Midea MCCU-03CN1A, Installation Manual

4

installation manual

NOTE

The service valves of the outdoor unit should be completely 

closed(as original status).Every time to connect,first to loosen 

nuts, then connect the flare pipes within 5 minutes. If  the nuts 

have been loosened for a long time, dusts and other impurities 

may enter the pipe system and may cause malfunction.So 

please expel the air out of the pipe with refrigerant before 

connection.

Expel the air after connecting the refrigerant pipe with the 

indoor unit and the outdoor unit.

Then fasten the nuts at the service valves.

Bend the connecting pipe of small wall thickness.

Cut out a proper concave at the bending part of the 

insulating pipe.

Then expose the pipe(cover it with tapes after bending).
To prevent twist of deforming, please bend the pipe at a 

proper radius.

Fig 3.3

Make the ends straight 

The bending angle should not exceed 90 .
Bending position is preferably in the middle of the bendable pipe. 
Do not bend the pipe more than three times.
Be sure to use the same insulating materials when you buy the 

brass pipe. (More than 9mm/0.35in thick) 

Be sure to use two wrenches simultaneously when you 

connect or disconnect the pipes.

2)    Place The Pipe

Drill a hole in the wall (suitable just for the size of the wall 

sleeve), then set on the fittings such as the wall sleeve and its 

cover.

Bind the connecting pipe and the cables together tightly with 

binding tapes.
Pass the bound connecting pipe through the wall sleeve from 

outside. Make sure of the pipe allocation not to damage the 

copper tubes.

3)

5)

6)

7)

4)

Connect the pipes. 

Expel the air with a vacuum pump or refrigerant.

Open the service valves of the outdoor unit .

Check the refrigerant leakage. Check all the joints 

with the leak detector or soap water.

Cover the joints of the connecting pipe with the 

insulation foam, and bind them well with the tapes to 

prevent potential leakage.

4    REFRIGERANT PIPE

4.1  Size of joint pipes for outdoor unit

Model

Gas side

Liquid side

Φ12.7/0.501in

Φ12.7/0.501in

Φ19/0.748in

Φ6.35/0.25in

Φ9.52/0.375in

Φ9.52/0.375in

the size of main pipe(mm)

03/05

07

10

Size of joint pipes for 410A outdoor unit

Table 4-1

Base on the following tables, select the diameters of 

the outdoor unit connective pipes. In case of the 

main accessory pipe large than the main pipe, take 

the large one for the selection.

Fig 4.1

Outdoor unit 

Max.pipe length L≤30m(10/14/16)

    Drop height between indoor

unit and outdoor unit 

H≤10m/32.9ft (03/05/07)

H≤20m/65.8ft(10/14/16)

Indoor unit

Flaring

1)

Cut a pipe with a pipe cutter. 

(Refer to Fig.5-1)

Insert a flare nut into a pipe and flare the pipe.

Fig 5.1

5.1   Expel The Air

Fasten the nut

2)

Put the connecting pipes at the proper position,

wrench  the  nuts  with  hands  then  fasten  it  with 

two wrenches simultaneously. 

(Refer to Fig 5.2)

Fig 5.2

5    REFRIGERANT PIPE CONNECTION

90

Lean     crude     burr

Φ19/0.748in

Φ9.52/0.375in

14/16

Max.pipe length L≤20m(03/05/07)