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Free Practice Quiz Question List

4 Type III: Low-Pressure Appliances Online Quiz Questions

Use this free practice quiz with 20 questions to review 4 Type III: Low-Pressure Appliances, test your knowledge, and prepare for your next test or exam.

20 questions
01
True or false
1 point

True or false: For a low-pressure appliance, the required evacuation level is 25 mm Hg absolute regardless of whether the recovery equipment was manufactured before or after November 15, 1993.

  1. A

    True

  2. B

    False

02
Fill in the blank
1 point

When recharging a chiller, introduce refrigerant before to reduce the risk of freezing water in the tubes.

03
Choose one
1 point

A low-pressure chiller’s purge unit begins operating much more frequently than usual. What is the most useful interpretation of this clue?

  1. A

    The appliance is necessarily overcharged with refrigerant.

  2. B

    Air may be entering the system, possibly because of a leak.

  3. C

    The chiller has completed recovery.

  4. D

    The refrigerant is being intentionally vented.

04
Written response
1 point

In a refrigeration pressure reading labeled psia, what kind of pressure is being measured?

05
Written response
1 point

To approximately what temperature in °F should oil be heated before removal to reduce refrigerant remaining in solution?

06
Choose one
1 point

Through which valve should refrigerant be charged into a centrifugal chiller?

  1. A

    The condenser drain

  2. B

    The purge-unit exhaust

  3. C

    The evaporator charging valve

  4. D

    The oil receiver

07
Fill in the blank
1 point

After reaching the required evacuation level, wait several minutes and check whether the pressure .

08
True or false
1 point

True or false: Recovered refrigerant can generally be transferred to a new owner for reuse without reclamation, provided it came from a properly serviced appliance.

  1. A

    True

  2. B

    False

09
Choose one
1 point

For certification review, what is the maximum leak-test pressure for a low-pressure centrifugal chiller?

  1. A

    5 psig

  2. B

    10 psig

  3. C

    25 psig

  4. D

    50 psig

10
Choose one
1 point

Which service action is classified as a major repair of a refrigeration appliance?

  1. A

    Replacing an external temperature display

  2. B

    Cleaning the exterior of the appliance

  3. C

    Removing the evaporator for service

  4. D

    Adjusting a room thermostat

11
Choose all
1 point

Select all appropriate practices when recovering refrigerant from a low-pressure chiller.

  1. A

    Recover liquid early when possible.

  2. B

    Recover liquid only and leave vapor in the appliance.

  3. C

    Recover vapor as well as liquid.

  4. D

    After reaching the required level, wait and check whether pressure rebounds.

  5. E

    Treat the first reading at the required level as proof that recovery is complete.

  6. F

    Circulate or remove water from the chiller tubes during evacuation.

12
Choose all
1 point

For covered appliances containing at least 50 pounds of ozone-depleting refrigerant, select all correct EPA leak-repair trigger-rate matches.

  1. A

    Industrial process refrigeration: 30%

  2. B

    Industrial process refrigeration: 20%

  3. C

    Commercial refrigeration: 20%

  4. D

    Commercial refrigeration: 10%

  5. E

    Comfort cooling and other appliances: 10%

  6. F

    Comfort cooling and other appliances: 30%

13
Open ended
1 point

A technician is planning work in a low-pressure equipment room where a refrigerant leak may have occurred. Explain the oxygen-displacement hazard and describe the precautions needed before anyone enters.

14
True or false
1 point

A low-pressure chiller operating below atmospheric pressure can draw air and moisture inward through a leak even when refrigerant is not leaking outward at that moment. True or false?

  1. A

    True

  2. B

    False

15
Choose one
1 point

A chiller’s purge unit is operating frequently. Which interpretation is most appropriate?

  1. A

    The system is removing excess refrigerant after charging.

  2. B

    Air or other noncondensables may be entering the system through a leak.

  3. C

    The refrigerant charge is necessarily too high.

  4. D

    The appliance has completed recovery.

16
Choose one
1 point

A technician is recharging a chiller and wants to reduce the risk of freezing water in its tubes. Which charging sequence should the technician use?

  1. A

    Introduce liquid before vapor to cool the tubes rapidly.

  2. B

    Introduce liquid only, because vapor cannot be recovered.

  3. C

    Introduce vapor before liquid to reduce the risk of freezing water in the tubes.

  4. D

    Introduce air before refrigerant to equalize pressure.

17
Choose one
1 point

A technician is leak-testing a low-pressure centrifugal chiller. What is the maximum leak-test pressure for certification review?

  1. A

    5 psig

  2. B

    10 psig

  3. C

    25 psig

  4. D

    50 psig

18
Written response
1 point

You are identifying a refrigerant used in low-pressure equipment. Enter one common low-pressure refrigerant designation from the material.

19
Written response
1 point

Before removing oil from a low-pressure appliance, a technician heats it to reduce refrigerant remaining in solution. What approximate temperature should the technician use?

20
Choose one
1 point

After a chiller reaches its required evacuation level, its pressure rises during a wait of several minutes. What should the technician infer and do?

  1. A

    The appliance is definitely free of refrigerant and ready to open.

  2. B

    The purge unit has permanently removed all noncondensables.

  3. C

    Refrigerant may still be boiling from liquid or escaping from oil, so recovery may need to continue.

  4. D

    The recovery equipment has necessarily exceeded its high-pressure cut-out.