What steps should be taken before using a recovery unit to remove a charge

This is the second of four in our series of free practice tests on handling refrigerants in high-pressure appliances and servicing high-pressure refrigeration equipment. Our practice tests are among the best mobile-friendly tests on the web and render great on phones and tablets for students and apprentices on the go. Please consider sharing them with others that may find them useful, individually or in forums. Thanks… NT.

* NOTE: Having a pressure-temperature reference for commonly used refrigerants is required to answer some of the questions on our practice tests unless you have an amazing memory.

• Take this free test as often as you like.
• Contains 25 questions.
• Pressing the submit button immediately returns your resulting score.
• Passing score is 70%. (18 out of 25)
• Correct answer information is provided for questions answered incorrectly.
• Good luck!

Results

#1. When a refrigerant trace gas becomes absolutely necessary to use, which of the available refrigerants should be used to identify a leak?

CFC-12

HCFC-22

HFC-407c

HFC-410a

Correct answer is B:   HCFC-22

When a refrigerant trace gas becomes absolutely necessary to use, which of the available refrigerants should be used to identify a leak?   HCFC-22

#2. After refrigerant liquid has been recovered from a system, any remaining vapor is

purged to the atmosphere.

isolated in the system.

pumped into the system receiver.

condensed by the recovery system.

Correct answer is:  condensed by the recovery system.

After refrigerant liquid has been recovered from a system, any remaining vapor is condensed by the recovery system.

#3. An oil sample should be taken when

a new filter dryer has been installed.

the compressor has burned out.

the unit is not cooling properly.

recycled refrigerant has been added to the unit.

Correct answer is B:   the compressor has burned out.

An oil sample should be taken when the compressor has burned out.

#4. In a refrigeration system with a TXV or other type of throttling device, the component directly following the condenser would be the

receiver.

metering device.

accumulator.

evaporator.

Correct answer is A:   receiver.

In a refrigeration system with a TXV or other type of throttling device, the component directly following the condenser would be the receiver.

#5. Recovered refrigerant may contain which of the following?

Acids

Moisture

Oils

All of the above

Correct answer is D:  All of the above

Recovered refrigerant may contain acids, moisture, and oils among other noncendensibles.

#6. The backseating of a suction shut-off valve will close the

suction line and compressor port.

compressor and gauge port.

gauge port.

compressor port.

Correct answer is C:  gauge port.

The backseating of a suction shut-off valve will close the gauge port.

#7. Which repair would always be considered “major” under the EPA’s regulations?

Replacement of an evaporator coil.

Replacement of a filter dryer.

Replacement of a schrader valve core.

Replacement of a condenser fan motor.

Correct answer is A:  Replacement of an evaporator coil.

Which repair would always be considered “major” under the EPA’s regulations?  Replacement of an evaporator coil.

#8. R-410a requires certified recovery and recycling equipment rated for at least

240 psig

300 psig

400 psig

500 psig

Correct answer is C:  400 psig

R-410a requires certified recovery and recycling equipment rated for at least 400 psig.

#9. A compressor heater is used to

prevent refrigerant vaporization.

remove entrained water.

prevent acid pitting.

reduce the amount of refrigerant in the lubricating oil.

Correct answer is D:  reduce the amount of refrigerant in the lubricating oil.

A compressor heater is used to reduce the amount of refrigerant in the lubricating oil.

#10. Your recovery/recycling machine has R-502 refrigerant in it. You now have to recover refrigerant from a unit with R-22. What must be done before the R-22 refrigerant can be recovered/recycled?

Nothing as long as the recovery machine is not full.

Change the expansion valve on the recovery machine.

Change the filter and expansion valve on the recovery machine.

Recover as much of the R-502 as possible from the recovery machine, change the filter, and evacuate.

Correct answer is D:  Recover as much of the R-502 as possible from the recovery machine, change the filter, and evacuate.

Your recovery/recycling machine has R-502 refrigerant in it. You now have to recover refrigerant from a unit with R-22. What must be done before the R-22 refrigerant can be recovered/recycled?  Recover as much of the R-502 as possible from the recovery machine, change the filter, and evacuate.

#11. The fastest way to recover refrigerant from a system is to remove it in the _______ phase.

final

initial

liquid

vapor

Correct answer is C:  liquid

The fastest way to recover refrigerant from a system is to remove it in the liquid phase.

#12. Before using a recovery unit to remove a charge, what steps should be taken?

Check service valve positions.

Check the oil level in the recovery unit.

Evacuate recovery unit and recovery tank.

All of the above.

Correct answer is D:  All of the above. 

Before using a recovery unit to remove a charge, the following steps should be taken:

• Check service valve positions.
• Check the oil level in the recovery unit: 
• Evacuate recovery unit and recovery tank.

#13. A deep vacuum is usually measured in

psig

psia

inches of Hg

microns

Correct answer is D:  microns

A deep vacuum is usually measured in microns.

#14. Before transferring refrigerant to an empty cylinder

the refrigerant should be chilled.

the refrigerant should be mixed.

the cylinder should be heated.

the cylinder should be evacuated to avoid mixing air with the recovered refrigerant.

Correct answer is D:  the cylinder should be evacuated to avoid mixing air with the recovered refrigerant.

Before transferring refrigerant to an empty cylinder the cylinder should be evacuated to avoid mixing air with the recovered refrigerant.

#15. To recover liquid refrigerant, you must connect one hose to the

compressor suction valve.

compressor discharge valve.

liquid line.

top of the condenser.

Correct answer is C:  liquid line.

To recover liquid refrigerant, you must connect one hose to the liquid line.

#16. A system can be evacuated to only atmospheric pressure when

the repair is major.

the repair is followed by an evacuation of the appliance to the environment.

leaks in the appliance make evacuation to the prescribed level unattainable.

the appliance is being disposed.

Correct answer is C:  leaks in the appliance make evacuation to the prescribed level unattainable.

A system can be evacuated to only atmospheric pressure when leaks in the appliance make evacuation to the prescribed level unattainable.

#17. The vacuum pump used to evacuate a system should be capable of pulling a vacuum of

10mm Hg

20mm Hg

500 microns

1000 microns

Correct answer is C:  500 microns.

The vacuum pump used to evacuate a system should be capable of pulling a vacuum of 500 microns.

#18. While R-410a is a high-pressure refrigerant, it can be stored in the back of your service van as long as

the temperature inside the vehicle does not exceed 125F. This is the same guidance given for R-22 and other common refrigerants.

the temperature inside the vehicle does not exceed 125F. But R-22 can be stored in vehicles with temperatures exceeding 125F.

the temperature inside the vehicle does not exceed 155F. This is the same guidance given for R-22 and other common refrigerants.

the temperature inside the vehicle does not exceed 155F. But R-22 can be stored in vehicles with temperatures exceeding 155F.

Correct answer is A:   the temperature inside the vehicle does not exceed 125F. This is the same guidance given for R-22 and other common refrigerants.

While R-410a is a high-pressure refrigerant, it can be stored in the back of your service van as long as the temperature inside the vehicle does not exceed 125F. This is the same guidance given for R-22 and other common refrigerants.

#19. When under a deep vacuum, the motor winding of a hermetic refrigeration compressor

will be damaged if energized.

must be kept warm to operate properly.

will be protected by its insulation.

will overheat only if the crankcase heater is energized.

Correct answer is A:  will be damaged if energized.

When under a deep vacuum, the motor winding of a hermetic refrigeration compressor will be damaged if energized.

#20. Which statement is NOT true regarding recycling and recovery equipment manufactured after November 15 1993?

It must be tested by an EPA approved third party.

It must meet vacuum standards more stringent than those met by equipment manufactured before 15 November 1993.

It must be equipped with low-loss fittings.

It must have an oil separator.

Correct answer is D:  It must have an oil separator.

#21. When a unit is opened for servicing, the ________ should always be replaced.

thermostat

metering device

crankcase heater

filter-drier

Correct answer is D:  filter-drier

When a unit is opened for servicing, the filter-drier should always be replaced.

#22. When servicing an operating unit that has a receiver/storage tank, the

compressor should be isolated off.

liquid should be recovered last.

refrigerant should be recovered into the receiver.

gauge pressure should be achieved by venting.

Correct answer is C:   refrigerant should be recovered into the receiver.

When servicing an operating unit that has a receiver/storage tank, the refrigerant should be recovered into the receiver.

#23. Use ________ to remove ice from a sight glass.

an alcohol spray

water

R-11 refrigerant

a screw driver or flat file

Correct answer is A:  an alcohol spray

Use an alcohol spray to remove ice from a sight glass.

#24. The refrigerant pressure inside an R-12 unit which is at room temperature (72F) and not operating is

approximately 74 psig

approximately 154 psig

approximately 214 psig

approximately 304 psig

Correct answer is A:  approximately 74 psig.

The refrigerant pressure inside an R-12 unit which is at room temperature (72F) and not operating is approximately 74 psig.

#25. You are going to service a newer residential split-system air-conditioner. You would expect to find the system charged with which refrigerant?  R-410a What steps should be taken before using a recovery unit to remove a charge quizlet?

What steps are taken before using recovery equipment?

What is the first thing you do before you recover refrigerant from a system?

How do you recover refrigerant step by step?