evacuating, what is the benefitof using short hoses with large

diameters?

Definition 16

Reduces emissions, pressure drop

and evacuation time.

Term 17

which connection determines the

preferred size of hoses used with avacuum pump?

Definition 17

The vacuum pump inlet.

Term 18

As the capacity and suction hose size

increase, what happens to the time

needed for an evacuation?

Definition 18

Time is reduced.



Term 19

What purpose is served by heating a

system during dehydration?

Definition 19

To speed up moisture removal.

Term 20

Does a thorough evacuation remove

moisture from a system?

Definition 20

Yes.

Term 21

What can happen to oil in the

compressor if the moisture is left in an

operating system?

Definition 21

The oil will form hydrofluoric and

hydrochloric acids which will corrode

the internal parts of the system.



Term 22

What is the result of over-evacuating a

system?

Definition 22

No damage will be done.

Term 23

How can a system be leak checked

using a low pressure gauge?

Definition 23

Vacuum reading will rise when

vacuum pump is turned off.

Term 24

How close should the vacuum gauge

be connected to the vacuum pump

during evacuation?

Definition 24

As far away as possible.



Term 25

When measuring the vacuum of a

system being evacuated, the system

must be isolated. What must be done

to the vacuum pump?

Definition 25

Turn it off and valve it off.

Term 26

What is ozone?

Definition 26

3 atoms of oxygen. It blocks much of

the harmful ultraviolet radiation (uv-b)

emitted from the sun and it keeps our

earth's temperature stable.

Term 27

How much ozone can a chlorine atomdestroy in the stratosphere?

Definition 27

One atom can destroy 100,000 ozonemolecules.



Term 28

What is Ozone Depletion Potential

(ODP)?

Definition 28

The ability of any chemical to deplete

the ozone layer.

Term 29

What is CFC?

Definition 29

Chlorofluorocarbon.

Term 30

Which refrigerants are CFC's?

Definition 30

R-11,12,113,114.



Term 31

Which chemical in the CFC refrigerants

does the most damage to the ozonelayer?

Definition 31

Chlorine.

Term 32

What is an HCFC?

Definition 32

Hydrochlorofluorocarbons.

Term 33

Which refrigerants are HCFC's?

Definition 33

R-22,123.



Term 34

Which is more harmful to the ozonelayer, a CFC or an HCFC?

Definition 34

CFC's.

Term 35

What is it about CFC's that make them

more harmful to the stratosphere?

Definition 35

Chemical strength, they will not

breakdown in the lower atmosphere.

Term 36

What is an HFC?

Definition 36

A fluorocarbon that contains no

chlorine.



Term 37

Which refrigerants are HFC's?

Definition 37

R-134a,404a,407c,410a.

Term 38

What is the ODP of the HFCrefrigerant?

Definition 38

Zero.

Term 39

Which refrigerants contain chlorine?

Definition 39

CFC's and HCFC's.



Term 40

Which refrigerants have high ODP?

Definition 40

CFC's.

Term 41

Which refrigerants have low ODP?

Definition 41

HCFC's, HFC's are zero.

Term 42

What is an azeotrope refrigerant?

Definition 42

A mixture of two or more compoundswhere the mixture behaves like a

single chemical.



Term 43

Is one of the components of R-500 aCFC?

Definition 43

Yes

Term 44

Does stratospheric ozone help or hurt

the work of the earth's protectiveshield?

Definition 44

It helps.

Term 45

What chemical in the stratosphere tellsus ozone depletion is occurring?

Definition 45

Chlorine-monoxide.



Term 46

How do we know the chlorine in thestratosphere is coming from CFC's?

Definition 46

The increase in chlorine and fluorinepresent in the stratosphere, matches

the increase in emissions of CFC's.

Term 47

How do we know CFC's get to the

stratosphere?

Definition 47

From high altitude air sampling

measurements.

Term 48

What role does the ozone layer play in

protecting the earth?

Definition 48

It blocks much of the harmful

ultraviolet radiation (uv-b).



Term 49

What are the effects on health fromincreased ultraviolet radiation?

Definition 49

Skin cancer, cataracts, humanimmunity is reduced.

Term 50

What are the effects on theenvironment?

Definition 50

Timber growth is reduced, crop yields

lowered, marine life and the food chainare impaired.

Term 51

Is ozone depletion a problem for the

United States only or a globalproblem?

Definition 51

A global problem.



Term 52

What is the Montreal Protocol?

Definition 52

A treaty that called for the reduction ofproduction of CFC's.

Term 53

The Montreal Protocol calls for the

regulation of what chemicals?

Definition 53

Ozone depleting compounds, CFC's,

HCFC's, and Halons.

Term 54

On what date was the production and

importation of all CFC's phased out?

Definition 54

In the U.S., after December 31, 1995.



Term 55

Where will we get replacements?

Definition 55

Through recovery of existing

refrigerants.

Term 56

What steps are called for by the CleanAir Act?

Definition 56

Taxes on production and use,

standards set for the recovery ofrefrigerants.

Term 57

What is prohibited by the Clean AirAct?

Definition 57

Venting.



Term 58

Do state and local laws have priorityover federal law? Can they be less

strict?

Definition 58

No. Cities or states can create theirown laws but they must be at least as

strict as federal laws.

Term 59

To prevent damage to the ozone layer,

the U.S. is making laws to capture theCFC's now in use. What else does the

new law do to restrict the release ofCFC's?

Definition 59

Allows states and municipalities tocreate their own laws to prevent and

monitor the release of CFC and HCFCmaterials into the atmosphere.

Term 60

By recovering refrigerants, we ensureadequate supplies and prevent

venting. What else does the recoveryof refrigerants accomplish?

Definition 60

Prevents stratospheric ozone

depletion.



Term 61

The Clean Air Act phases out

CFC/HCFC production and prohibitsventing. What else does it require?

Definition 61

Standards to be set for recovery of all

refrigerants prior to appliance serviceand disposal.

Term 62

Falsifying or failing to keep required

records, failing to reach requiredevacuation levels and knowingly

releasing CFC or HCFC refrigerants,are a violations of the Clean Air Act.

What activity with a substituterefrigerant is also a violation?

Definition 62

Knowingly venting CFC's, HCFC's andtheir substitutes.

Term 63

Which refrigerants must be recoveredprior to opening a system?

Definition 63

All refrigerants as of 11-15-1995.



Term 64

What releases of a CFC and HCFC areviolations of the Clean Air Act?

Definition 64

Any knowingly vented refrigerants.

Term 65

On what date did it become illegal tovent CFC and HCFC refrigerants?

Definition 65

July 1, 1992.

Term 66

Which appliances are covered by

Section 608?

Definition 66

Any device which contains and uses aclass 1 or class 2 substance as a

refrigerant and is used for householdor commercial purposes.



Term 67

What is the primary reason the EPA

requires a service aperture or processstub on all appliances?

Definition 67

For adding or removing refrigerant

from the appliance.

Term 68

Who sets the regulations for recoverymachines?

Definition 68

EPA.

Term 69

What is a "self-contained" recoverymachines?

Definition 69

A recovery machine that has its owncompressor to pump refrigerant out of

the system.



Term 70

Is HCFC-123 a "low or "high" pressure

refrigerant?

Definition 70

Low pressure.

Term 71

Is CFC-12 a "low" or "high" pressurerefrigerant?

Definition 71

High pressure.

Term 72

What is the smallest container in whichrefrigerants may be sold to a Section

608 certified technicians.

Definition 72

20 pounds.



Term 73

What must you do to the refrigerant inan appliance before disposing of the

appliance?

Definition 73

Recover refrigerant or verify that therefrigerant was previously recovered.

Term 74

Who is responsible for removing therefrigerant from household

refrigerators prior to disposal?

Definition 74

The final person in the disposal chain.(Scrap metal recyclers, landfill owner,

etc)

Term 75

What is the penalty for violation of the

Clean Air Act?

Definition 75

Fines up to $27,500 per violation perday and possible loss of technician

certification.



Term 76

How much is the bounty forinformation leading to a conviction?

Definition 76

Up to $10,000.

Term 77

What ca happen if a technician cannot

demonstrate an ability to use recoveryor recycling equipment?

Definition 77

May result in revocation of thetechnician's certification.

Term 78

What is the name of the process thatremoves refrigerant from a system and

stores it without testing orprocessing?

Definition 78

Recovery.



Term 79

What is the name for the process that

removes moisture and acids fromrefrigerant but does not test the

refrigerant?

Definition 79

Recycling.

Term 80

What is the name for the process thatremoves moisture and acids from

refrigerant and also chemically teststhe refrigerant?

Definition 80

Reclaim.

Term 81

What must be done with reclaimedrefrigerant before it can be legally

resold?

Definition 81

Chemically tested to ARI Standard 700,the purity level of factory new

refrigerant.



Term 82

What is the preferred instrument for

detecting small leaks?

Definition 82

Electronic leak detector and Ultrasonic

detector.

Term 83

What is an inert gas typically used inleak detection?

Definition 83

Dry nitrogen.

Term 84

What is typically indicated by adehydrated system failing to hold a

vacuum?

Definition 84

Leaks.



Term 85

What should be done when recoveringthe refrigerant form a system wherethe refrigerant has been improperly

mixed?

Definition 85

Recover into a separate container?

Term 86

Can mixed refrigerants be reclaimed?

Definition 86

No.

Term 87

What precautions should be takenwhen recovering refrigerant from

systems with multiple service valves?

Definition 87

Insure that liquid is not trapped

between service valves.



Term 88

What is the effect of low ambient

temperature on the time required tocomplete a recovery of refrigerant?

Definition 88

Increases recovery time.

Term 89

Technicians must explain tocustomers that recovery is necessary

and it is required by law. What elseshould the technician tell the

customer?

Definition 89

That all service personnel are duty

bound to follow the law and protect theenvironment.

Term 90

What is different about any leaks in

systems charged with a blendedrefrigerant?

Definition 90

Because they are blended, theingredients will leak at different rates.



Term 91

What is "temperature glide"?

Definition 91

A family of lines depicting pressureversus temperature curve.

Term 92

What is ternary blend?

Definition 92

A blend of three different refrigerants.

Term 93

How should systems using blendedrefrigerants be charged?

Definition 93

In liquid form into the high side of thesystem.



Term 94

Is there a "drop-in" refrigerant for CFC-

12?

Definition 94

No.

Term 95

How do you leak check an HFC-134asystem with a partial charge (no HFC-

134a detector available)?

Definition 95

Recover the remaining 134a and thenpressurize the system with nitrogen

and a trace charge of R-22 so you canuse an HCFC electronic leak detector.

Term 96

What is the preferred oil to be usedwith HFC-134a?

Definition 96

Ployolester.



Term 97

Can ester based oils be mixed withother oils?

Definition 97

No.

Term 98

What does "hygroscopic" mean?

Definition 98

Oil that absorbs moisture easily.

Term 99

What lubricant is recommended foruse with a ternary blend?

Definition 99

Depends on the blend: For HCFC's-Alkylbenze, For HFC's-Ployolester.



Term 100

Safety glasses and butyl-lined glovesshould be worn for what procedures?

Definition 100

When operating recovery or recycling

devices and when handling andrefilling refrigerant cylinders.

Term 101

What safety component must be used

whenever dry nitrogen is used topressurize a system?

Definition 101

Pressure regulator.

Term 102

Safety rules for technicians such as:no open flame or hot steam near a

refrigerant, never cutting or brazing a

charged refrigerant line, and neverusing oxygen to purge or pressurize

lines, are all important. Which oneshould a technician follow?

Definition 102

All of them.



Term 103

What is a Material Safety Data Sheet?

Definition 103

A sheet the states the safety ratingsand precautions to be taken for use

and handling of chemicals.

Term 104

What safety classification within theASHRAE standard is the most safe?

Definition 104

A1.

Term 105

What is caused by tie inhaling ofrefrigerant vapors?

Definition 105

Heart irregularities or Asphyxia.



Term 106

What is the major causes of death

involving refrigerants?

Definition 106

Oxygen deprivation.

Term 107

What breathing problem can be

caused by CFC-12?

Definition 107

Asphyxia.

Term 108

How can ice be removed from a sightglass?

Definition 108

With alcohol spray.



Term 109

What must be done with a badlycorroded relief valve?

Definition 109

It must be replaced.

Term 110

Where can you find the allowable testpressure on a system?

Definition 110

Unit data plate.

Term 111

Can oxygen be used to check forleaks? If not, why not?

Definition 111

No. Oxygen in the presence of oilunder high pressure can be explosive.



Term 112

What is the likely result of heating arecovery cylinder with an open flame?

Definition 112

Refrigerant will decompose into a toxic

material, venting of refrigerant int theatmosphere or the tank may explode.

Term 113

What is the primary purpose of adisposable cylinder?

Definition 113

For virgin refrigerant from themanufacturer.

Term 114

To what internal pressure should a

disposable cylinder be reduced to fordisposal?

Definition 114

Reduced to at least 0 PSIG.



Term 115

Should you ever use a disposablecylinder for refrigerant recovery?

Definition 115

No.

Term 116

To dispose of a cylinder you should be

sure all refrigerant is recovered andthe cylinder is no longer usable. What

else should you do?

Definition 116

Puncture the container beforedisposal.

Term 117

For safety, refrigerant chlinders shouldnot be rusted or damaged and alwaysproperly color coded. What additional

step should also be taken with thesecylinders?

Definition 117

Properly secured at all times.



Term 118

What is the proper color code for

recovery cylinders?

Definition 118

Gray with a yellow top.

Term 119

What is the maximum percent by

weight that a cylinder may be filled?

Definition 119

80%.

Term 120

What can happen if a cylinder is

overfilled?

Definition 120

Hydrostatic pressure could cause the

cylinder to explode.



Term 121

List three methods for measuring thefill level of a recovery cylinder.

Definition 121

Floats, thermistor type sensors, andweighing scales.

Term 122

Wow often must reusable cylinders behydrostatically tested?

Definition 122

Every five years.

Term 123

Why must only refillable cylinders beused for transport?

Definition 123

Federal code of regulations title 49(parts 100-177) states this.



Term 124

What must be affixed to a refrigerantcylinder prior to its shipment to a

reclaimer?

Definition 124

DOT classification tag.

Term 125

What is the purpose of a DOTclassification tag?

Definition 125

For transportation purposes.

Term 126

What is the correct shipping positionfor a refrigerant cylinder?

Definition 126

In a vertical or upright position withtheir valves at the top.



Term 127

What is the EPA definition of a smallappliance?

Definition 127

Appliances typically charged at the

factory with five pounds or less ofrefrigerant. Refrigerators and freezers

designed for home use, room airconditioners, including window andPTAC units, package heat pumps,

dehumidifiers, under the counter icemakers, vending machines and

drinking water coolers.

Term 128

Does the EPA require the repair ofleaks on small appliances?

Definition 128

Repair of leaks on small appliances isnot required, but leaks should be

repaired whenever possible.

Term 129

What EPA certification type musttechnicians have to service any

appliance that EPA calls a "smallappliance?"

Definition 129

Type 1 or Universal.



Term 130

What service aperture may be used on

small appliance?

Definition 130

Access tubes or process tubes.

Term 131

What is the name for a fitting, used toconnect a recovery device to an

appliance, which can close to preventloss of refrigerant form hoses?

Definition 131

Low-loss fitting. (shut-off valve)

Term 132

What is the primary purpose for usinghand valves or self-sealing hoses

when using a gauge set?

Definition 132

To prevent loss of refrigerant.



Term 133

Which refrigerants must be recoveredunder Section 608 of the EPA

regulations?

Definition 133

CFC, HCFC and HFC refrigerant.

Term 134

Is there a "drop-in" refrigerant for CFC-12?

Definition 134

No.

Term 135

What is the replacement refrigerant forCFC-12 in household refrigerators?

Definition 135

HFC-134a.



Term 136

What can be determined by taking anaccurate temperature and pressure

reading of a container holding a

recovered refrigerant?

Definition 136

Check for non-condensables and the

type of refrigerant.

Term 137

When doing a non-condensablescheck, a recovery cylinder should

stabilize in temperature before any

readings are taken. Why?

Definition 137

To find the correct pressure for that

temperature on a T/P chart.

Term 138

What is the internal pressure of CFC-

12 refrigerant stored at 75 deg. F?

Definition 138

77 PSIG.



Term 139

What is the exception to the rule that

says that someone servicing and

appliance must have at least one self-contained recovery machine available

at their place of business?

Definition 139

Only when the person is working on a

small appliance.

Term 140

Ammonia, hydrogen, and water can be

found in the refrigerators in somecampers and other recreational

vehicles. Should these compounds be

recovered with EPA approvedrecovery equipment?

Definition 140

No.

Term 141

May the nitrogen used for purging or

pressurizing a system be vented to theatmosphere?

Definition 141

Yes.



Term 142

When may a technician recover only80% of the refrigerant in a small

appliance?

Definition 142

In a system dependent recovery with a

non-operating compressor?

Term 143

May a technician use a passive

recovery machine for recovery from adomestic refrigerator?

Definition 143

Yes.

Term 144

What requirements are placed on

recovery machines built afterNovember 15, 1993?

Definition 144

Must be able to recover 80% of therefrigerant if the compressor is

inoperative or 90% if the compressoris operative. Must be EPA certified.



Term 145

When using a recovery machine

manufactured after November 15,1993, what percentage of the

refrigerant must be recovered in a

household refrigerator with anoperating compressor? What

percentage if the compressor is NOToperating?

Definition 145

80%, 90%.

Term 146

Is a certified technician responsible for

future changes in EPA regulations?

Definition 146

Yes.

Term 147

What type of certification is required to

purchase CFC and HCFC refrigerants?

Definition 147

Type 1.



Term 148

What must be done with any regulatedrefrigerant vented from a graduated

charging cylinder?

Definition 148

It must be recovered.

Term 149

What first step must you always takebefore starting a recovery of

refrigerant form any equipment?

Definition 149

Check which refrigerant is being used.

Term 150

What is a "system-dependent"

recovery machine?

Definition 150

System dependent recovery machines

rely on the compressor of the systembeing serviced, or the pressure of the

refrigerant to pump the refrigerant intoa recovery drum.



Term 151

Describe a system-dependent

(passive) recovery process for small

appliances.

Definition 151

Evacuate or cool a cylinder. Connect

the high and low hoses to the system.Pull refrigerant into the cylinder with

vacuum or the low tank pressure.

Term 152

What two conditions require that youaccess both the high and low side of

the system for refrigerant recovery?

Definition 152

When there is an inoperative

compressor on the system or whennecessary to reach required recovery

levels.

Term 153

What are the benefits of accessing the

low and high side access valves whenrecovering refrigerant from a system

with an inoperative compressor?

Definition 153

It speeds up recovery, improvesefficiency and may be necessary to

reach required recovery levels.



Term 154

How should you access the systemand should you run the compressor

when using a system-dependent

(passive) recovery on a refrigeratorwith an operable compressor?

Definition 154

Access the high side and run thecompressor.

Term 155

Which access valve (s) should youconnect to when recovering from a

system with an operating compressor

and a completely restricted capillarytube?

Definition 155

High side valve.

Term 156

When using a self-contained (active)

recovery device, what two conditionscan cause excessive pressure on the

recovery machine's high side?

Definition 156

A recovery container that is not

properly evacuated or one that has

unopened valve.



Term 157

Why should defrost heaters be turned

on during a recovery from a smallappliance?

Definition 157

To speed up refrigerant release fromthe oil.

Term 158

When should entrapped refrigerantfrom oil be recovered?

Definition 158

Any time oil is removed from a large

system and on small appliances whenusing system dependent recovery with

a non-operating compressor.

Term 159

What does striking the appliancecompressor do during a recovery?

Definition 159

Helps to free refrigerant that may betrapped in the oil.



Term 160

A recovery machine should be

checked daily for what?

Definition 160

Refrigerant leaks.

Term 161

Can a standard vacuum pump be used

as a recovery machine?

Definition 161

In theory yes, but unlikely. First itwould have to be certifiable, second it

would have to be connected to a non-

pressurized recovery container.

Term 162

Should technicians ever mix

refrigerants in the field?

Definition 162

No.



Term 163

How should you recover refrigerant

that is different from the refrigerant youusually recover?

Definition 163

Different refrigerants must be placed in

recovery vessels containing the sametype of refrigerant.

Term 164

What can a reclaimer do with any

mixed refrigerant you ship to them?

Definition 164

They may either refuse to process andreturn it at owner's expense or agree

to destroy the refrigerant for a

substantial fee.

Term 165

To ship recovered refrigerant you mustlabel the container and complete all

necessary paperwork. What else

should you do?

Definition 165

Use DOT approved cylinders.



Term 166

What federal agency sets thestandards for portable refillable tanks

or containers used to ship CFC orHCFC refrigerants?

Definition 166

Department of Transportation (DOT).

Term 167

Safety glasses and butyl-lined gloves

should be worn fro what procedures?

Definition 167

When you are connecting and

disconnecting hoses.

Term 168

Piercing valves are used for what

purpose?

Definition 168

To allow access to the sealed system

for recovery.



Term 169

On what materials are piercing valves

used?

Definition 169

Copper or aluminum refrigerant lines.

Term 170

What should be done to a piercingtype Schrader valve after it is installed

on a charged system?

Definition 170

It should be capped after any service

procedure.

Term 171

Why should solder-less type piercingvalves be removed after completion of

repairs?

Definition 171

To prevent leaks.



Term 172

What are the critical maintenance

checks done to a Schrader valve?

Definition 172

Periodically checked for leaks and

replaced if damaged.

Term 173

What does a pungent odor detected

after opening a system mean?

Definition 173

It might mean acids are present due to

a compressor burnout.

Term 174

What do you do if the oil is

contaminated?

Definition 174

Tubing flushing might be required.



Term 175

What system pressure would indicatea recovery should not be performed?

Definition 175

0 PSIG.

Term 176

What are the current methods used tomonitor the 80% fill level in a recovery

tank?

Definition 176

Floats, thermistor-type sensors andweighing scales.

Term 177

Why do large refrigerant leaks causesuffocation?

Definition 177

Refrigerants will replace air in aconfined space leading to possible

oxygen starvation.



Term 178

Before entering an area of a large leak

of refrigerant what apparatus must be

worn?

Definition 178

Self contained breathing apparatus.

Term 179

What should be done if a large leak

occurs and no breathing apparatus is

available?

Definition 179

Ventilate the space and leave the area.

Term 180

Which acids are formed when

refrigerant touches sources of high

heat?

Definition 180

Hydrochloric and hydrofluoric acidsand phosgene gas.



Term 181

What safety component must be used

whenever dry nitrogen is used topressurize a system?

Definition 181

Nitrogen tanks should be equippedwith a regulator.

Term 182

What information does DOT requirewhen shipping refrigerant cylinders?

Definition 182

Shipping papers must indicate the

refrigerant type and number ofcylinders.

Term 183

Which government agency sets the

standards for refillable refrigerantcylinders used to transport CFC and

HCFC refrigerants?

Definition 183

Department of Transportation (DOT).



Term 184

What component is always replaced

after a a system is opened for service?

Definition 184

Filter-driers.

Term 185

What is the purpose of the moisture

indicator in a sight glass?

Definition 185

To permit a check of moisture content

in the system.

Term 186

What does "back-seating" a suction

valve do?

Definition 186

Allows flow through the main line while

closing the access port.



Term 187

What will non-condensables do to the

pressures in a refrigerant circuit?

Definition 187

Increase discharge pressure.

Term 188

What causes oil foaming in a system

and where does it normally occur?

Definition 188

Oil that is mixed with refrigerant will

foam in the compressor crankcase.

Term 189

What system failures require taking an

oil sample?

Definition 189

Compressor burnout or if the unit has

had a leak.



Term 190

A vacuum pump that is too large can

cause what problem?

Definition 190

It can cause moisture to freeze in the

system?

Term 191

Where is a receiver typically installed

on a system?

Definition 191

At the outlet of the condenser.

Term 192

What will be the boiling temperature of

HFC-134a be at 0 PSIG?

Definition 192

-15 degrees F.



Term 193

Is it a requirement that recovery

machines contain an oil separator?

Definition 193

No.

Term 194

Which refrigerant is typically used on aresidential split system air

conditioner?

Definition 194

HCFC-22.

Term 195

Is the refrigerant leaving a receiver aliquid or a gas? Is it at a high or low

pressure?

Definition 195

Liquid, high pressure.



Term 196

What is the initial charging method of asystem when the charge is specified at

70 pounds?

Definition 196

Charged in liquid state.

Term 197

Is the receiver on the high or low side

of a system?

Definition 197

High side.

Term 198

What is the minimum recommendedcapability (measured in microns) of a

vacuum pump used for evacuations?

Definition 198

Should pull a vacuum of 500 microns.



Term 199

What is the pressure of a CFC-12

machine at 72 deg. F while the

machine is idle?

Definition 199

73 PSIG.

Term 200

What is the preferred unit of

measurement for checking a deep

vacuum?

Definition 200

Microns.

Term 201

Where is an accumulator located in arefrigeration system?

Definition 201

On the suction line before thecompressor.



Term 202

To prevent freezing of any moisture in

a CFC-12 system, vapor should first becharged until the pressure is at what

level?

Definition 202

33 PSIG

Term 203

What gas should be used during an

evacuation to increase pressure to

prevent freezing?

Definition 203

Dry nitrogen.

Term 204

What is the purpose of a compressorheater?

Definition 204

To reduce the amount of refrigerant inthe lubricating oil.



Term 205

How is moisture remaining from an

evacuation removed from therefrigerant in a system?

Definition 205

By the filter-drier.

Term 206

What is the preferred method of leak

checking a built-up system prior tocharging?

Definition 206

Bubble solution.

Term 207

What would a technician initially look

for during a visual inspection of aleaking hermetic system?

Definition 207

Stains around tubing and fittings.



Term 208

What is typically indicated by

excessive superheat on a high-pressure system?

Definition 208

Undercharged system, possibly the

result of a leaky system.

Term 209

Which refrigerant should be used for a

trace charge during leak detection?

Definition 209

R-22.

Term 210

How do you leak check an HFC-134a

system with a partial charge (no HFC-134a detector available)?

Definition 210

Recover remaining 134a, pressurizethe system with nitrogen and a trace

charge of R-22 so you can use an

HCFC electronic leak detector.



Term 211

For what purpose are soap bubbles

used in leak checking?

Definition 211

For a visual check for leaks.

Term 212

Shaft seals on an open type

compressor are susceptible to whatfailures?

Definition 212

Refrigerant leaks.

Term 213

What leak rate is permissible on

industrial and process refrigeration?

Definition 213

Effective 6/14/93, any leak rate of 35%or more on equipment with 50 lbs. of

charge or more must be repaired. Less

than 35% is permissible.



Term 214

What leak rate is permissible onequipment (other than industrial or

process equipment) that containsmore that 50 lbs. of refrigerant?

Definition 214

Less than 15% annually.

Term 215

What is the easiest way to check thetype of refrigerant used in a packaged

rooftop system?

Definition 215

By the equipment data plate.

Term 216

Refrigerant will recover fastest in

which phase, liquid or vapor?

Definition 216

Liquid.



Term 217

Which refrigerant line should a

recovery machine be attached to in

order to recover liquid refrigerant froma system?

Definition 217

To the liquid line.

Term 218

After a liquid recovery, what must be

done with the vapor still in the system?

Definition 218

Vapor recovery bust be performed.

Term 219

Recovering in a vapor phase reduces

unwanted loss of what?

Definition 219

Oil and unwanted contaminants fromthe system to the recovery machine

and recovery drum.



Term 220

On a high pressure system recovery,should the recovery cylinder be heated

or cooled?

Definition 220

Cooled.

Term 221

What must be done to a recoverymachine when changing to a different

refrigerant?

Definition 221

Clean out all residual refrigerant,

change oil, replace filters, evacuate

machine by pump-out or anothermachine.

Term 222

What besides filters must periodicallybe changed out on a recovery

machine?

Definition 222

Oil.



Term 223

Recovered refrigerant can contain oil

and acids. Name another compound

found in refrigerants?

Definition 223

Moisture.

Term 224

What is the water source for a

condensing coil on a water-cooled

recovery machine?

Definition 224

Municipal water tap.

Term 225

What access location should you use

when recovering from an air cooledsystem with its condenser several feet

above the evaporator?

Definition 225

Suction line.



Term 226

What access location should you use

when recovering from a system with

its condenser below the evaporator?

Definition 226

Liquid line.

Term 227

Before using a recovery unit, thetechnician should check service valve

positions and check the recovery unit

oil level. What additional step must betaken?

Definition 227

All solenoid valves should be open.

Term 228

What is the primary purpose for using

hand valves or self-sealing hoses

when using a gauge set?

Definition 228

To prevent loss of refrigerant whenconnecting and disconnecting hoses.



Term 229

What can cause recovery equipmentwith a hermetic compressor to

overheat when drawing a deep

vacuum?

Definition 229

No airflow over the compressor body

or no suction gas flow over the internalmotors, or a combination of the two.

Term 230

What is the reason for not operating a

hermetic refrigeration compressorwhile it is in a deep vacuum?

Definition 230

To prevent overheating thecompressor motor.

Term 231

What is the reason for not starting a

reciprocating compressor with itsdischarge service valve closed?

Definition 231

To prevent overheating thecompressor motor.



Term 232

When can a "system-dependent"

recovery device be used?

Definition 232

On small appliances as long as thedevice meets EPA standards and the

technician adheres to the servicing

procedures specified for the recoveryequipment. Cannot be used on

systems with more than 15 lbs. ofrefrigerant.

Term 233

What vacuum level must you reachwhen recovering from a system with

38 pounds of R-502 using a recovery

machine manufactured in 1995?

Definition 233

10 inches of Hg.

Term 234

What is EPA's definition of a "major

repair"?

Definition 234

Any repair that involves the removal ofthe compressor, evaporator,

condenser, or any auxiliary heat

exchanger coil.



Term 235

Prior to making a major repair, what

vacuum level must you pull when

using recovery equipmentmanufactured in 1996 on a unit with

215 lbs. of CFC-12?

Definition 235

15 inches of Hg.

Term 236

What vacuum level must you pull when

using recovery equipment

manufactured in 1992 when disposingof an appliance containing 12 lbs. of R-

500?

Definition 236

4 inches of Hg.

Term 237

Under what circumstances may atechnician recover the CFC refrigerant

in an appliance to atmosphericpressure only?

Definition 237

if leaks are in the system or if recovery

to target levels would contaminate therefrigerant.



Term 238

What procedure should be performed

on an empty recovery cylinder before it

is used for storing recoveredrefrigerant?

Definition 238

It must be evacuated of all non-

condensables.

Term 239

What may legally be done with therefrigerant recovered from a system in

order to replace a condenser coil?

Definition 239

Reused in the original system ortransferred to another system with the

same owner after it is checked so thatit is free of non-condensables.

Term 240

When servicing an operating unit witha receiver, where should the recovery

hoses be attached to the unit?

Definition 240

To the liquid line.



Term 241

In order to recover from a system withparallel compressors, the individual

compressors must be isolated. Why?

Definition 241

It isolates the refrigerant that must be

recovered from the rest of the system.

Term 242

Which refrigerant (s) require andequipment room monitor per ASHRAE

Standard 15?

Definition 242

All refrigerants.

Term 243

What protection is mandatory toprotect a system against damage from

excessive pressure?

Definition 243

A pressure relief device.



Term 244

Are multiple relief valves connected inseries or parallel?

Definition 244

Parrallel.

Term 245

Why is the use of a regulator requiredwhen using dry nitrogen?

Definition 245

To limit the outlet pressure of thenitrogen cylinder.

Term 246

How can ice be removed from a sight

glass?

Definition 246

Cleaned with an alcohol spray.



Term 247

How high should you pressurize an

idle low pressure chiller to prevent air

accumulation?

Definition 247

Slightly above atmospheric pressure.

Term 248

What effect does air in a chiller have onhead pressure?

Definition 248

Raises head pressure.

Term 249

What system failures require takingand oil sample?

Definition 249

A leak or major component failure(compressor burnout).



Term 250

Why must water be circulated througha chiller during refrigerant recovery?

Definition 250

To prevent freeze-up of the water aspressure is reduced on the refrigerant.

Term 251

What is the lowest access valve on alow pressure chiller?

Definition 251

The evaporator charging valve.

Term 252

Where is a centrifugal chiller's rupturedisk attached?

Definition 252

At the evaporator.



Term 253

What is the typical pressure setting for

a low pressure chiller's rupture disk?

Definition 253

15 PSIG.

Term 254

Where is the outlet of a rupture disk

discharged?

Definition 254

Outdoor for venting.

Term 255

How is a chiller typically charged?

Definition 255

Liquid through the evaporatorcharging valve.



Term 256

What minimum saturation temperature

needs to be achieved before liquid ischarged into a chiller?

Definition 256

Above freezing, typically 36 deg. F.

Term 257

To prevent freezing of water whencharging a chiller, what pressure

should be reached with vapor before

using liquid CFC-11?

Definition 257

16.9 inches of Hg.

Term 258

What could result from liquid

refrigerant being charged into a chillerthat is holding a 29 inch Hg. vacuum?

Definition 258

Can cause system water to freeze.



Term 259

What function is served by a purge

unit on a chiller?

Definition 259

Minimize the effects of contamination.

To remove non-condensables.

Term 260

What is the most likely cause of air

leaks into a chiller refrigerant circuit?

Definition 260

Gaskets and fittings.

Term 261

How is a purge unit connected on a

low pressure chiller?

Definition 261

The inlet of the purge unit is typically

connected to the top of the condenser.



Term 262

Where is the suction of a purge unit

connected?

Definition 262

The inlet of the purge unit is typically

connected to the top of the condenser.

Term 263

What is a high efficiency purge unit?

Definition 263

It removes non-condensables that

contain a low percentage ofrefrigerant. This adds to the value of

the purge drum in refrigerant

containment.

Term 264

Shaft seals on an open typecompressor are susceptible to what

failures?

Definition 264

Refrigerant leaks.



Term 265

Purge units work best when they arenot needed. How can purge unit

operating time be reduced?

Definition 265

By regular leak checking and repairing

any leaks on a regular schedule.

Term 266

What is the maximum pressure thatcan be used when leak checking a low

pressure chiller?

Definition 266

10 PSIG on low pressure equipment

that utilizes a rupture disk.

Term 267

What is the preferred method of leakchecking a charged low pressure

chiller?

Definition 267

By increasing the refrigerant pressure

using an external heat source or

running hot water through the chillertubes not to exceed 10 PSIG.



Term 268

Where should you check for leaksbetween a chiller refrigerant tube and

the water box?

Definition 268

The chiller barrel can be emptied of allwater and a leak check can be made at

the drain valve with the water off. If thetubes themselves require a leak check,

the check can be made with a

hydrostatic tube test kit.

Term 269

What is a hydrostatic tube test kit used

for?

Definition 269

To check for leaks in a chiller tubes.

Term 270

What leak rate is permissible on

industrial and process refrigeration?

Definition 270

Effective 6/14/93, any annualized leakrate of 35% or more on equipment with

50 lbs. of charge or more must berepaired. Less than 35% is

permissible.



Term 271

What leak rate is permissible onequipment other than industrial and

process equipment?

Definition 271

For appliances with 50 lbs. of chargeor more an annual leak rate of 15% or

more must be repaired. Less than 15%leak rate is permissible.

Term 272

According to ASHRAE 3-1990, whatrise is permitted in vacuum levelduring a standing vacuum test?

Definition 272

Starting at 1mm of Hg., after 12 hoursthe vacuum reading should not

increase to more than 2.5 mm of Hg.

Term 273

List two steps to reduce the run time ofa purge unit.

Definition 273

Regular leak checks and repair anyleaks.



Term 274

Why should the water side of theevaporator and condenser be drainedbefore recovering refrigerant from a

chiller suspected of having tubeleaks?

Definition 274

To prevent moisture form being drawn

into the refrigerant circuit.

Term 275

If a purge unit is operating excessively,

what problem can you expect to find?

Definition 275

Leaks.

Term 276

What condition would causecontinuous excessive moisture

collection in the purge unit of a lowpressure refrigeration system?

Definition 276

Leaks between the refrigerant circuit

and the water circuit.



Term 277

Why should oil be warmed prior toremoval from a low pressure chiller?

Definition 277

To vaporize any liquid refrigerant thatmight be trapped in the oil.

Term 278

After liquid recovery, what must bedone with the vapor still in the system?

Definition 278

Vapor recovery must be performed.

Term 279

Is recovery of refrigerant from a lowpressure appliance typically started

with liquid or vapor?

Definition 279

Start with liquid removal.



Term 280

Where is the connection made for thewater supply used on a water cooled

recovery unit?

Definition 280

Local water supply.

Term 281

What should be the maximumpressure on the discharge of a

recovery machine for low pressure

systems?

Definition 281

10 PSIG, because the rupture disk isset to open at 15 PSIG.

Term 282

What should be done with the waterpumps during a recovery form a low

pressure chiller?

Definition 282



Term 283

What is EPA's definition of a "majorrepair"?

Definition 283

Any repair that involves the removal of

the compressor, evaporator,condenser, or any auxiliary heat

exchange coil.

Term 284

What recovery vacuum must be met on

a low pressure appliance using amachine built in 1992?

Definition 284

25 inches of Hg.

Term 285

Why should you wait a few minutes

after reaching the required recoveryvacuum on an appliance to see if

pressure rises?

Definition 285

To see if refrigerant is still trapped inthe system.



Term 286

Under what circumstances may therecovery from an appliance bestopped without reaching the

prescribed level?

Definition 286

If the recovery would contaminate therefrigerant being recovered. (this level

cannot exceed 0 PSIG.)

Term 287

Is it a requirement that recycling andrecovery equipment be capable of

handling more than one refrigerant?

Definition 287

No.

Term 288

Is it permissible to warm the refrigerantunder EPA's regulations to pressurize

a low pressure system to do a non-

major repair?

Definition 288

Yes.



Term 289

What final vacuum level is required forrecovering refrigerant from a low

pressure system if the technician is

using recovery equipmentmanufactured BEFORE November 15,

1993? AFTER November 15, 1993?

Definition 289

25 inches of Hg, 25 mm of Hg.

Absolute (equal to about 29 inches ofHg.)

Term 290

A vacuum pump that is too large for a

particular system can cause whatproblem?

Definition 290

It can cause moisture to freeze in the

system.

Term 291

How can you prevent moisture from

freezing during dehydration?

Definition 291

You can raise the pressure with

nitrogen and allow the ice to melt, thencontinue with the evacuation.



Term 292

Are multiple relief valves connected inseries or parallel?

Definition 292

Parallel.

Term 293

ASHRAE Standard 15 coversrefrigerant level monitoring for what

refrigerants?

Definition 293

All refrigerants.

Term 294

According to ASHRAE Standard 15,

what is the standard for refrigerantconcentration for a machine room that

must not be exceeded without

activating an alarm and startingventilation in the machine room?

Definition 294

May not exceed the TLV-TWA.(Threshold limit value-Time weighted

average.)



Term 295

List four safety procedures that shouldbe followed when working with liquid

low pressure refrigerant.

Definition 295

1. Use refrigerant sensors inequipment room.

2. Avoid siphoning refrigerant by

mouth. 3. Wear butyl-lined gloves.

4. Wear safety glasses.

Term 296

What is the toxicity and flammability

rating of HCFC-123 per ASHRAEStandard 34?

Definition 296

B1.

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