Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 173

Installation of indoor unit
4
Choose the floor bracket bolt location or the wall installation bolt location, and the location of the pipe
hole. Open the holes for the bolts and the pipe.
Choose the positions by the measured values.
Floor penetration
(Pipe hole)
Strictly adhere to the following measurements for the wall installation bolts.
Wall installation bolt
Here is the method to drill the holes on the wall.
Inside
-
Sealing plate
(1) Remove the front panel and the side panel.
(2) Eliminate looseness with a level adjusting screw.
(3) Firmly secure as instructed below.
The side panel and the front panel have been installed.
Case front panel
Top panel
Side
panel
Base
Wall installation
Wall installation 4 holes
Wall penetration (Pipe hole)
Floor installation 2 holes
Wall
Wall
Outside
Wall
Sleeve
Sleeve
Case side panel
Case front panel
Case front panel
Case side panel
Floor installation
Frame side
Use a washer
and a double
nut to secure
to the floor bolt
Floor bracket
(Accessory)
Use a washer
and a double
nut to secure
to the wall bolt
Refrigerant piping
5
Caution
l Use the new refrigerant pipe.
When re-using the existing pipe system for R22 or R407C, pay attention to the following items.
・Change the flare nuts with the attached ones (JIS category 2), and reprocess the flare parts.
・Do not use thin-walled pipes.
l Use phosphorus deoxidized copper alloy seamless pipe (C1220T specified in JIS H3300) for
refrigeration pipe installation.
In addition, make sure there is no damage both inside and outside of the pipe, and no harmful
substances such as sulfur, oxide, dust or a contaminant stuck on the pipes.
l Do not use any refrigerant other than R410A.
Using other refrigerant except R410A (R22 etc.) may degrade inside refrigeration oil. And air getting
into refrigeration circuit may cause over-pressure and resultant it may result in bursting, etc.
l Store the copper pipes indoors and seal the both end of them until they are brazed in order to avoid
any dust, dirt or water getting into pipe.
Otherwise it will cause degradation of refrigeration oil and compressor breakdown, etc.
l Use special tools for R410 refrigerant.
Work procedure
1. Remove the flare nut and blind flanges on the pipe of the indoor unit. (The connection of Liquid/Gas
side of heat exchange, Inlet/outlet of the expansion valve box) (4 places)
Make sure to loosen the flare nut with holding the nut on pipe side with a spanner and giving
torque to the nut with another spanner in order to avoid unexpected stress to the copper pipe,
and then remove them. (Gas may come out at this time, but it is not abnormal.)
l Pay attention whether the flare nut pops out. (as the indoor unit is sometimes pressured.)
2. Make a flare on liquid pipe and gas pipe, and connect the refrigeration pipes on the indoor unit.
 Make sure to connect the liquid pipe between the heat exchanger and expansion valuve box
(indicated in Section A of the figure).
 Pipes can be take out in 2 directions, from the rear and from the floor.
 Use the provided joint pipes to connect gas pipes. Connect in the direction that the pipe will be
removed.
Bend the pipe with as big radius as possible and do not bend the pipe repeatedly. In addition, do
not twist and crush the pipes.
Do a flare connection as follows:
l Make sure to loosen the flare nut with holding the nut on pipe side with a spanner and giving
torque to the nut with another spanner in order to avoid unexpected stress to the copper pipe,
and then remove them.
l When fastening the flare nut, align the refrigeration pipe with the center of flare nut, screw the nut
for 3-4 times by hand and then tighten it by spanner with the specified torque mentioned in the
table below. Make sure to hold the pipe on the indoor unit securely by a spanner when tightening
the nut in order to avoid unexpected stress on the copper pipe.
3. Cover the flare connection part of the indoor unit with attached insulation material after a gas
leakage inspection, and tighten both ends with attached straps.
l Make sure to insulate both gas pipes and liquid pipes completely.
Incomplete insulation may cause dew condensation or water dropping.
4. Refrigerant is charged in the outdoor unit
As for the additional refrigerant charge for the indoor unit and piping, refer to the installation manual
attached to the outdoor unit.
Pipe diameter Tightening torque N·m
6.35 14 to 18
9.52 34 to 42
12.7 49 to 61
15.88 68 to 82
19.05 100 to 120
 There are "System name" and "Refrigerant amount" columns on the name plate of the outdoor unit.
Write the system name and the amount of the refrigerant in the columns.
Remote controller installation section
Control box
Air filter
170
- -
Strap (Accessory) Pipe cover (Accessory)
The thickness of insulation should be 20mm or more.
Expansion valve tube
Gas pipe connecting
point (Accessory)
Drain pipe
(Accessory)
Liquid pipe connecting point
Flexible tube
PT20A screws
D
6
Caution
Insert the
clamp an
l Instal
Imper
l Do no
inflam
dama
cause
l Conn
l Insula
l Check
the dr
l Make
or trap
out pr
maint
l Insert
l Tighte
Des
Drain te
l After
leaka
l Do dr
W
7
l Electr
install
to the
Be su
l Use s
to app
l Do no
misco
l Be su
l For th
1. Remo
2. Hold e
3. Fix th
4. Instal
Power so
Indoor po
Re