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1 Low-Pressure Appliances and Chiller Fundamentals Online Quiz Questions

Use this free practice quiz with 20 questions to review 1 Low-Pressure Appliances and Chiller Fundamentals, test your knowledge, and prepare for your next test or exam.

20 questions
01
Choose one
1 point

A technician suspects a refrigerant leak while servicing a low-pressure chiller. Which response best protects people?

  1. A

    Continue working without ventilation if the leak is small.

  2. B

    Use suitable PPE and ventilation, and follow site-required detection and emergency procedures.

  3. C

    Energize the equipment to circulate refrigerant away from the work area.

  4. D

    Use compressed air to clear refrigerant from the appliance.

02
True or false
1 point

True or false: Recovery means bringing a system to a specified low-pressure endpoint, while evacuation means transferring refrigerant into a recovery cylinder.

  1. A

    True

  2. B

    False

03
Written response
1 point

What component separates and removes accumulated non-condensables from many low-pressure centrifugal chillers?

04
Choose one
1 point

Before deciding whether a low-pressure chiller’s operating pressure is normal, what should a technician consult?

  1. A

    Use 25 mm Hg absolute as the normal operating pressure for every low-pressure chiller.

  2. B

    Use atmospheric pressure as the normal operating pressure for every chiller.

  3. C

    Consult the equipment’s pressure–temperature data for the refrigerant and temperature.

  4. D

    Assume the operating pressure is the same whenever the chiller is centrifugal.

05
Written response
1 point

For standard Section 608 evacuation of a low-pressure appliance before opening it, what is the endpoint? Enter the value in mm Hg absolute.

06
Fill in the blank
1 point

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

07
True or false
1 point

True or false: Heating compressor oil to 130°F allows a technician to remove it without first reducing pressure to no greater than 5 psig.

  1. A

    True

  2. B

    False

08
Choose all
1 point

Select all appropriate practices when planning refrigerant recovery and evacuation for a chiller repair.

  1. A

    Recover vapor as well as liquid refrigerant.

  2. B

    During evacuation, circulate water through the chiller or remove it as appropriate for the equipment and repair.

  3. C

    Stop recovery once liquid refrigerant has been removed.

  4. D

    Leave water stationary in the chiller throughout evacuation, regardless of conditions.

09
Choose one
1 point

After a low-pressure appliance reaches its required recovery vacuum, its pressure rises during the wait period. What should the technician conclude and do?

  1. A

    Open the appliance immediately because the endpoint was reached once.

  2. B

    Add nitrogen until the pressure stabilizes.

  3. C

    Assume the pressure rise proves the gauge is defective.

  4. D

    Continue recovery as needed because refrigerant may remain in liquid or oil.

10
Choose all
1 point

Select all appropriate practices for leak-testing a low-pressure chiller.

  1. A

    Prioritize controlled hot water or the chiller’s built-in heating/pressurization device where appropriate.

  2. B

    If using nitrogen, use a regulator and suitable pressure-relief protection, and stay within the manufacturer’s pressure limit.

  3. C

    Use oxygen or compressed air if they are more readily available than nitrogen.

  4. D

    Exceed the manufacturer’s pressure limit briefly to make a leak easier to locate.

11
Choose one
1 point

A technician is handling a qualifying non-major repair to a low-pressure appliance that will not be followed by evacuation to the environment. What does the limited alternative require before opening the appliance?

  1. A

    Bring it to 25 inches of mercury vacuum using any available method.

  2. B

    Bring it to 5 psig by adding oxygen.

  3. C

    Bring it to 0 psig using an allowable method before opening it.

  4. D

    Bring it to 0 psig using nitrogen even if that requires subsequent purging.

12
Open ended
1 point

Describe how refrigerant moves through the four major components of a typical vapor-compression chiller, including what happens to it at each stage.

13
Choose one
1 point

A low-pressure appliance has both leaking and non-leaking sections that can be isolated. Which approach matches the specified service guidance?

  1. A

    Evacuate non-leaking sections to the specified level and take leaking sections to the lowest attainable level, not above 0 psig.

  2. B

    Take every section to 25 inches of mercury vacuum, regardless of leakage.

  3. C

    Pressurize leaking sections above 0 psig so that the leak can be found.

  4. D

    Leave non-leaking sections untreated and vent the leaking sections.

14
Written response
1 point

In a centrifugal chiller, which component uses a motor-driven impeller to raise refrigerant vapor's pressure and temperature?

15
Choose one
1 point

A chiller cools building return water by transferring its heat to refrigerant. In which component does the refrigerant absorb that heat and boil?

  1. A

    The evaporator

  2. B

    The compressor

  3. C

    The condenser

  4. D

    The expansion device

16
True or false
1 point

True or false: During normal operation, some sections of a low-pressure chiller can be below atmospheric pressure, allowing air to enter through leaks.

  1. A

    True

  2. B

    False

17
Choose one
1 point

A technician removes refrigerant from an appliance and collects it in a recovery cylinder. What is this process called?

  1. A

    Evacuation

  2. B

    Recovery

  3. C

    Condensation

  4. D

    Purge operation

18
Written response
1 point

Before opening a low-pressure appliance under the standard Section 608 evacuation requirement, what is the endpoint in mm Hg absolute?

19
Choose one
1 point

When recharging a centrifugal chiller, which procedure helps reduce the risk of freezing water in its tubes?

  1. A

    Introduce liquid before vapor through any service connection

  2. B

    Introduce liquid only, using the condenser charging connection

  3. C

    Introduce vapor before liquid through the designated evaporator charging valve

  4. D

    Introduce vapor and liquid simultaneously through the purge unit

20
Fill in the blank
1 point

A technician is investigating a problem specifically involving compressor lubrication. Which chiller subsystem should be examined? Complete the sentence: The technician should examine the chiller’s system.