AC

Question 1

The pressure at which the refrigerant changes state from a vapor to liquid

Answer 1

Condensing pressure

Question 2

The pressure at which the refrigerant changes state from a liquid to vapor

Answer 2

Evaporating pressure

Question 3

T/F Superheat always refers to a vapor.

Answer 3

T

Question 4

T/F All liquid must be vaporized for superheating to occur

Answer 4

T

Question 5

Subcooling always refers to a liquid at a temperature _____ its saturation temperature for a given pressure.

Answer 5

Below

Question 6

One main function of a compressor

Answer 6

Circulate refrigerant

Question 7

One function of discharge line

Answer 7

Carry high pressure superheated vapor from compressor discharge valve to condenser

Question 8

Receiver acts as a ____.

Answer 8

Surge tank

Question 9

T/F Liquid line transfers low pressure subcooled liquid to metering device.

Answer 9

F high pressure

Question 10

Meters liquid refrigerant from liquid line to evaporator

Answer 10

Metering device

Question 11

The metering device is a restriction that separates high pressure side from _____ _____ _____ in refrigerant system.

Answer 11

Low pressure side

Question 12

The evaporator, like the condenser, acts as a _____ _____.

Answer 12

Heat exchanger

Question 13

_____ transports low pressure superheated vapor from evaporator to compressor.

Answer 13

Suction line

Question 14

4 stages of refrigeration cycle

Answer 14

Expansion
Evaporation
Compression
Condensation

Question 15

Superheat on the systems low side can be divided into 2 types:

Answer 15

Evaporator superheat

Total (compressor) superheat

Question 16

What controls evaporator superheat?

Answer 16

TXV

Question 17

Low evaporator loads can be caused by 4 things:

Answer 17

Iced up or dirty coil

Defrost circuit malfunction causing coil icing

End of refrigeration cycle

Low refrigerant charge

Question 18

When liquid refrigerant enters the compressor crankcase while compressor is running is called _____.

Answer 18

Flooding

Question 19

Name 2 things could cause slugging to occur?

Answer 19

Bad TXV

Low load

Question 20

3 metering devices

Answer 20

Thermostatic expansion valve (TXV)
Automatic expansion valve (AXV)
Capillary tube

Question 21

If the diameter is too small _____,

Answer 21

the evaporator will be starved.

Question 22

If a capillary tube is over/under charged, it will backup the excess liquid in the condenser causing high/low head pressure.

Answer 22

Over

High

Question 23

It is extremely important to install a filter drier before the capillary tube to catch any _____ _____.

Answer 23

Foreign objects

Question 24

3 main functions of TXV

Answer 24

Provide constant amount of evaporator superheat

Keep evaporator full of refrigerant

Prevents flood back of refrigerant to compressor

Question 25

Color codes R11 R12 R134A

Answer 25

Blue Yellow Blue

Question 26

Air may enter refrigeration system because of what 3 things?

Answer 26

Tube, gasket or flange leaks Poor charging procedures Poor recovery or recycling procedures

Question 27

2 types of leak detection

Answer 27

Electronic | Ultraviolet (UV) Fluorescent

Question 28

What 2 things are detrimental to a refrigeration system?

Answer 28

Air | Moisture

Question 29

New and replacement compressors come shipped with dry nitrogen that needs to be removed and _____ prior to use.

Answer 29

Evacuated

Question 30

If the contamination from a burned out and or sludged compressor reaches a replacement compressor, the new compressor will probably _____.

Answer 30

Burn out

Question 31

The oil from a burn out can cause serious skin irritation and possible _____.

Answer 31

Burns

Question 32

When do you evacuate a compressor?

Answer 32

When it has been isolated from the rest of the system

Question 33

TEWI

Answer 33

Total Equivalent Warming Impact

Question 34

CAA

Answer 34

Clean Air Act

Question 35

The substances affected by the CAA were divided into __ main classes.

Answer 35

2

Question 36

Section 608 of the CAA prohibited individuals from knowingly _____.

Answer 36

Venting off refrigerant

Question 37

Recovery and recycling equipment manufactured after November 15, 1993 must be equipped with _____ fittings.

Answer 37

Low-loss

Question 38

Owners with charges greater than _____ are required to repair substantial leaks.

Answer 38

50 lbs

Question 39

How many types of EPA technician certifications are there?

Answer 39

4

Question 40

Why is it necessary to have superheat in a refrigeration system?

Answer 40

To ensure refrigerant is in a vaporized state.