Mitsubishi Electric MXZ-2A52VA, Installation Manual

Page: 5 / 10

5
5. INDOOR/OUTDOOR UNITS CONNECTION FINISHING AND TEST RUN
5-1 FLARED CONNECTIONS
PIPE LENGTH AND HEIGHT DIFFERENCE
Limits 2A52VA
Pipe length per indoor unit 20 m max.
Total pipe length for multi-system 30 m max.
Height difference* 15 m max.
No. of bends per indoor unit 20 max.
Total No. of bends for multi-system 30 max.
* If the outdoor unit is installed higher than the indoor unit, max. height difference is reduced to 10 m.
Refrigerant adjustment ....... If pipe length exceeds 20 m, additional refrigerant (R410A) charge is required.
(The outdoor unit is charged with refrigerant for total pipe length up to 20 m.)
Pipe length
Up to 20 m No additional charge is required.
Exceeding 20 m
Additional charge is required.
(Refer to the table below.)
Refrigerant to be added 20 g/m × (refrigerant piping length(m)-20)
●
For pipe size, see the table below.
SELECTING PIPE SIZE
The diameter of connection pipes differs according to the type and capacity of indoor units. Match the diam-
eters of connection pipes for indoor and outdoor units according to the following table.
Model
name
Pipe size for indoor unit
Allowable
connection
pipe size
22
25
35
Liquid pipe ø6.35 mm ø6.35 mm
Gas pipe ø9.52 mm ø9.52 mm
Valve size for outdoor unit
A
UNIT
Liquid pipe ø6.35 mm
Gas pipe ø9.52 mm
B
UNIT
Liquid pipe ø6.35 mm
Gas pipe ø9.52 mm
MXZ-2A52VA
Outdoor
unit
Indoor unit UNIT
Indoor unit UNIT
PIPING PREPARATION
1
If you use commercially available copper pipes, use the following table for pipe speci fi cations.
Outside diameter Wall thickness
Liquid pipe ø6.35 mm 0.8 mm
Gas pipe ø9.52 mm 0.8 mm
2
For insulation material, use 8 mm-thick heat-insulating expended polyethylene with a speci fi c gravity of
0.045.
3
Ensure that the 2 refrigerant pipes are insulated to prevent condensation.
4
Refrigerant pipe bending radius must be 100 mm or more.
CAUTION:
Be sure to use the insulation of speci fi ed thickness. Excessive thickness may cause incorrect installa-
tion of the indoor unit and lack of thickness may cause dew drippage.
5-2 FLARING WORK
●
Main cause of gas leakage is defect in fl aring work.
Perform fl aring work correctly in the following proce-
dure.
1. Pipe cutting
●
Cut the copper pipe correctly with pipe cutter.
2. Burrs removal
●
Completely remove all burrs from the cut cross
section of the pipe.
●
Put the end of the copper pipe downward to pre-
vent burrs from dropping in the pipe.
3. Putting nut on
●
Remove fl are nuts attached to indoor and outdoor
units, then put them on pipe having completed
burr removal. (not possible to put them on after
fl aring work)
●
Flare nut for R410A pipe may differ from R22 pipe
depending on the diameter of pipe.
Copper
pipe
Good
No good
Tilted Uneven Burred
Burr
Copper pipe
Spare
reamer
Pipe cutter
Flare nut
Copper pipe
90
A
B
SG79Y644H01.indd 5 SG79Y644H01.indd 5 29.11.2005 17:04:14 Uhr 29.11.2005 17:04:14 Uhr