Midea MFA-12HRN1 General Information Manual page 45

MCAC-UTSM-2009-03
4.2 MFA-12HRN1and MFA-18HRN1
Check whether the height drop between the indoor unit and outdoor unit, the length of refrigerant pipe, and
the number of the bends meet the following requirements:
Capacity(Btu/h)
The max. height drop
The length of refrigerant pipe
The number of bends
4.2.1 The Procedure of Connecting Pipes
Caution:
All field piping must be provided by a licensed refrigeration technician and must comply with the
relevant local and national codes.
Do not let air, dust, or other impurities fall in the pipe system during the time of installation.
The connecting pipe should not be installed until the indoor and outdoor units have been fixed already.
Keep the connecting pipe dry, and do not let moisture in during installation.
Execute heat insulation work completely on both sides of the gas piping and the liquid piping. Otherwise,
this can sometimes result in water leakage.
1. Drill a hole in the wall (suitable just for the size of the wall conduit), then set on the fittings such as
the wall conduit and its cover.
2. Bind the connecting pipe and the cables together tightly with binding tapes.
3. Pass the bound connecting pipe through the wall conduct from outside. Be careful of the pipe
allocation to do on damage to the tubing.
4. Connect the pipes.
5. Expel the air with a vacuum pump. Refer to "How to expel the air with a vacuum pump" for details.
6. Open the stop valves of the outdoor unit to make the refrigerant pipe connecting the indoor unit with
the outdoor unit in fluent flow.
7. Check the leakage. Check all the joints with the leak detector or soap water.
8. Cover the joints of the connecting pipe with the soundproof / insulating sheath (fittings), and bind it
well with the tapes to prevent leakage.
Caution:
Be sure to with insulating materials cover all the exposed parts of the flare pipe joints and refrigerant
pipe on the liquid-side and the gas-side. Ensure that there is no gap between them.
Incomplete insulation may cause water condensation.
Installation
12000
5m
Less than 15m
Less than 5
Installation of the Connecting Pipe
18000
10m
Less than 20m
Less than 8
43