MACS 609 Certification Flashcards

Questions and Answers

If lubricant is removed by recovery equipment during system refrigerant removal, what must be done with the lubricant?

Re-install lubricant removed by the recovery equipment

Before reuse, what must be done with HFC-134a that has been recovered from a mobile A/C system using recovery-only equipment?

Use it immediately without processing

Store it without any treatment

Recycle the HFC-134a before reuse using certified equipment (correct)

Dispose of it

When can HFC-134a become combustible in a mobile air conditioning system?

If shop air is used in the system in an attempt to check for leaks and HFC-134a is present

Which type of mobile A/C system will usually require additional time/precautions to extract all the refrigerant?

Accumulator type Signup and view all the answers

Electronic leak detectors certified to SAE J2791 have the capacity of identifying leakage rates as low as:

0.15 ounces per year Signup and view all the answers

When recovery/recycling equipment is used to remove refrigerant from a mobile A/C system, how much lubricant will be removed during the operation?

Generally, very little, if any Signup and view all the answers

Why is it necessary to ensure that service port caps containing good seals are installed?

To minimize refrigerant loss Signup and view all the answers

Which of the following statements is correct about flushing A/C systems?

Flushing solvents may remain in A/C systems, causing problems Signup and view all the answers

When using an HFC-134a refrigerant recovery machine, after completing the first recovery process, how long must you wait, then check the machine's gauges for a rise in pressure above vacuum?

5 minutes Signup and view all the answers

Which type of tank must be used during the transfer of refrigerant?

Tanks marked DOT 4BA Signup and view all the answers

When it has been determined that an A/C system has a low refrigerant charge, what should be done?

Perform a leak detection procedure Signup and view all the answers

One effect of some refrigerant gases in the atmosphere is that they:

Contribute to trapping heat Signup and view all the answers

Mixing CFC-12 and HFC-134a in the same system will:

Result in refrigerant cross contamination Signup and view all the answers

How much moisture is removed from a mobile A/C system during a typical evacuation?

Possibly none Signup and view all the answers

Paid technicians who service or repair mobile A/C systems using HFC-22 as refrigerant, or service cargo refrigeration equipment:

Must be Section 608 Type II certified Signup and view all the answers

HFO-1234yf is classified as 'A2L-mildly flammable.' This means:

It can ignite under certain circumstances Signup and view all the answers

Section 609 of the Clean Air Act requires that recovery/recycling equipment:

Must be registered with the EPA Signup and view all the answers

What is the advantage of using refrigerant identification equipment?

Allows the ability to determine what type of refrigerant is in system Signup and view all the answers

When performing engine pre-heat for refrigerant removal, the technician should do ALL of the following EXCEPT:

Make sure the compressor is operating Signup and view all the answers

If a large amount of lubricant is removed from a system during refrigerant recovery:

The system likely contained too much lubricant Signup and view all the answers

PAG lubricant:

Is hygroscopic (absorbs moisture) Signup and view all the answers

Specific safety information for managing incidents involving refrigerants and other chemicals (inhalation, spills, fires, etc) is found in the:

Material safety data sheet (MSDS) for the chemical Signup and view all the answers

What is not identified in the manual as a concern with field-coupled hoses?

Length of hose Signup and view all the answers

Which of the following is NOT a factor in how much refrigerant can be recovered from an A/C system?

The age of the vehicle Signup and view all the answers

HFO-1234yf can be used in:

Any light vehicle with an air conditioning system designed to use it Signup and view all the answers

Study Notes

Refrigerant Recovery and Management

Reinstall lubricant removed by recovery equipment during refrigerant removal.
HFC-134a must be recycled before reuse using certified equipment.
HFC-134a can become combustible if shop air is introduced while checking for leaks.
Accumulator type mobile A/C systems require more time and precautions to extract refrigerant.

Leak Detection and Equipment

Electronic leak detectors certified to SAE J2791 can identify leakage rates as low as 0.15 ounces per year.
Recovery/recycling equipment generally removes very little to no lubricant from A/C systems.
Service port caps with good seals are essential to minimize refrigerant loss.

A/C System Maintenance

Flushing A/C systems can leave solvents behind, potentially causing problems.
After the first recovery process with HFC-134a recovery machine, wait 5 minutes to check for pressure rise indicating remaining refrigerant.
Tanks marked DOT 4BA must be used for refrigerant transfer.

Refrigerant Charge and Environmental Impact

Perform leak detection if an A/C system has a low refrigerant charge.
Certain refrigerant gases in the atmosphere contribute to heat trapping.
Mixing CFC-12 and HFC-134a results in refrigerant cross contamination.

Moisture and Technician Certification

A typical evacuation of a mobile A/C system may remove no moisture.
Technicians servicing mobile A/C systems using HFC-22 must be Section 608 Type II certified.

Safety and Regulations

HFO-1234yf is mildly flammable (A2L) and can ignite under certain conditions.
Recovery/recycling equipment must be registered with the EPA under Section 609 of the Clean Air Act.
Refrigerant identification equipment helps determine the type of refrigerant in the system.

Best Practices in Refrigerant Handling

During engine pre-heat for refrigerant removal, do not ensure that the compressor is operating.
A large amount of lubricant removal indicates the system likely had excessive lubricant.
PAG lubricant is hygroscopic, meaning it absorbs moisture.

Chemical Safety and Equipment Concerns

Specific safety information for refrigerants and chemicals is found in the Material Safety Data Sheet (MSDS).
The length of field-coupled hoses is not identified as a concern in management manuals.
The age of the vehicle is not a factor in how much refrigerant can be recovered from an A/C system.

Applications of HFO-1234yf

HFO-1234yf can be used in any light vehicle with an A/C system specifically designed for it.

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Description

Test your knowledge on refrigerant recovery and lubricant management with these flashcards for MACS 609 certification. Each card covers essential practices for handling HFC-134a and lubricants in A/C systems. Perfect for those preparing for MACS certification exams.