Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 Manual page 272

chain reaction proceeds continually, the water in the system will be more and more. It will cause
the capillary ice blocking; at the same time, acidity of working substance circulated in the
system will be higher and higher (the value of PH is lower and lower), and it may corrode the
components and parts in the system. The phenomenon of copperizing would happen. When
installing A/C, the action should be prompt, and after opening the plug of connecting pipe we
must tighten the nut in 5 minutes. The time of discharging air should be enough. When
installing A/C, the sweat drops into the connecting pipe is forbidden; the infusible impurity
mixed in the system is forbidden. It is better to install the A/C of refrigerant R410A split type in
fine weather, do not do it in rainy day, nor humid weather.
2.2.4 The chlorine ion could react with POE oil to form acid, and the acid corrodes the components
and parts of refrigerant system. So pollute the system with chlorine ion in installation is
forbidden, such as sweat beads and other impurities that contain chlorine ion.
2.2.5 Whatever the reason we must change the drier, if the refrigerant system is exscinded in service,
after we exscind the refrigerant system, we must use something to wrap the fracture lest the
moisture in air enters into the system. The time that refrigerant system expose to air should be
less than 5 minutes.
2.2.6 Must weld the drier into system in 5 minutes in order to isolate the air when changing it.
Otherwise it will influence the performance of the drier.
2.2.7 Must use special pump after service. The lubricant should be the grease. The pump couldn't be
used to vacuum the A/C of refrigerant R22, otherwise it would cause the contamination of
refrigerant, and influence the performance of A/C. The time of vacuuming must be over 25
minutes, Otherwise the moisture in system will be too high, and affect the stability of A/C.
2.2.8 If need to change the components and parts, must use the special one of R410A in service.
Using the components and parts of R22 is forbidden; otherwise it would affect the stability of
A/C.
The refrigerant R410A should be placed in environment under 30 . If the refrigerant has been
placed in environment above 30 , it is necessary to store the refrigerant in the environment below
30 for more than 24 hours. Otherwise the component of refrigerant would be changed and it
affects the performance of A/C.
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