Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 159

⑦Drain pipe (continued)
3. Make sure to make descending slope of greater than 1/100 and do not make up-down bend
and/or trap in the midway.
●Pay attention not to give stress on the pipe on the indoor unit side, and support and fix
the pipe as close place to the unit as possible when connecting the drain pipe.
●Do not set up air vent.
Supporting metal
1.5m~2m
Air vent
Insulation material
Descending slope greater than 1/100
●When sharing a drain pipe for more than
one unit, lay the main pipe 100mm
below the drain outlet of the unit. In
addition, select VP-30 or bigger size for
main drain pipe.
4. Insulate the drain pipe.
● Be sure to insulate the drain socket and rigid PVC pipe installed indoors otherwise it may
cause dew condensation and water leakage.
※ After drainage test implementation, cover the drain socket part with pipe cover (small size), then
use the pipe cover (big size) to cover the pipe cover (small size), clamps and part of the drain
hose, and fix and wrap it with tapes to wrap and make joint part gapless.
Caution
When the duct is connected and the blowing device is operated, the pressure inside the unit
becomes negative to the atmospheric pressure.
Pressure loss in the
suction side 100 Pa
Duct
Air filter
Suction grill
Drain pipe
Example: As shown in the above illustration, if the pressure loss of the suction grill, air filter,
and the suction side of the duct is 100 Pa, the drain water level during operation is
10mm higher than when it is not operating.
Fixing Traps
The pressure loss varies depending on the clogging in the air filter. Therefore, make one trap
(during the piping work) to prevent water from remaining in the drain pan. It is necessary to
make a trap with a structure that allows cleaning. Use the T joint as demonstrated in the left
illustration. Also, set the trap height as shown in the left illustration. Arrange the trap near to
the unit.
●Make one trap along the drain pipe as the left
Indoor unit
illustration.
H1 = 100 mm or the static pressure of the blowing device
H2 = 1/2 H1 or 50 ～ 100 mm
Drain test
Upon completion of drain piping, check by running water through it.
○Remove the side panel and gradually pour 1000 cc of water into the drain pan. Ensure
that the water drains smoothly.
Also, ensure that there are no water leaks from the connections and joints.
Trapped air will
No bump
generate noises.
No trap
Not touching the water
As wide as possible
(about100mm)
VP-30 or bigger
Descending slope greater than 1/100
Duct
Operating
Not Operating
Drain pan
⑧Wiring-out position and wiring connection
● Electrical installation work must be performed according to the installation manual by an
electrical installation service provider qualified by a power provider of the country, and be
executed according to the technical standards and other regulations applicable to electrical
installation in the country.
Be sure to use an exclusive circuit.
● Use specified cord, fasten the wiring to the terminal securely, and hold the cord securely in
order not to apply unexpected stress on the terminal.
● Do not put both power source line and signal line on the same route. It may cause miscommu-
nication and malfunction.
● Be sure to do D type earth work.
● For the details of electrical wiring work, see attached instruction manual for electrical wiring
work.
1. Remove a lid of the control box (2 screws) and a hook which is located on top of it.
2. Hold each wiring inside the unit and fasten them to terminal block securely.
3. Fix the wiring with clamps.
4. Install the removed parts back to original place.
Power source side
terminal block
Earth
Single unit wiring connection
Power source side Signal side
terminal block terminal block
L N
L N
Earth
Multi unit wiring connection
⑨Check list after installation
●Check the following items after all installation work completed.
Check if
The indoor and outdoor units are fixed securely?
Inspection for leakage is done?
Insulation work is properly done?
Water is drained properly?
Supply voltage is same as mentioned in the model name plate?
There is mis-wiring or mis-connection of piping?
Earth wiring is connected properly?
Cable size comply with specified size?
Any obstacle blocks airflow on air inlet and outlet?
156
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Signal side
terminal block
Remote Controller line
Inner/outer
Power source line clamp
connecting line
Earth
(Shielded cord)
Signal line
(Shielded cord)
Remote controller
Indoor power
line
source line
Power source line clamp
Expected trouble
Falling, vibration, noise
Insufficient capacity
Water leakage
Water leakage
PCB burnt out, not working at all
PCB burnt out, not working at all
Electric shock
PCB burnt out, not working at all
Insufficient capacity
PJD012D036
Check