Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 152

④Installation of indoor unit (continued)
6. Make sure to install the indoor unit horizontally. Confirm the
levelness of the indoor unit with a level gauge or transpar-
ent hose filled with water. Keep the height difference at
both ends of the indoor unit within 3mm.
7. Tighten four upper nuts and fix the unit after height and
levelness adjustment.
Caution
●Do not adjust the height by adjusting upper nuts. It will cause unexpected stress on the indoor
unit and it will lead to deformation of the unit, failure of attaching a panel.
●Make sure to install the indoor unit horizontally and set the gap between the unit underside and
the ceiling plane properly. Improper installation may cause air leakage, dew condensation,
water leakage and noise.
●Make sure there is no gap between decoration panel and ceiling surface, and between decora-
tion panel and the indoor unit. The gap may cause air leakage, dew condensation and water
leakage.
●In case decorative panel is not installed at the same time, or ceiling material is installed after
the unit installed, avoid dust coming into the indoor unit.
⑤The indoor unit change procedure for duct type
Prepare a duct panel.
(1) Drill hole for duct
① While referring to the dimensions, cut the insulation.
② Cut sheet metal for the hole, and drill hole.
③ Install the duct joint with screws attached to the panel.
④ Install the bottom plate with screws attached to the panel.
[Upward]
40 40 45 120 120 45 40 40
Outlet
20 150 150 150 20
30 490 30
⑤ Set up as follows:
Changing the fan tap
Change the fan tap to the high speed by the remote controller.
[Method]
① Stop the operation of air conditioner. Press
for 3 seconds at the same time.
② Select " " (Indoor Unit Function) and press
③ Select " " (Fan Speed Setting) of No."02" and press
④ Select " " (High Fan Speed 1) and press
⑤ Press button to exit.
As for details, refer to the installation manual of remote controller.
CATEGORY NUMBER FUNCTION
02
Invalidating the louver switch
Invalidate the louver switch by the remote controller.
[Method]
① Stop the operation of air conditioner. Press
for 3 seconds at the same time.
② Select " " (Remote Controller Function) and press
③ Select " " (Louver Switch Setting) of No. "07" and press
④ Select " " (Louver Switch Invalid) and press
⑤ Press button to exit.
As for details, refer to the installation manual of remote controller.
CATEGORY NUMBER FUNCTION
07
(2) Duct work
Selling surface
Air supply
Request
●Calculate air flow and the static pressure to select the duct's length and shape.
Indoor unit
Hose
Duct joint
C
C
C
C
Cut.
C
C
C
C
C
C
C
C C
C
C
C
C
C
C
C
C
Control Box
Bottom plate
(SET) button and (MODE) button
(SET) button.
(SET) button.
(SET) button.
SETTING
(SET) button and (MODE) button
(SET) button.
(SET) button.
(SET) button.
SETTING
Indoor unit
Insulate duct
Air return
Supply air duct
(Prepare on site)
⑤The indoor unit change procedure for duct type (continued)
Caution
●Take care that the static pressure does not exceed 30 Pa.
The indoor unit has condensation owing to the decrease of air flow, may
cause wetting the ceiling and household goods.
Request
●The duct should be minimum bends. (Make the bend radius as
large as possible.)
●Conduct the duct work before ceiling attachment.
Bad example Bad example
(3) Connecting duct for outside air intake
① Outside air intake
●Use the intake, which is easier for work, either at the rear or the side.
② Duct connection
●Connect the 125 mm diameter duct, using the duct flange for 125mm diameter duct. (Clamp with
band)
●Insulate the duct to prevent condensation.
⑥Refrigerant pipe
Caution
●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.
●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.
●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.
●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.
●Use special tools for R410 refrigerant.
Work procedure
1. Remove the flare nut and blind flanges on the pipe of the indoor unit.
※ 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.)
● 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.
※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:
● 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.
● 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.
●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
φ 6.35
φ 9.52
φ 12.7
φ 15.88
φ 19.05
⑦Drain pipe
Caution
● Install the drain pipe according to the installation manual in order to drain properly.
Imperfection in draining may cause flood indoors and wetting the household goods, etc.
Do not put the drain pipe directly into the ditch where toxic gas such as sulfur, the other harmful and
●
inflammable gas is generated. Toxic gas would flow into the room and it would cause serious
damage to user's health and safety (some poisoning or deficiency of oxygen). In addition, it may
cause corrosion of heat exchanger and bad smell.
● Connect the pipe securely to avoid water leakage from the joint.
● Insulate the pipe properly to avoid condensation drop.
● Check if the water can flow out properly from both the drain outlet on the indoor unit and the end
of the drain pipe after installation.
● Make sure to make descending slope of greater than 1/100 and do not make up-down bend and/or trap
in the midway. In addition, do not put air vent on the drain pipe. Check if water is drained out properly
from the pipe during commissioning. Also, keep sufficient space for inspection and maintenance.
149
- -
50
40
30
20
10
Good example
0
Strap (Accessory)
14 to 18
34 to 42
49 to 61
68 to 82
100 to 120 The thickness of insulation should be 20mm or more.
Drain soc
High
Low
6.5 7 7.5 7.8
Air flow (m 3 /min)
Insulat
Pipe cover (Accessory)
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