Daikin RKN18NMVJU User manual

REMOVAL
PROCEDURE
SERVICE MANUAL
18000 Btu/h Class
Outdoor Unit
Inverter
Pair Type
Si001556E

Service Manual
Removal Procedure
Outdoor Unit
zCooling Only
RKN18NMVJU

Si001556E
Removal Procedure 1
Table of Contents
1. Outer Panels ...........................................................................................2
2. Outdoor Fan / Fan Motor.........................................................................4
3. Electrical Box ..........................................................................................7
4. PCB.......................................................................................................10
5. Thermistor ASSY / Partition Plate .........................................................12
6. Sound Blankets .....................................................................................16
7. Electronic Expansion Valve Coil / Compressor.....................................17

Outer Panels Si001556E
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
(R21871)
Front panel
(R21872)
Fan motor fixing frame
Hook
(R21873)

Si001556E Outer Panels
Removal Procedure 3
4
5
Unfasten the 2 hooks
on the right side.
Remove the front panel.
6 Remove the 4 screws
of the discharge grille.
7 Unfasten the 2 hooks
and remove the
discharge grille.
Step Procedure Points
Hook
Front panel
(R21874)
Discharge grille
(R20906)
Hook
Discharge grille
(R21875)

Outdoor Fan / Fan Motor Si001556E
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
3
Disconnect the
connector [S71].
Pull out the bottom
clamp of the fan motor
lead wire.
[S71]: fan motor
4 Release the fan motor
lead wire from the
groove.
Drip proof cover
(R21876)
[S71]
Clamp
Fan motor
lead wire
(R21877)
Groove
(R21878)

Si001556E Outdoor Fan / Fan Motor
Removal Procedure 5
5 Remove the nut and
remove the outdoor fan.
Nut size : M8
Align the mark of the
outdoor fan with the D-cut
section of the motor shaft
when reassembling.
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.
6 Remove the 2 screws
and remove the fan
motor fixing frame.
When reassembling, fit the 2
lower hooks into the bottom
frame.
Step Procedure Points
Nut Outdoor fan
(R21879)
13 mm
(0.51 inch)
(R18965)
Lead wire Outdoor fan
(R3249)
Fan motor fixing frame
(R21880)
Hook (R20916)

Outdoor Fan / Fan Motor Si001556E
6Removal Procedure
7 Unfasten the 3 hooks
on the fan motor fixing
frame and release the
fan motor lead wire.
8 Remove the 4 screws
and remove the fan
motor.
Step Procedure Points
Fan motor lead wire
Hook
(R21881)
Fan motor
(R21882)

Si001556E Electrical Box
Removal Procedure 7
3. 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 2 screws
of the terminal cover.
2
3
Open the terminal cover
and pull down to
unfasten the 2 hooks.
Remove the terminal
cover.
4
5
6
Remove the 7 screws
on the terminal board
and disconnect the
connecting wire and
power supply wire.
Loosen the 2 lock nuts
and remove the 2
conduits.
Remove the connecting
wire and power supply
wire.
Terminal cover
(R21883)
Hook
(R21884)
123
Connecting wire Power supply wire
Lock nut
Conduit
Terminal board
(R21885)

Electrical Box Si001556E
8Removal Procedure
7 Remove the 2 screws
and remove the conduit
mounting plate.
When reassembling, be sure
to fit the 2 hooks on the
conduit mounting plate to the
right side panel.
8 Remove the 2 screws.
9 Disconnect the
connector [S20].
[S20]: electronic expansion
valve coil
10 Disconnect the 2
connectors from the
reactor.
When reassembling, you
can reconnect the 2
connectors for the reactor in
either way regardless of the
color.
Step Procedure Points
Conduit
mounting
plate
(R21886)
(R21918)
Hook
(R21887)
[S20]
(R21888)
Connector Reactor
(R21889)

Si001556E Electrical Box
Removal Procedure 9
11 Disconnect the
connector [S40].
[S40]: overload protector
12 Disconnect the
connector [S30].
[S30]: compressor motor
13 Disconnect the
connector [S90] and
pull out the clamp.
[S90]: thermistors
14 Remove the screw and
remove the electrical
box.
Step Procedure Points
[S40]
(R21890)
[S30]
(R21891)
[S90] Clamp
(R21892)
Electrical box
(R21893)

PCB Si001556E
10 Removal Procedure
4. PCB
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 screw of
the terminal board.
2 Remove the earth /
ground screw and pull
out the clamp from the
mounting plate for
terminal board.
3 Remove the earth /
ground screw from the
electrical box.
Terminal board
(R21894)
Clamp Terminal board mounting plate
Earth / ground screw
(R21895)
Earth / ground screw
Electrical box
(R21896)

Si001556E PCB
Removal Procedure 11
4
5
Remove the 3 screws
of the PCB.
Unfasten the 2 spacers
and the 2 hooks to
remove the PCB.
A long screwdriver is
necessary for removing
these screws.
Step Procedure Points
Spacer
Spacer
Hook
HookPCB (R21897)
(R21898)

Thermistor ASSY / Partition Plate Si001556E
12 Removal Procedure
5. Thermistor ASSY / Partition Plate
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 screw of
the stop valve cover.
2 Slide the stop valve
cover downward and
remove it.
When reassembling, make
sure to fit the 3 hooks.
3 Release the outdoor
temperature thermistor
harness from the slit.
Stop valve
cover
(R21899)
Stop valve cover
(R21900)
Hook
Hook
(R21901)
SlitOutdoor temperature
thermistor
(R21902)

Si001556E Thermistor ASSY / Partition Plate
Removal Procedure 13
4 Remove the 4 screws
of the right side panel.
5 Unfasten the 4 hooks
and remove the right
side panel.
When reassembling, make
sure to fit all the hooks.
6 Pull out the outdoor
heat exchanger
thermistor and cut the
clamp.
Be careful not to lose the clip
for the thermistor.
Step Procedure Points
Right side
panel
(R21903)
Right side
panel
Hook
Hook
Hook
(R21904)
Hook
(R21317)
Outdoor heat exchanger thermistor
Clamp
(R21905)
Clip
(R20852)

Thermistor ASSY / Partition Plate Si001556E
14 Removal Procedure
7 Open the sound blanket
(top) and detach the
discharge pipe
thermistor.
Be careful not to lose the
fixture for the thermistor.
8 Remove the thermistor
ASSY.
9 Pull out the clamp.
10
11
12
Remove the 2 screws
of the reactor.
Slide the reactor
upward to unfasten the
2 hooks.
Remove the reactor.
Step Procedure Points
Discharge pipe thermistor
Sound blanket (top)
(R21906)
Fixture
(R20999)
Thermistor ASSY
(R21907)
Clamp
(R21908)
Reactor
Hook (R21909)

Si001556E Thermistor ASSY / Partition Plate
Removal Procedure 15
13 Remove the 2 screws
and remove the
partition plate.
When reassembling, fit the
lower hook into the bottom
frame.
Step Procedure Points
Partition plate
(R21910)
Hook Bottom frame (R20947)

Sound Blankets Si001556E
16 Removal Procedure
6. Sound Blankets
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 sound
blanket (top).
Since the piping ports on the
sound blanket are torn
easily, remove the blanket
carefully.
2 Open and pull up the
sound blanket (outer).
3 Remove the sound
blanket (inner).
(R21911)
Sound blanket
(top)
Sound blanket (outer)
(R21912)
Sound blanket (inner)
(R21913)

Si001556E Electronic Expansion Valve Coil / Compressor
Removal Procedure 17
7. Electronic Expansion Valve Coil / Compressor
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 electronic
expansion valve coil.
Electronic
expansion
valve coil
(R21914)

Electronic Expansion Valve Coil / Compressor Si001556E
18 Removal Procedure
2 Remove the terminal
cover.
3
4
Remove the protection
bushing.
Disconnect the
compressor lead wires
and the overload
protector.
5
6
7
8
Heat up the brazed part
of the discharge side
pipe and disconnect it.
Heat up the brazed part
of the suction side pipe
and disconnect it.
Remove the 3 nuts.
Lift up the compressor
and remove it.
Step Procedure Points
Terminal cover
(R21915)
Overload protector Protection bushing U (red)
V (yellow) W (blue) (R21916)
Nut
Brazed part of the
suction side pipe
Brazed part of the
discharge side pipe
(R21917)