Daikin 3MKD75BVMA8 User manual

REMOVAL
PROCEDURE
SERVICE MANUAL
5.8/6.8/7.1/7.5 kW Class
Outdoor Unit
Inverter
Multi Type
Si12-793

Service Manual
Removal Procedure
Outdoor Unit
zCooling Only zHeat Pump
3MKD75BVMA8 3MXD68BVMA8
2MKD58DVM 3MXS68EVMA
3MKD58DVM
3MKD75DVM
4MKD75DVM
4MKS71DVM
3MKS71ESG
3MKS75EVMA

Si12-793
Removal Procedure 1
Table of Contents
1. Removal of Outer Panels ........................................................................2
2. Removal of Electrical Box .......................................................................3
3. Removal of PCBs....................................................................................7
4. Removal of Fan Motor...........................................................................10
5. Removal of Sound Blankets..................................................................11
6. Removal of Coils / Thermistors .............................................................13
7. Removal of Four Way Valve / Defrost Solenoid Valve..........................15
8. Removal of Distributor...........................................................................17
9. Removal of Compressor .......................................................................18
Note: The illustrations may be slightly different depending on the model.
The illustrations are for heat pump models as representative.

Removal of Outer Panels Si12-793
2Removal Procedure
1. Removal of Outer Panels
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1External appearance
2Remove the 4 screws of
the top panel and the 6
screws of the front panel.
3Remove the 4 screws of
the discharge grille.
4Remove the 2 screws of
the piping cover.
(R2159)
Top panel
Discharge grille
Front panel (R10351)
(R10352)
Piping cover

Si12-793 Removal of Electrical Box
Removal Procedure 3
2. Removal of Electrical Box
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1. Remove the connecting
wires.
1The figure shows the
connecting wires.
2Remove the terminal
board fixing screw.
Match the colors of the
connection wires to A, B and
C ports as follows.
(1) Black: Power supply
(2) White: Power supply
(3) Red: Transmission
The wires are fixed to the
terminal board with screws.
Electrical box
Electronic expansion
valve coils
Service monitor PCB
A port
B port
C port
Service port
(R3063)
Outdoor temperature thermistor
Liquid
pipe
Gas pipe
(R2163)
Terminal board fixing screw
Power supply
(L)–White
(N)–Black
A port
Earth / ground
wire
Wire fixing plate
B port C port
(R17637)

Removal of Electrical Box Si12-793
4Removal Procedure
3Pull out the terminal
board to open.
Glass tube fuse and varistor
cannot be replaced
individually because lead-
free soldering is provided.
2. Remove the harnesses.
1Disconnect the
connectors for the
electronic expansion
valve coils. [S20] [S21]
[S22].
2Remove the connector
for the four way valve
coil [S80].
The cooling only models do
not have the harness for
[S80].
3Disconnect the
connectors for the
thermistors [S90] [S92]
[S93] and the connector
for the overload
protector [S40].
[S40]: Overload protector
[S90]: Thermistor
(outdoor temperature,
outdoor heat exchanger,
discharge pipe)
[S92]: Gas pipe thermistor
[S93]: Liquid pipe thermistor
Step Procedure Points
(R2165)
Varister
Glass tube fuse
Screw
Terminal
board
[S20] [S21] [S22]
(R16025)
(R11729)
[S80]
[S40]
(R2168)
[S90] [S92] [S93]

Si12-793 Removal of Electrical Box
Removal Procedure 5
4Disconnect the relay
connector of the
compressor.
5Remove the reactor
lead wires.
3. Remove the wire fixing
plate.
1Remove the 2 screws
of the wire fixing plate.
4. Remove the electrical
box.
1Remove the screw of
the electrical box.
Step Procedure Points
(R2169)
Reactor
(R2170)
(R11309)
Wire fixing
plate
(R2172)

Removal of Electrical Box Si12-793
6Removal Procedure
2Remove the screw of
the electrical box.
3Remove the drip proof
cover.
4Disconnect the
connector for the fan
motor [S70] from the
inverter PCB.
5Lift up the electrical box
and dismount it.
Step Procedure Points
(R2173)
Drip
proof
cover
(R2174)
Inverter PCB
[S70]
(R2175)
(R2176)

Si12-793 Removal of PCBs
Removal Procedure 7
3. Removal of PCBs
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1. Remove the service
monitor PCB and the
main PCB.
When reassembling, insert
the base bar into the hole of
the main PCB.
1Remove the screw of
the main PCB, and
unfasten the 2 hooks.
2Unfasten the hook of
the terminal board, and
open the terminal
board.
3Disconnect each
connector [S11] [HE]
[HL] [HN] on the back of
the terminal board.
4Disconnect the
connectors [S52]
[S102] from the service
monitor PCB.
Main PCB
(R2177)
Base bar
(R2178)
Hook
[S11] [HL] [HN]
(R17403)
[HE]
(R17347)
[S102]
[S52]
Service monitor PCB

Removal of PCBs Si12-793
8Removal Procedure
5Lift up the main PCB.
6Disconnect the
connectors [S31] [S32]
[S33] [S71] [H1] [H2].
7The figure shows the
main PCB.
Step Procedure Points
(R2181)
[S31] [S71] [S33] (R10362)
[H1] (yellow)
[S32]
[H2] (blue)
(R10363)
[S80]
[S21] [S20] [S40]
[S31]
[S71]
[S33]
[S32]
[H2]
[H1]
FU2 (3.15A)
[S90]
[S92]
[S93]
(R10356)

Si12-793 Removal of PCBs
Removal Procedure 9
8Unfasten the 2 hooks
and remove the service
monitor PCB.
2. Remove the inverter PCB
(MID2).
1Remove the 7 screws
and remove the inverter
PCB (MID2).
Step Procedure Points
Priority room setting switch
(SW4)
Wiring error check switch
(SW3)
Forced operation [ON/OFF]
switch (SW1)
NIGHT QUIET mode setting
switch (SW5)
Operation mode switch
(SW2)
Hook
Hook
(R17348)
LED A
LED 1
LED 2
LED 3
LED 4
FU201 (3.15A)
Inverter PCB
(MID2)
(R10355)

Removal of Fan Motor Si12-793
10 Removal Procedure
4. Removal of Fan Motor
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1Remove the nut and
remove the outdoor fan.
Preparation
Disconnect the connector for
the fan motor.
Nut size : M6
When reassembling, align
the mark of the outdoor
fan with the D-cut section of
the motor shaft.
When reassembling, fix the
fan motor lead wire to the
clamps to avoid contact with
the outdoor fan.
2Remove the 2 screws of
the fan motor mount.
3Disconnect the for motor
lead wire by releasing the
2 clamps fixing the wire.
Remove the 4 screws to
remove the fan motor.
(R10362)
10 mm
(R12236)
(R10363)
Fan
motor
mount
(Backside) Clamp
Fan motor (R5567)
(R5568)

Si12-793 Removal of Sound Blankets
Removal Procedure 11
5. Removal of Sound Blankets
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1Remove the 5 screws
of the right side panel.
2Release the clamp with
pliers.
Some models do not have
the clamp.
3Remove the 2 screws
of the partition plate,
and remove the plate.
Right side
panel
(R2191)
(R16508)
Partition plate
(R11311)

Removal of Sound Blankets Si12-793
12 Removal Procedure
4Remove the sound
blanket (top upper, top
inner, outer, inner).
Step Procedure Points
Sound blanket (top)
Sound blanket (top inner)
Sound blanket
(inner)
Sound blanket
(outer)
Carefully remove the sound
blanket, which is easily
torn in the piping section.
(R4765)

Si12-793 Removal of Coils / Thermistors
Removal Procedure 13
6. Removal of Coils / Thermistors
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1Remove the screw of
the four way valve coil.
Some models do not have a
four way valve coil.
2Remove the screw and
remove the defrost
solenoid valve coil.
3Remove the electronic
expansion valve coil for
each room.
4Release the fixture and
remove the discharge
pipe thermistor.
Place the thermistor so that
its end comes up to the end
of the fixture.
Be careful not to lose the
fixture for the discharge pipe
thermistor.
Four way
valve coil
(R2194)
Defrost
solenoid
valve coil
(R2195)
Electronic
expansion
valve coil
(R2196)
(R10367)
Fixture
Discharge pipe
thermistor
Fixture
(R10536)
Pipe
Thermistor

Removal of Coils / Thermistors Si12-793
14 Removal Procedure
5Peel off the putty and
pull out the thermistors.
Place the thermistor so that
its end comes up to the end
of the fixture.
Be careful not to lose the clip
or fixtures for the liquid and
gas pipe thermistor.
6Remove the wire
harness.
[S90]:
Outdoor temperature thermistor
(Blue)
Heat exchanger thermistor
(Gray)
Discharge pipe thermistor
(Black)
[S92]: Gas pipe thermistor
Room A (Black)
Room B (Gray)
Room C (Brown)
[S93]: Liquid pipe thermistor
Room A (Black)
Room B (Gray)
Room C (Yellow)
Step Procedure Points
(R2198)
Gas pipe thermistor
Liquid pipe
thermistor
(R2199)

Si12-793 Removal of Four Way Valve / Defrost Solenoid Valve
Removal Procedure 15
7. Removal of Four Way Valve / Defrost Solenoid
Valve
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1Remove the screw and
remove the four way
valve coil.
The cooling only models do
not have a four way valve
coil and a defrost solenoid
valve coil.
Warning
Be careful not to get yourself
burnt with the pipes and other
parts that are heated by the
gas brazing machine.
Warning
If the refrigerant gas leaks
during work, ventilate the
room. (If the refrigerant gas is
exposed to flames, toxic gas
may be generated.)
Caution
From the viewpoint of global
environment protection, do
not discharge the refrigerant
gas in the atmosphere. Make
sure to collect all the
refrigerant gas.
Cautions for restoration
1. Restore the piping by non-
oxidation brazing.
2. It is required to prevent the
carbonization of the oil inside
the four way valve and the
deterioration of the gaskets
affected by heat. (Keep
below 120°C.) For the sake
of this, wrap the four way
valve with wet cloth and
provide water so that the
cloth does not dry.
In case of difficulty with gas
brazing machine
1. Disconnect the brazed part
where is easy to disconnect
and restore.
2. Cut pipes on the main unit
with a tube cutter in order to
make it easy to disconnect.
2Remove the screw and
remove the defrost
solenoid valve coil.
Before working, make
sure that the refrigerant
gas is empty in the circuit.
Be sure to apply nitrogen
replacement when
heating up the brazed
part.
3Heat the 4 brazed
points of the four way
valve. Disconnect the
point (a) first.
4
5
Disconnect the points
(b) and (c).
Disconnect the point (d)
and remove the four
way valve.
(R10370)
Defrost solenoid
valve coil
Four way
valve coil
(a)
(R2201)
(R2202)
(c)
(d)
(b)

Removal of Four Way Valve / Defrost Solenoid Valve Si12-793
16 Removal Procedure
6Disconnect the 2
brazed points, first (e),
and then (f).
Remove the defrost
solenoid valve.
Note:
Do not use a metal saw for
cutting pipes by all means
because the sawdust comes
into the circuit.
When withdrawing the pipes,
be careful not to pinch them
firmly with pliers. The pipes
may get deformed.
Provide a protective sheet or
a steel plate so that the
brazing flame cannot
influence peripheries.
Step Procedure Points
(f)
(e)
(R12395)

Si12-793 Removal of Distributor
Removal Procedure 17
8. Removal of Distributor
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
Before working, make
sure that the refrigerant
gas is empty in the circuit.
Be sure to apply nitrogen
replacement when
heating up the brazed
part.
Warning
Be careful not to get yourself
burnt with the pipes and other
parts that are heated by the
gas brazing machine.
Warning
If the refrigerant gas leaks
during work, ventilate the
room. (If the refrigerant gas is
exposed to flames, toxic gas
may be generated.)
Caution
From the viewpoint of global
environment protection, do
not discharge the refrigerant
gas in the atmosphere. Make
sure to collect all the
refrigerant gas.
Cautions for restoration
1. Restore the piping by non-
oxidation brazing.
2. It is required to prevent the
carbonization of the oil inside
the four way valve and the
deterioration of the gaskets
affected by heat. (Keep
below 120°C.) For the sake
of this, wrap the four way
valve with wet cloth and
provide water so that the
cloth does not dry.
In case of difficulty with gas
brazing machine
1. Disconnect the brazed part
where is easy to disconnect
and restore.
2. Cut pipes on the main unit
with a tube cutter in order to
make it easy to disconnect.
1Remove the putty.
2Heat up and disconnect
the 5 brazed parts to
remove the distributor.
Note:
Do not use a metal saw
for cutting pipes by all
means because the
sawdust comes into the
circuit.
When withdrawing the
pipes, be careful not to
pinch them firmly with
pliers. The pipes may get
deformed.
Provide a protective sheet
or a steel plate so that the
brazing flame cannot
influence peripheries.
Brazed part
Distributor
Putty
Brazed
part
(R2204)

Removal of Compressor Si12-793
18 Removal Procedure
9. Removal of Compressor
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1
2
Remove the terminal
cover.
Disconnect the
compressor lead wires.
3Remove the 2 sheets of
putty.
4Remove the 3 nuts.
Terminal cover
Compressor lead wire
V (yellow) W (blue)
U (red)
N
(brown)
Terminal nameplate
(R16026)
(R2205)
Putty
(R10373)