Daikin SUPER MULTI NX 2MXS18GVJU User manual

REMOVAL
PROCEDURE
SERVICE MANUAL
7.1/8.0 kW Class
18000 Btu/h Class
Outdoor Unit
Inverter
Multi Type
Si12-994

Service Manual
Removal Procedure
Outdoor Unit
zHeat Pump
2MXS18GVJU
3MXS80EV2C
PMXS3GV2C

Si12-994
Removal Procedure 1
Table of Contents
1. Removal of Outer Panels ........................................................................2
2. Removal of Electrical Box (Pattern 1) .....................................................3
3. Removal of Electrical Box (Pattern 2) .....................................................7
4. Removal of PCBs (Pattern 1)................................................................12
5. Removal of PCBs (Pattern 2)................................................................16
6. Removal of Fan Motor...........................................................................19
7. Removal of Sound Blankets..................................................................20
8. Removal of Coils / Thermistors .............................................................22
9. Removal of Four Way Valve / Defrost Solenoid Valve..........................24
10.Removal of Distributor...........................................................................26
11.Removal of Compressor .......................................................................27
Note: The illustrations may be slightly different depending on the model.

Removal of Outer Panels Si12-994
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

Si12-994 Removal of Electrical Box (Pattern 1)
Removal Procedure 3
2. Removal of Electrical Box (Pattern 1)
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 (Pattern 1) Si12-994
4Removal Procedure
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].
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
4Disconnect the relay
connector of the
compressor.
Step Procedure Points
[S20] [S21] [S22]
(R16025)
(R11729)
[S80]
[S40]
(R2168)
[S90] [S92] [S93]
(R2169)

Si12-994 Removal of Electrical Box (Pattern 1)
Removal Procedure 5
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.
2Remove the screw of
the electrical box.
Step Procedure Points
Reactor
(R2170)
(R11309)
Wire fixing
plate
(R2172)
(R2173)

Removal of Electrical Box (Pattern 1) Si12-994
6Removal Procedure
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
Drip
proof
cover
(R2174)
Inverter PCB
[S70]
(R2175)
(R2176)

Si12-994 Removal of Electrical Box (Pattern 2)
Removal Procedure 7
3. Removal of Electrical Box (Pattern 2)
Procedure Warning Be sure to wait for 10 minutes or more after turning off all power
supplies before disassembling work.
Step Procedure Points
1. Disconnect the
connecting wires.
The US model has a
protection plate on the right
side panel.
Remove the 2 screws to
remove the protection plate.
1Remove the terminal
board fixing screw.
The wires are fixed to the
terminal board with screws.
2Remove all the screws
of the connecting wires
and the power supply
wires.
3Remove the screw of
the earth / ground wire.
2. Remove the harnesses. [S20]: White
[S21]: Red
Bundle the harnesses of the
electronic expansion valve
coil with clamp.
Pull out the clamp.
When reassembling, insert
the clamp into one of the
holes.
1Disconnect the 2
connectors for the
electronic expansion
valve coil [S20] [S21].
Liquid (room A)
Liquid (room B)
Gas (room A)
Gas (room B)
(R17343)
Electronic expansion
valve coil
Conduit
Lock nut
Conduit
mounting plate
Screw (R17395)
Protection plate
RoomARoomB
Terminal board fixing screw Power supply
Earth /
ground wire
(R18597)
[S20] [S21]
(R17400) For the electronic
expansion valve coil (R17396)

Removal of Electrical Box (Pattern 2) Si12-994
8Removal Procedure
2Disconnect the
connector for the four
way valve coil [S80].
When reassembling, insert
the clamp into the hole as
below.
3Disconnect the
connectors for the
thermistors [S90] [S92]
[S93] and the overload
protector [S40].
[S40]: overload protector
[S90]: thermistors
(outdoor temperature,
outdoor heat exchanger,
discharge pipe)
[S92]: gas pipe thermistors
[S93]: liquid pipe thermistors
Pull out the clamp.
When reassembling, insert
each clamp of the
thermistors into one of the
holes as below.
When reassembling, insert
each clamp into the holes.
When reassembling, the
thermistor harness should
be placed between the
electrical box and the reactor
harness as below.
Step Procedure Points
(R17398)
[S80]
Clamp
(R17397)
[S40]
[S90] [S92] [S93]
(R17399)
[S92]
[S93]
(R17401)
Reactor
harness
Thermistor
ASSY
(R17093)
Reactor harness
Thermistor
ASSY

Si12-994 Removal of Electrical Box (Pattern 2)
Removal Procedure 9
4Disconnect the relay
connector of the
compressor.
5Release the clamp with
pliers.
6Disconnect the reactor
lead wires.
Step Procedure Points
(R17065)
(R17066)
(R2170)
Reactor

Removal of Electrical Box (Pattern 2) Si12-994
10 Removal Procedure
3. Remove the electrical
box.
1Remove the screw of
the shield plate.
2Unfasten the 2 hooks
and remove the shield
plate.
3Remove the screw on
the right side of the
electrical box.
4Remove the screw on
the front side of the
electrical box.
Step Procedure Points
(R17345)
Shield plate
(R17346)
Hook
(R10361)
(R17402)

Si12-994 Removal of Electrical Box (Pattern 2)
Removal Procedure 11
5Remove the drip proof
cover.
6Disconnect the
connector for the fan
motor [S70] from the
inverter PCB (MID2).
Release the fan motor
lead wire from the
hooks.
7Remove the electrical
box.
Step Procedure Points
(R2174)
Drip proof cover
Inverter PCB (MID2)
[S70]
(R2175)
(R2176)

Removal of PCBs (Pattern 1) Si12-994
12 Removal Procedure
4. Removal of PCBs (Pattern 1)
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.
1Remove the screw of
the main PCB, and
release the 2 hooks.
2Remove the screw and
release the hook of the
terminal board, and
open the terminal
board.
3Disconnect each
connector on the back
of the terminal board.
4Detach the fixing tape
for the drip proof plate.
Main PCB
Base bar
(R2177)
(R11731)
Terminal board
Hook
(R6575)
(R6576)
Fixing tape

Si12-994 Removal of PCBs (Pattern 1)
Removal Procedure 13
5Remove the drip proof
plate.
6Disconnect the
connectors [S52]
[S102] from the service
monitor PCB.
7The figure shows the
service monitor PCB.
8Release the 2 hooks to
remove the service
monitor PCB.
Step Procedure Points
(R6577)
Drip proof plate
(R6578)
[S102]
[S52]
Service
monitor PCB
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)
LED A
LED 1
LED 2
LED 3
LED 4
(R3064)
(R6579)
Hook
Hook

Removal of PCBs (Pattern 1) Si12-994
14 Removal Procedure
9Remove the service
monitor PCB.
10 Lift up the main PCB.
11 Disconnect the
connectors [S31] [S32]
[S33] [S71] [H1] [H2].
Step Procedure Points
(R6580)
Main PCB
(R2181)
[S31] [S71] [S33] (R10362)
[H1] (yellow)
[S32]
[H2] (blue)
(R10363)

Si12-994 Removal of PCBs (Pattern 1)
Removal Procedure 15
12 Disconnect the
connector [E].
13 The figure shows the
main PCB.
2. Remove the inverter PCB
(MID2).
1Remove the 7 screws
to remove the inverter
PCB (MID2).
Step Procedure Points
[E] (green/yellow)
(R2184)
[H1]
[H2]
[S22]
[S80]
[S21] [S20] [S40] (R11310)
[S31]
[S33]
[S32]
[S90]
[S92]
[S93] FU2
[S71]
Fuse (3.15A)
Inverter
PCB
(R10355)

Removal of PCBs (Pattern 2) Si12-994
16 Removal Procedure
5. Removal of PCBs (Pattern 2)
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

Si12-994 Removal of PCBs (Pattern 2)
Removal Procedure 17
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)

Removal of PCBs (Pattern 2) Si12-994
18 Removal Procedure
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)