Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 Manual page 271

about 30 minutes, and vacuity is less than 133Pa.
1.3 Precautions:
1.3.1 Regulations
Being liquefied vapor, R-407C and R-410A are high-pressure vapor, the high-pressure gas regulation is
applicable. Before use it, please refer to high-pressure gas regulation. To prevent the high-pressure
vapor from causing damage, the regulation should be followed.
1.3.2 Usage of vessel
Being high-pressure vapor, R-407C and R-410A are contained in high-pressure vessel. The
safety condition of vessel is good, but if you don't use it carefully, you may damage the vessel
and cause accident.
1.3.3 Storage
Although R-407C and R-410A are nonflammable, when they are stored with the normal
high-pressure gas, we should place them in the good ventilation area.
In addition, there are safe devices in the high-pressure vessel. Please note that when the
temperature (fusible valve) or pressure (spring safe valve) is up to a certain value, it will eject
vapor.
1.3.4 Ventilation
Because R-407C and R-410A are heavier then air, they will go down. If room is full of the
leakage vapor, the density of oxygen will decrease, and cause people suffocated.
In addition, if you light the fire when there is R-407C in the air, it will produce the toxic gas with
pungent odor and corrosiveness.
1.3.5 Precautions about health
For R-407C, R-410A and normal liquefied high-pressure vapor, please don't contact with skin
directly, and prevent being splashed into eyes and avoid drinking.
1.3.6 The following are the urgent disposal methods:
Splash into eyes:
Wash eyes with pure water for more than 15 minutes, and don't knead the eyes or blink.
Please wash eyes with watery boric acid water if the ache gets heavy.
To avoid the accident, please ensure that you wear the protection glasses.
Contact with skin directly
The temperature will decrease rapidly by evaporation if R-407C and R-410A expose to air in
liquid phase. So if the liquid contacts with skin directly, it may cause frostbite. If there are freeze
burns, please go to see the doctor immediately.
2. The service rules of the R410A product
2.1 There are some differences between air conditioner of R410A s and that of R22:
2.1.1 The compressor used is different, it is a new refrigerant compressor (special);
2.1.2 The air conditioner of new refrigerant R410A has a drier, while the A/C of R22 doesn't have.
2.1.3 There is no difference between the evaporator, condenser and system pipe of new refrigerant
R410A A/C and that of R22 A/C in appearance. The requirement of new refrigerant R410A A/C
for craft is higher, and the amount of moisture and impurity in the system is less than that of A/C
using R22. The resistance to pressure is higher.
2.1.4 The manufacture process is different, the requirement of air conditioner using R410A for craft is
high.
2.2 Refrigerant system:
2.2.1 The high pressure of refrigerant system is 3.0 Mpa, and the low pressure is 1.2 Mpa. (The
value is 1.5 times more than that of R22 under the same condition)
2.2.2 When installing the split type of new refrigerant R410A, all connecting pipes must be special
pipes of R410A. Discharging air must use refrigerant R410A, and couldn't misuse the
connecting pipe and refrigerant of A/C using R22. Otherwise, it will destroy the stability of A/C.
2.2.3 Because the compressor of refrigerant R410A split type uses POE oil, which can react with
moisture to form water and acid. The water produced by reaction could react further, and if the
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