Chapter 9

Question 1

Meeting that took place to set reduction rates of refrigerants that were destroying the ozone

Answer 1

Montreal protocol

Question 2

Used to prevent the loss of refrigerant

Answer 2

Low loss fitting

Question 3

To process refrigerant to like new specifications

Answer 3

Refrigerant Reclaim

Question 4

Use of a recovery machine to remove refrigerant from a system

Answer 4

Active Recovery

Question 5

Oil used with HFC refrigerant

Answer 5

Polyolester (POE) oil

Question 6

blend of two or more refrigerants that behave like a pure refrigerant

Answer 6

Azeotrope

Question 7

Consists of three oxygen molecules located in the stratosphere

Answer 7

Ozone

Question 8

When one or more refrigerants in a blend condense or evaporate at different rates than other refrigerants

Answer 8

fractionation

Question 9

Use of the system compressor or internal pressure to recover refrigerant

Answer 9

passive recovery

Question 10

non-ozone depleting refrigerant that does not contain chlorine or fluorine

Answer 10

Hydrocarbon (HC)

Question 11

valve that allows refrigerant to be charged or discharged from a system

Answer 11

Schrader valve

Question 12

Oil used mainly in automobile refrigeration systems

Answer 12

PAG oil

Question 13

warming process caused by the atmospheres absorption of heat energy radiated from the Earths surface

Answer 13

Greenhouse effect

Question 14

Index used to read chemicals that cause damage to the ozone layer in the stratosphere

Answer 14

Ozone Depletion Potential (ODP) index

Question 15

How do you check a recovery cylinder to see if there is oil in it without removing the valve assembly?

a. Attach a pressure gauge and check the vapor pressure.
b. Remove the refrigerant, weigh the cylinder and compare it to the TW.
c. Heat the cylinder and see if any oil vapor comes out of the vapor valve.
d. Pressurize the cylinder with nitrogen through the vapor valve to see if any oil comes out of the liquid valve.

Answer 15

b. Remove the refrigerant, weigh the cylinder and compare it to the TW.

Question 16

When using recovery equipment manufactured before November 15, 1993, what is the evacuation level for medium pressure appliances with the charge of less than 200 pounds?

a. O in Hg vacuum
b. 4 in Hg vacuum
c. 10 in Hg vacuum
d. 15 in Hg vacuum

Answer 16

b. 4 inches Hg vacuum

Question 17

The name/data plate on a hermetic compressor shows a lock rotor amp (LRA) rating of 30A. What is the rated load amp (RLA) rating of the compressor?

a. 25A
b. 10A
c. 6A
d. 5A

Answer 17

c. 6A

(divide LRA by 5; 30 Amps / 5 = 6 Amps)

Question 18

When naming refrigerants, what does the upper-case letter after the number signify/indicate for R-407A?

a. It is a blended refrigerant.
b. It is an Isomer of R-407
c. Same number of atoms but the molecular arrangement is different.
d. Same ingredients of R-407 but the proportions of the ingredients are different.

Answer 18

d. Same ingredients of R-407 but the proportions of the ingredients are different.

Question 19

T/F
When working on systems that use. flammable refrigerants, technicians should use non-sparking/spark-proof tools.

Answer 19

True

Question 20

T/F
Concentration of flammable refrigerant gas in the air above the upper exposure limit (UEL) will not ignite.

Answer 20

True

Question 21

T/F
Good ozone is in the troposphere.

Answer 21

False

Question 22

T/F
Ozone is produced through plant photosynthesis and the bonding of standard
oxygen molecules (Oz) with free oxygen (O) atoms.

Answer 22

True

Question 23

T/F
HC refrigerants are classified in the A3 group meaning they are non-toxic and non-flammable.

Answer 23

False

Question 24

ASHRAE Flammability and Toxicity Chart

Question 25

T/F When using propane as a refrigerant, ensure that it is refrigerant-grade and not fuel grade.

Answer 25

True

Question 26

T/F The lower case letter after the refrigerant number indicates that the refrigerant is an isomer of the numbered refrigerant, meaning it has the same molecular makeup but the atoms are arranged differently.

Answer 26

True

Question 27

T/F Three groups of mineral oil are naphthenic, aromatic and paraffinic.

Answer 27

True

Question 28

T/F HFC refrigerants work best with alkylbenzene oil.

Answer 28

False CFC and HCFC use Alkylbenzene Oil

Question 29

T/F POE oil stored in plastic containers can be contaminated by moisture that penetrates the plastic walls of the container.

Answer 29

True

Question 30

T/F If refrigerant is not going to be transported after recovery but reintroduced after a system repair, the liquid density of the refrigerant used to calculate recovery cylinder capacity can be replaced with 77°F instead of 130°F.

Answer 30

True

Question 31

A high pressure reading in a recovery tank is an indication of what?

Answer 31

Contaminants in the refrigerant

Question 32

Draw a picture of refrigerant being recovered from a system using the following components: 2-valve three hose manifold, recovery machine filter, dryer, refrigerant scale, and recovery cylinder.

Answer 32

Question 33

When using the Appion method of recovering refrigerant, at what pressure will you flip the recovery cylinder back to the upright position and open the blue valve on the manifold?

Answer 33

75-100 psig

Question 34

The fastest method of removing refrigerant from a system is to take it out in the ___________ state.

Answer 34

Liquid State

Question 35

List four ways to speed up recovering refrigerant from a system.

Answer 35

1. Liquid State 2. Shorter Hoses 3. Recovery Hose 4. 4-valve 4-hose manifold

Question 36

How are the internal components of an oil-less recovery unit lubricated?

Answer 36

By the refrigerant

Question 37

What is used to store refrigerant from a system when using the passive recovery method?

Answer 37

A recovery cylinder in vacuum

Question 38

Very high-pressure refrigerants have liquid saturation pressures above 340 pig at a liquid saturation temperature of 104°F. Which refrigerant is an example of a very high-pressure refrigerant? a. R-134a b. R744 c. R-12 d. R-410A

Answer 38

b. R744

Question 39

What is the minimum type of EPA certification required to service medium, high and very high-pressure appliances? a. Core and Type I b. Core and Type lI c. Core and Type Ill d. Core and Types I, Il and III (Universal)

Answer 39

b. Core and Type lI

Question 40

How many chlorine atoms does it take to destroy 5,000,000 ozone molecules?

Answer 40

50 Chlorine Atoms (1 chlorine atom -> 100,000 ozone molecules)

Question 41

Data/Name plate on a condensing unit shows a factory charge of 149 oz of R-410A refrigerant. Only 3 lbs 14 oz was removed so the leak in the system could be sealed. How much refrigerant leaked out of the system. Give your answer in pounds and ounces. (oz -> lbs = divide by 16 | lbs -> oz = multiply by 16)

Answer 41

(oz -> lbs = divide by 16 | lbs -> oz = multiply by 16) Step 1: 149 oz = 9.3126 Step 2: 3lbs 14oz = 3.875 Step 3 9.3126 - 3.875 = 5.4375 Step 4 5.4375 = 5lbs and 7oz 5lbs and 7oz leaked out of the system

Question 42

When using a solder-on piercing valve, how do you leak check the fitting before piercing the tubing?

Answer 42

Dry Nitrogen

Question 43

What is the recovery percentage for a small appliance when using a recovery machine manufactured after November 15, 1993?

Answer 43

90%

Question 44

What device prevents a recovery cylinder from being overfilled with refrigerant and oil when a cylinder is filled only by weight?

Answer 44

Float Switch