Daikin 2MXS18NMVJU User manual

REMOVAL
PROCEDURE
SERVICE MANUAL
18000/24000/36000 Btu/h Class
Outdoor Unit
Inverter
Multi Type
Si121558EA

Service Manual
Removal Procedure
Outdoor Unit
zHeat Pump
2MXS18NMVJU
3MXS24NMVJU
4MXS36NMVJU
2MXL18QMVJU
3MXL24QMVJU

Si121558EA
Removal Procedure 1
Table of Contents
1. Outer Panels ...........................................................................................2
2. Outdoor Fan / Fan Motor.........................................................................4
3. Right Side Panel / Electrical Box.............................................................6
4. PCBs .....................................................................................................11
5. Thermistor ASSYs.................................................................................16
6. Electronic Expansion Valve Coil ASSY.................................................18
7. Partition Plate / Sound Blankets............................................................19
8. Four Way Valve.....................................................................................21
9. Compressor...........................................................................................23
Note: The illustrations may be slightly different depending on the model.

Outer Panels Si121558EA
2Removal Procedure
1. Outer Panels
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 6 screws
and remove the top
panel.
2 Remove the 8 screws
of the front panel.
3 Slide the fan motor
fixing frame to the left
and unfasten the 2
hooks.
Top panel
(R22351)
Front panel
(R22278)
Hook
Fan motor fixing frame
(R22279)

Si121558EA Outer Panels
Removal Procedure 3
4
5
Unfasten the 2 hooks
on the right side.
Remove the front panel.
When reassembling, make
sure that the 2 hooks are
securely fastened.
6 Remove the 4 screws
of the discharge grille.
7 Unfasten the 2 hooks
and remove the
discharge grille.
When reassembling, make
sure that the 2 hooks are
securely fastened.
Step Procedure Points
Front panel
Hook
(R22280)
Discharge grille
(R22281)
Hook
(R22282)

Outdoor Fan / Fan Motor Si121558EA
4Removal Procedure
2. Outdoor Fan / Fan Motor
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 drip proof
cover.
2 Disconnect the
connector [S70].
[S70]: fan motor
When reassembling, put the
fan motor lead wire through
the back of the fan motor so
as not to be entangled with
the outdoor fan.
3 Release the fan motor
lead wire from the
groove and the hook.
Drip proof cover
(R22283)
[S70]
(R22284)
Lead wire Outdoor fan
(R3249)
Hook Groove
Fan motor lead wire
(R22285)

Si121558EA Outdoor Fan / Fan Motor
Removal Procedure 5
4 Remove the nut and
remove the outdoor fan.
Nut size: M8
When reassembling, align
the mark of the fan rotor
with the D-cut section of the
motor shaft.
5 Remove the 2 screws
and remove the fan
motor fixing frame.
When reassembling, fit the 2
lower hooks into the bottom
frame.
6 Unfasten the 3 hooks
on the fan motor fixing
frame and release the
fan motor lead wire.
7 Remove the 4 screws
and remove the fan
motor.
Step Procedure Points
Nut
D-cut
Outdoor fan
(R22286)
13 mm
(0.51 inch)
(R18965)
Fan motor fixing frame
(R22287)
Hook
(R20916)
Hook
Fan motor
lead wire
(R22288)
Fan motor (R22289)

Right Side Panel / Electrical Box Si121558EA
6Removal Procedure
3. Right Side Panel / Electrical Box
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 terminal
cover.
1 Remove the 2 screws
of the terminal cover.
2
3
Open the terminal cover
and pull down to
unfasten the 2 hooks.
Remove the terminal
cover.
When reassembling, make
sure that the 2 hooks are
securely fastened.
2. Remove the right side
panel.
When reassembling, make
sure that the 2 hooks are
securely fastened.
1 Slide the drip proof
plate up to unfasten the
2 hooks and remove it.
Terminal cover
(R22290)
Hook
(R22291)
Hook
Drip proof plate
(R22292)

Si121558EA Right Side Panel / Electrical Box
Removal Procedure 7
2 Remove the 19 screws
on the 5 terminal
boards and disconnect
the 4 connecting wires
(Room A, B, C, D) and
power supply wire.
3 Loosen the 5 lock nuts
and remove 5 conduits
together with the 4
connecting wires
(Room A, B, C, D) and
the power supply wire.
2-room model has no
connector for room C and D.
3-room model has no
connector for room D.
2-room model has no
conduit for room C and D.
3-room model has no
conduit for room D.
4
5
Remove the 3 screws.
Slide the stop valve
cover downward and
remove it.
When reassembling, make
sure to fit the 3 hooks.
6 Remove the 2 screws.
Step Procedure Points
Room A
Room C
Room D
Room B
Connecting wire
(Room A)
Connecting wire
(Room B)
Power supply
wire
Terminal board
power supply
Connecting wire
(Room C)
Connecting wire
(Room D)
(R22293)
Lock nut
Conduit
Conduit
Lock nut (R22294)
Stop valve cover
(R22295)
Hook
Hook (R22296)
(R22297)

Right Side Panel / Electrical Box Si121558EA
8Removal Procedure
7 Remove the 4 screws.
8
9
10
Release the outdoor
temperature thermistor
from the slit.
Remove the 3 screws.
Unfasten the 2 hooks
and remove the right
side panel.
Some models do not have a
slit for outdoor temperature
thermistor harness.
When reassembling, make
sure that the 2 hooks are
securely fastened.
3. Remove the electrical
box.
[S92]: gas pipe thermistor
[S93]: liquid pipe thermistor
1 Remove the 2
connectors for
thermistor.
Step Procedure Points
(R22298)
Right side panel
Slit Outdoor
temperature
thermistor
(R22299)
Hook
(R22300)
[S92][S93]
(R22301)

Si121558EA Right Side Panel / Electrical Box
Removal Procedure 9
2 Disconnect the 4
connectors for
electronic expansion
valve coil.
[S20] (white): room A
[S21] (red): room B
[S22] (blue): room C
[S23] (yellow): room D
2-room model does not have
[S22], [S23].
3-room model does not have
[S23].
3 Disconnect the
connector [S80] and
pull out the clamp.
[S80]: four way valve coil
4 Disconnect the
connector [S40].
[S40]: overload protector
5 Disconnect the relay
connector for
compressor.
Step Procedure Points
[S22]
[S21]
[S20]
[S23]
(R22302)
Clamp
[S80]
(R22303)
[S40]
(R22304)
Relay connector
(R22305)

Right Side Panel / Electrical Box Si121558EA
10 Removal Procedure
6 Pull out the clamp (1)
and cut the clamp (2).
7 Pull out the clamp at the
back of the electrical
box.
8 Remove the screw and
remove the electrical
box.
Step Procedure Points
Clamp (1)
Clamp (2)
(R23006)
Clamp
(R23007)
Electrical
box
(R22308)

Si121558EA PCBs
Removal Procedure 11
4. PCBs
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.
When reassembling, make
sure that the 2 hooks are
securely fastened.
1 Remove the screw and
remove the switch
cover.
2 Unfasten the 4 hooks
and remove the service
monitor PCB cover.
When reassembling, make
sure that the 4 hooks are
securely fastened.
3 Disconnect the 2
connectors [S501] and
[S502] from the service
monitor PCB.
[S501], [S502]: to main PCB
Switch cover
(R22309)
Hook
(R22310)
Hook
Hook
Service monitor
PCB cover
(R22311)
(R22312)
[S501] [S502]
Service monitor PCB (R22313)

PCBs Si121558EA
12 Removal Procedure
4 Unfasten the 4
projections and remove
the service monitor
PCB.
2. Remove the main PCB.
1 Remove the 2 screws.
2
3
Turn over the terminal
mounting plate.
Disconnect the 4
terminals for power
supply.
Before pulling out the
terminals, confirm the
terminal locations.
Step Procedure Points
Projection
Projection
Service
monitor PCB
(R22314)
(R22315)
Terminal for power supply
(R22316)
Black
BlueBrown
White (R22317)

Si121558EA PCBs
Removal Procedure 13
4 Cut the clamp and
disconnect the 2
terminals for room B
(black and white).
Before pulling out the
terminals, confirm the
terminal locations.
5 Pull out the 3 clamps.
6 Remove the earth /
ground screw.
Step Procedure Points
White
ClampBlack
(R22318)
Black White
(R22319)
Clamp
Clamp
(R23008)
Earth / ground screw
(R22321)

PCBs Si121558EA
14 Removal Procedure
7 Disconnect the
connector [S].
[S]: to terminal board
8 Cut the clamp.
9 Pull out the 4 clamps.
Step Procedure Points
[S]
(R22322)
Clamp
(R22323)
Clamp
Clamp (R22324)

Si121558EA PCBs
Removal Procedure 15
10 Remove the 8 screws.
11 Unfasten the 4 hooks
and remove the main
PCB.
Step Procedure Points
(R23078)
Hook (R22326)
Main PCB
(R22327)

Thermistor ASSYs Si121558EA
16 Removal Procedure
5. Thermistor ASSYs
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 thermistor
ASSY.
Be careful not to lose the clip
for the thermistor.
1 Cut the clamp and pull
out the outdoor heat
exchanger thermistor.
2 Open the sound blanket
(outer top) and sound
blanket (middle top)
and detach the
discharge pipe
thermistor.
Be careful not to lose the
fixture for the thermistor.
3 Remove the thermistor
ASSY.
Outdoor heat
exchanger
thermistor
Clamp
(R22328)
Clip
(R3264)
Discharge pipe
thermistor
Sound blanket
(middle top)
Sound blanket
(outer top)
(R22329)
Fixture
(R22352)
Thermistor ASSY
(R22330)

Si121558EA Thermistor ASSYs
Removal Procedure 17
2. Remove the gas pipe
thermistors ASSY.
The number of the gas pipe
thermistors varies depending
on the model.
Be careful not to lose the clip
of the thermistor.
1 Cut the 4 clamps and
pull out the 4 gas pipe
thermistors.
2 Remove the gas pipe
thermistor ASSY.
3. Remove the liquid pipe
thermistor ASSY.
The number of the liquid
pipe thermistors varies
depending on the model.
When reattaching the putty,
make sure there are no gap
between the connection
piping and putty.
Be careful not to lose the
fixture for the thermistor.
1 Remove the putty.
2 Pull out the 4 liquid pipe
thermistors and remove
the liquid pipe
thermistor ASSY.
Step Procedure Points
Gas pipe
thermistor
Clamp
(R22331)
Clip
(R22332)
Gas pipe thermistor ASSY
(R22333)
Putty
(R22334) Putty
Connection piping
(R22335)
Fixture
(R22337)
Liquid pipe
thermistor
(R22336)

Electronic Expansion Valve Coil ASSY Si121558EA
18 Removal Procedure
6. Electronic Expansion Valve Coil ASSY
Warning Be sure to wait for 10 minutes or more after turning off all power supplies before
disassembling work.
Be careful not to get yourself burnt with the pipes and other parts that are heated by
the gas brazing machine.
If the refrigerant gas leaks during work, ventilate the room. (If the refrigerant gas is
exposed to flames, toxic gas may be generated.)
Since it may happen that the refrigerant oil in the compressor catches fire, prepare wet
cloth so as to extinguish fire immediately.
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.
Restore the piping by non-oxidation brazing.
Note 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.
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.
Be careful so as not to burn the compressor terminals, the name plate, the outdoor
heat exchanger fin.
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.
Step Procedure Points
1 Pull out the 4 electronic
expansion valve coils.
The number of the electronic
expansion valve coils varies
depending on the model.
2 Remove the electronic
expansion valve coil
ASSY.
Electronic
expansion
valve coil
(R22338)
Electronic expansion
valve coil ASSY
(R22339)