Type 3

Question 1

What should be done to reduce refrigerant loss from a purge unit on a R-123 chiller?
A. Leak test and repair the chiller.
B. Seal the purge unit discharge line.
C. Pipe purge unit back into the low side.
D. Pipe purge unit back into recovery unit.

Answer 1

A. Leak test and repair the chiller.

Question 2

Leak testing a low pressure refrigeration system with nitrogen in excess of 10 psig could cause which of the following to fail?
A: CONDENSER TUBES. 
B: PURGE UNIT SHELLS. 
C: EVAPORATOR
D: Rupture Disc

Answer 2

D: Rupture Disc

Question 3

What precaution should be taken prior to recovering refrigerant from a chiller suspected of having tube leaks

Answer 3

A. Drain the water sides of the evaporator and condenser

Question 4

Industrial process refrigeration when the leak rate exceeds

Answer 4

D: 30%

Question 5

What must a system owner do once the threshold leak rate has been exceeded on any low pressure system using an ozone depleting refrigerant?

Answer 5

D: Repair the applicance enough to bring the leak rate below the threshold, retrofit, or retire the applican

Question 6

passed the initial verification leak test, when must a follow-up verification test be conducted

Answer 6

C: within 10 days

Question 7

A typical setting for the high pressure cut-out control on a recovery unit used for evacuating the refrigerant from a low pressure chiller is

Answer 7

C: 10 psig

Question 8

Refrigenant removal from a low-pressure system starts with

Answer 8

B: Liquid removal

Question 9

Why should the oil be removed from a low-pressure system at 103’F

Answer 9

B: Less refrigenant will be contained in the oil at the higher temperature

Question 10

A rupture disc on a recovery vessel for low-pressure refrigeants relieves at

Answer 10

C: 15psig

Question 11

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

Answer 11

B: Faster refrigerant recovery

Question 12

What is a typical advantage of a water cooled recovery unit?

Answer 12

Faster recovery of large quantities of refrigerant

Question 13

Charging liquid R-245fa into a low-pressure refrigeration system under a vacuum greater than 18 inches. Hg vacuum can cause the

Answer 13

C: System water to freeze

Question 14

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

Answer 14

It must be equiped with low-loss ball valves and flare fittings

Question 15

to pressurized an R-1233zd system for the purpose of opening the system for a non-major repair?

Answer 15

Warming the liquid refrigerant in the system

Question 16

What evacuation level must technicians recover refrigerant to before disposing a low-pressure applicane?

Answer 16

25mm of Hg absolute

Question 17

require purge unit

Answer 17

These system operate below atmospheric pressure

Question 18

reason to take oil sample

Answer 18

the unit has had a compressor burnout

Question 19

prevent freezing by increasing pressure using a gas such as

Answer 19

Nitrogen

Question 20

Pressure relief valves must NOT be installed

Answer 20

In series

Question 21

which of the following statements about R-1233zd is FALSE

Answer 21

It is SNAP approved replacement for low-pressure centrifugal systems

Question 22

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

Answer 22

The condenser or the chiller barrel tubes are leaking

Question 23

ASHRAE Guideline 3, check for leak

Answer 23

1 mm Hg to 2.5mm Hg

Question 24

Chillers belong to which EPA leak repair category

Answer 24

Comfort colling

Question 25

After recovering liquid refrigerant

Answer 25

Recover the vapor refrigerant

Question 26

What should be on/off during vapor removal from a chiller?

Answer 26

Water pumps, recovery compressor, recovery condenser warer should all be on

Question 27

How do you determine when enough vapor has entered the refrigeration system before you charge refrigerant liqid

Answer 27

Refrigerant saturation temperature increases above 32’F

Question 28

major

Answer 28

Replacement of Evaporator coil / Compressor /

Question 29

R-123 at 14.7 PSIA will boil at

Answer 29

82’F

Question 30

safety precautions should be adhered to for low-pressure systems

Answer 30

Use glove and safety goggles when working with liquid refrigerant

Question 31

where should the discharge from a rupture disc be piped for venting

Answer 31

Outdoors

Question 32

burst pressure for a rupture disc

Answer 32

15 psig

Question 33

Place a leak detector probe to check gas leaks into the water box with water removed

Answer 33

In the drain valve opening

Question 34

Which of the following CANNOT be used as a reason to extend the applicance leak repair deadline

Answer 34

Necessary repair parts are unavailable

Question 35

The use of severly oversized vacuum pump could

Answer 35

Cause trapped water to freeze

Question 36

lowest access point on a low-pressure centrifugal air-conditioning appliance

Answer 36

Evaporator charging valve

Question 37

indicates air in a low-pressure system

Answer 37

High head pressure

Question 38

refrigerant go after it leave the purse unit of a low-pressure centrifugal system

Answer 38

The evaporator

Question 39

AHREA Standard 15-2013 requires the use of sensors and alarms to detect

Answer 39

All refrigerant safety groups

Question 40

Excessive running of a purse unit

Answer 40

Leaking sysstem

Question 41

replacement appliance used a refrigerant exempt from the venting prohibition

Answer 41

18 months

Question 42

where is refrigerant added to a centrifugal machine

Answer 42

Evaporator charging valve

Question 43

activate an alarm and mechanical ventilation

Answer 43

when the TLV-TWA Threshold Limit Value - Time Weighted Average is exceeded