Free Practice Quiz Question List

4 Evacuation and Dehydration Procedures Online Quiz Questions

Use this free practice quiz with 20 questions to review 4 Evacuation and Dehydration Procedures, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

True or false: A chiller’s compressor may be used to evacuate its refrigeration system.

A
True
B
False

Choose one

1 point

A chiller vessel contains standing water before evacuation. What should the technician do?

A
Continue evacuation until the vacuum pump removes all standing water.
B
Remove standing water using the manufacturer’s procedure before evacuation.
C
Use the compressor to move standing water out of the vessels.
D
Pressure-test the circuit with compressed air to clear the water.

Fill in the blank

1 point

To measure the chiller’s actual vacuum as accurately as practical, place the micron gauge .

Choose one

1 point

Which sequence follows the recommended order for leak checking and dehydration?

A
Evacuate first, then pressure-test only if the vacuum will not hold.
B
Begin deep dehydration before checking for leaks to save time.
C
Pressure-test for leaks, repair any leaks, and then begin evacuation.
D
Charge the system before pressure-testing it.

Written response

1 point

For a U.S. stationary appliance containing more than five pounds of refrigerant, what recovery evacuation level does EPA Section 608 list for a low-pressure appliance? Enter the numeric value; the answer will be displayed in mm Hg absolute.

Choose all

1 point

Which precautions apply when using nitrogen during service? Select all that apply.

A
Use dry nitrogen with a regulator.
B
Use oxygen if it is supplied at a low pressure.
C
Stay within the manufacturer’s pressure limits.
D
Ventilate the work area to prevent nitrogen from displacing breathable air.
E
Use compressed air instead of nitrogen when nitrogen is unavailable.

Choose one

1 point

A technician is preparing to set a chiller’s final vacuum target and standing-hold criteria. Which approach is appropriate?

A
Use the same final vacuum target and hold time for every chiller.
B
Follow the model-specific procedure rather than treating an example target as universal.
C
Use the recovery evacuation level as the deep-dehydration target.
D
Set the final target based on the pump-side gauge reading.

Fill in the blank

1 point

Before starting a vacuum-decay hold test, so the chiller is isolated from the pump.

Written response

1 point

What is the name of the test in which the system is isolated from the pump and its pressure rise is monitored during a hold period?

True or false

1 point

True or false: During a vacuum-decay test, a pressure rise that tends toward atmospheric pressure suggests a leak, but does not by itself prove the cause.

A
True
B
False

Choose all

1 point

Which checks support verifying both dryness and leak tightness before charging? Select all that apply.

A
Confirm that the system reaches and holds the manufacturer’s final vacuum target.
B
Treat a low micron reading at the pump while it is running as proof of dryness.
C
Confirm that the required pressure leak test is passed.
D
Use the recovery evacuation level as the only dryness criterion.
E
Check that the system meets the specified vacuum-hold criteria.

Open ended

1 point

Describe how a technician should proceed from leak checking through evacuation and vacuum-hold verification before charging a chiller. Explain why the recovery evacuation level is not the deep-dehydration target and why a pressure rise during an isolated hold test must be interpreted cautiously.

Choose one

1 point

During evacuation, moisture in a chiller cools enough to freeze. What effect can this have?

A
It eliminates the need to monitor absolute pressure.
B
It proves the system has a leak.
C
It can temporarily slow drying and make readings misleading.
D
It allows the compressor to complete evacuation.

True or false

1 point

True or false: If the system temperature changes between vacuum-decay readings, the technician can interpret the pressure trend without accounting for that temperature difference.

A
True
B
False

Choose one

1 point

Which statement correctly distinguishes evacuation from dehydration in a refrigeration circuit?

A
Evacuation removes moisture; dehydration removes refrigerant and air.
B
Evacuation removes refrigerant, air, and other gases; dehydration removes water vapor and moisture.
C
Evacuation tests for leaks; dehydration recovers refrigerant.
D
Evacuation and dehydration are two names for the same procedure.

Written response

1 point

In the YORK centrifugal chiller example (not a universal requirement), what is the initial evacuation hold-test value? Enter the value in microns.

Choose one

1 point

Which instrument and placement are suitable for monitoring deep vacuum in the chiller?

A
A conventional manifold gauge at the pump
B
A pressure gauge connected to the nitrogen regulator
C
A calibrated micron gauge at or near the chiller
D
A temperature probe at the pump inlet

Written response

1 point

Which type of gauge is not accurate enough to verify deep vacuum? Enter the gauge type.

Choose one

1 point

A chiller has a suspected leak before dehydration begins. What should the service team do first?

A
Repair leaks and complete the required pressure leak test before evacuation.
B
Begin evacuation and use the vacuum-decay test as the only leak check.
C
Evacuate first, then use the compressor to remove remaining air.
D
Skip leak testing if a micron gauge is installed at the pump.

Choose one

1 point

When beginning a vacuum-decay test, how should the chiller be configured so its pressure trend can be observed?

A
Leave the pump connected and running so it can hold the vacuum.
B
Open the circuit to atmosphere and monitor the pump.
C
Close all service ports before recording any starting reading.
D
Close the valve between the system and pump, then monitor the isolated system as directed.

4 Evacuation and Dehydration Procedures Online Quiz Questions

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