MACS 609 CERTIFICATION
QUESTIONS AND ANSWERS
CORRECT 100%
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf system is: -
ANSWERApproved by some vehicle manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that they: -
ANSWERContribute to trapping heat
Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? -
ANSWERSludge
How much time do manufacturers suggest for proper system evacuation? -
ANSWER30 to 45 minutes
Why are shut-off valves located within 12 inches from the "vehicle end" of A/C
service equipment hoses? - ANSWERTo minimize venting of refrigerant
The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: - ANSWERThe refrigerant may only be used in newly manufactured
vehicles with components specifically designed for it
Select the statement that best describes the chemical and operating characteristics
of HFO-1234yf. - ANSWERHFO-1234yf is similar to, but not the same as, HFC-134a
If an HFC-134a A/C system still has pressure after the first refrigerant recovery
process is complete (including the five-minute pause), additional recovery is
necessary until the system vacuum level remains stable for: - ANSWER2 minutes
Paid technicians who service or repair buses using HCFC-22 as refrigerant, and/or
service or repair aircraft or ship/boat cargo refrigeration equipment: - ANSWERMust
be Section 608 Type II Certified
Specific safety information for managing incidents involving refrigerants and other
chemicals (inhalation, spills, fires, etc.) is found in the: - ANSWERMaterial safety
data sheet (MSDS) for the chemical
To what does Global Warming Potential (GWP) refer? - ANSWERRelative ability to
produce global warming effect
When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: - ANSWERMake sure the compressor is operating
, PAG lubricant: - ANSWERIs hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: - ANSWER0.15 ounce (4 grams) per year
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, which would indicate that the system still contains
some refrigerant? - ANSWER5 minutes
A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. - ANSWER12 inches
To what does Ozone Depletion Potential (ODP) refer? - ANSWERRelative ability to
destroy ozone
Which type of tank must be used during the transfer of refrigerant? - ANSWERTanks
marked DOT 4BA
When can HFC-134a become combustible in a mobile air conditioning system? -
ANSWERIf shop air is used in the system in an attempt to check for leaks and HFC-
134a is present
Mineral-based lubricants are used in which type of mobile A/C system? -
ANSWERCFC-12
How much moisture is removed from a mobile A/C system during a typical
evacuation? - ANSWERPossibly none
When recovery/recycling equipment is used to remove refrigerant from a mobile A/C
system, how much lubricant will be removed during the operation? -
ANSWERGenerally, very little, if any
Mobile A/C system design changes, new service procedures and equipment have
been developed for what reason? - ANSWERTo reduce lifetime refrigerant
emissions
Why is it necessary to ensure that service port caps containing good seals are
installed? - ANSWERTo minimize refrigerant loss
Which of the following is NOT a factor in how much refrigerant can be recovered
from an A/C system? - ANSWERThe age of the vehicle
The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: - ANSWERThe refrigerant may only be used in newly manufactured
vehicles with components specifically designed for it
HFO-1234yf has been tested and found compatible with: - ANSWERPAG oil
QUESTIONS AND ANSWERS
CORRECT 100%
The use of ultraviolet (UV) or fluorescent dyes in an HFO-1234yf system is: -
ANSWERApproved by some vehicle manufactures but not by others
One effect of some refrigerant gases in the atmosphere is that they: -
ANSWERContribute to trapping heat
Which item is not mentioned in the SAE J2099 Standard of refrigerant purity? -
ANSWERSludge
How much time do manufacturers suggest for proper system evacuation? -
ANSWER30 to 45 minutes
Why are shut-off valves located within 12 inches from the "vehicle end" of A/C
service equipment hoses? - ANSWERTo minimize venting of refrigerant
The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: - ANSWERThe refrigerant may only be used in newly manufactured
vehicles with components specifically designed for it
Select the statement that best describes the chemical and operating characteristics
of HFO-1234yf. - ANSWERHFO-1234yf is similar to, but not the same as, HFC-134a
If an HFC-134a A/C system still has pressure after the first refrigerant recovery
process is complete (including the five-minute pause), additional recovery is
necessary until the system vacuum level remains stable for: - ANSWER2 minutes
Paid technicians who service or repair buses using HCFC-22 as refrigerant, and/or
service or repair aircraft or ship/boat cargo refrigeration equipment: - ANSWERMust
be Section 608 Type II Certified
Specific safety information for managing incidents involving refrigerants and other
chemicals (inhalation, spills, fires, etc.) is found in the: - ANSWERMaterial safety
data sheet (MSDS) for the chemical
To what does Global Warming Potential (GWP) refer? - ANSWERRelative ability to
produce global warming effect
When performing engine pre-heat for refrigerant removal, the technician should do
ALL of the following EXCEPT: - ANSWERMake sure the compressor is operating
, PAG lubricant: - ANSWERIs hygroscopic (absorbs moisture)
Electronic leak detectors certified to SAE J2791 have the capability of identifying
leakage rates as low as: - ANSWER0.15 ounce (4 grams) per year
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, which would indicate that the system still contains
some refrigerant? - ANSWER5 minutes
A/C system service equipment hoses must be equipped with shutoff valves located
within _______ from the "vehicle end" of the hoses. - ANSWER12 inches
To what does Ozone Depletion Potential (ODP) refer? - ANSWERRelative ability to
destroy ozone
Which type of tank must be used during the transfer of refrigerant? - ANSWERTanks
marked DOT 4BA
When can HFC-134a become combustible in a mobile air conditioning system? -
ANSWERIf shop air is used in the system in an attempt to check for leaks and HFC-
134a is present
Mineral-based lubricants are used in which type of mobile A/C system? -
ANSWERCFC-12
How much moisture is removed from a mobile A/C system during a typical
evacuation? - ANSWERPossibly none
When recovery/recycling equipment is used to remove refrigerant from a mobile A/C
system, how much lubricant will be removed during the operation? -
ANSWERGenerally, very little, if any
Mobile A/C system design changes, new service procedures and equipment have
been developed for what reason? - ANSWERTo reduce lifetime refrigerant
emissions
Why is it necessary to ensure that service port caps containing good seals are
installed? - ANSWERTo minimize refrigerant loss
Which of the following is NOT a factor in how much refrigerant can be recovered
from an A/C system? - ANSWERThe age of the vehicle
The U.S. EPA has classified HFO-1234yf as "Acceptable, subject to use conditions."
That means: - ANSWERThe refrigerant may only be used in newly manufactured
vehicles with components specifically designed for it
HFO-1234yf has been tested and found compatible with: - ANSWERPAG oil
