Daikin FVXG25K2V1B User manual

Service
Manual
[Applied Models]
OInverter Pair : Heat Pump
Inverter Pair
Floor Standing Type K-Series
SiBE061121

SiBE061121
iTable of Contents
Inverter Pair
Floor Standing Type
K-Series
zHeat Pump
Indoor Unit
FVXG25K2V1B
FVXG35K2V1B
FVXG50K2V1B
Outdoor Unit
RXG25K2V1B
RXG35K2V1B
RXG50K2V1B

SiBE061121
Table of Contents ii
1. Introduction ............................................................................................ vi
1.1 Safety Cautions ....................................................................................... vi
1.2 Used Icons ...............................................................................................x
Part 1 List of Functions ................................................................ 1
1. Functions.................................................................................................2
Part 2 Specifications .................................................................... 3
1. Specifications ..........................................................................................4
Part 3 Printed Circuit Board Connector Wiring Diagram ............. 6
1. Indoor Unit...............................................................................................7
2. Outdoor Unit..........................................................................................10
2.1 RXG25/35K2V1B ...................................................................................10
2.2 RXG50K2V1B ........................................................................................12
Part 4 Function and Control........................................................ 14
1. Main Functions......................................................................................15
1.1 Temperature Control ..............................................................................15
1.2 Frequency Principle................................................................................15
1.3 Airflow Direction Control.........................................................................17
1.4 Fan Speed Control for Indoor Unit .........................................................18
1.5 RADIANT Operation...............................................................................19
1.6 Program Dry Operation ..........................................................................21
1.7 Automatic Operation...............................................................................22
1.8 Thermostat Control.................................................................................23
1.9 NIGHT SET Mode ..................................................................................24
1.10 ECONO Operation .................................................................................25
1.11 Inverter POWERFUL Operation .............................................................26
1.12 Other Functions......................................................................................27
2. Function of Thermistor ..........................................................................29
3. Control Specification .............................................................................30
3.1 Mode Hierarchy ......................................................................................30
3.2 Frequency Control..................................................................................31
3.3 Controls at Mode Changing / Start-up....................................................33
3.4 Discharge Pipe Temperature Control.....................................................35
3.5 Input Current Control..............................................................................36
3.6 Freeze-up Protection Control .................................................................37
3.7 Heating Peak-cut Control .......................................................................37
3.8 Outdoor Fan Control...............................................................................38
3.9 Liquid Compression Protection Function................................................38
3.10 Defrost Control .......................................................................................39
3.11 Outdoor Electronic Expansion Valve Control .........................................40
3.12 Malfunctions ...........................................................................................43
Part 5 Operation Manual ............................................................. 44
1. System Configuration............................................................................45
2. Operation Manual..................................................................................46

SiBE061121
iii Table of Contents
2.1 Names of Parts.......................................................................................46
2.2 Preparation before Operation.................................................................50
2.3 AUTO · DRY · COOL · HEAT · FAN Operation ......................................52
2.4 RADIANT Operation...............................................................................53
2.5 Temperature Setting...............................................................................54
2.6 Adjusting the Airflow Direction and Rate ................................................55
2.7 POWERFUL Operation ..........................................................................57
2.8 OUTDOOR UNIT QUIET Operation.......................................................58
2.9 ECONO Operation .................................................................................59
2.10 OFF TIMER Operation ...........................................................................60
2.11 ON TIMER Operation .............................................................................61
2.12 WEEKLY TIMER Operation ...................................................................62
2.13 Quick Reference.....................................................................................68
Part 6 Service Diagnosis............................................................. 69
1. Troubleshooting with LED .....................................................................71
1.1 Indoor Unit..............................................................................................71
1.2 Outdoor Unit ...........................................................................................71
2. Problem Symptoms and Measures .......................................................72
3. Service Check Function ........................................................................73
4. Troubleshooting ....................................................................................76
4.1 Error Codes and Description ..................................................................76
4.2 Indoor Unit PCB Abnormality .................................................................77
4.3 Freeze-up Protection Control or Heating Peak-cut Control....................79
4.4 Fan Motor (DC Motor) or Related Abnormality.......................................81
4.5 Radiant Panel Temperature Rise, Indoor Electronic Expansion Valve
(Motor Operated Valve) Abnormality, Freeze-up Protection Control......83
4.6 Thermistor or Related Abnormality (Indoor Unit)....................................85
4.7 Signal Transmission Error (between Indoor Unit and Outdoor Unit) ......86
4.8 Unspecified Voltage (between Indoor Unit and Outdoor Unit) ...............88
4.9 Outdoor Unit PCB Abnormality...............................................................89
4.10 OL Activation (Compressor Overload) ...................................................91
4.11 Compressor Lock ...................................................................................92
4.12 DC Fan Lock ..........................................................................................93
4.13 Input Overcurrent Detection ...................................................................94
4.14 Four Way Valve Abnormality..................................................................95
4.15 Discharge Pipe Temperature Control.....................................................97
4.16 High Pressure Control in Cooling ...........................................................98
4.17 Compressor System Sensor Abnormality ..............................................99
4.18 Position Sensor Abnormality ................................................................101
4.19 DC Voltage / Current Sensor Abnormality (25/35 Class) .....................104
4.20 CT or Related Abnormality (50 Class)..................................................105
4.21 Thermistor or Related Abnormality (Outdoor Unit)...............................107
4.22 Electrical Box Temperature Rise..........................................................109
4.23 Radiation Fin Temperature Rise ..........................................................111
4.24 Output Overcurrent Detection ..............................................................113
4.25 Refrigerant Shortage ............................................................................115
4.26 Low-voltage Detection or Over-voltage Detection................................118
4.27 Signal Transmission Error on Outdoor Unit PCB (50 Class Only) .......120
5. Check ..................................................................................................121
5.1 Thermistor Resistance Check ..............................................................121

SiBE061121
Table of Contents iv
5.2 Fan Motor Connector Check ................................................................122
5.3 Power Supply Waveforms Check.........................................................122
5.4 Electronic Expansion Valve Coil Check ...............................................123
5.5 Four Way Valve Performance Check ...................................................124
5.6 Inverter Unit Refrigerant System Check...............................................124
5.7 “Inverter Checker” Check .....................................................................125
5.8 Rotation Pulse Check on the Outdoor Unit PCB ..................................127
5.9 Installation Condition Check.................................................................128
5.10 Discharge Pressure Check...................................................................128
5.11 Outdoor Fan System Check .................................................................129
5.12 Main Circuit Short Check......................................................................129
5.13 Capacitor Voltage Check......................................................................130
5.14 Power Module Check ...........................................................................130
Part 7 Removal Procedure ........................................................ 131
1. Indoor Unit...........................................................................................132
1.1 Removal of Front Panel........................................................................132
1.2 Removal of Air Filters ...........................................................................133
1.3 Removal of Front Grille ASSY..............................................................134
1.4 Removal of Electrical Box / PCBs ........................................................135
1.5 Removal of Horizontal Blade................................................................148
1.6 Removal of Swing Motor ......................................................................149
1.7 Removal of Radiant Panel....................................................................150
1.8 Removal of Air Outlet ASSY.................................................................155
1.9 Removal of Drain Pan / Indoor Heat Exchanger ASSY........................157
1.10 Removal of Fan Rotor / Fan Motor.......................................................162
2. Outdoor Unit - RXG25/35K2V1B.........................................................167
2.1 Removal of Outer Panels / Fan Motor..................................................167
2.2 Removal of Electrical Box ....................................................................176
2.3 Removal of PCBs .................................................................................179
2.4 Removal of Reactor / Partition Plate ....................................................187
2.5 Removal of Sound Blankets .................................................................189
2.6 Removal of Four Way Valve.................................................................191
2.7 Removal of Compressor.......................................................................194
3. Outdoor Unit - RXG50K2V1B..............................................................196
3.1 Removal of Outer Panels .....................................................................196
3.2 Removal of Outdoor Fan / Fan Motor...................................................200
3.3 Removal of Electrical Box ....................................................................204
3.4 Removal of PCBs .................................................................................209
3.5 Removal of Sound Blankets / Thermistors ...........................................212
3.6 Removal of Four Way Valve.................................................................214
3.7 Removal of Outdoor Electronic Expansion Valve.................................215
3.8 Removal of Compressor.......................................................................216
Part 8 Trial Operation and Field Settings................................. 219
1. Pump Down Operation........................................................................220
2. Forced Cooling Operation ...................................................................221
3. Trial Operation ....................................................................................223
4. Field Settings ......................................................................................224
4.1 When 2 Units are Installed in 1 Room..................................................224

SiBE061121
vTable of Contents
4.2 Standby Electricity Saving....................................................................225
4.3 Jumper and Switch Settings.................................................................225
5. Application of Silicon Grease to a Power Transistor and
a Diode Bridge ....................................................................................226
Part 9 Appendix......................................................................... 227
1. Piping Diagrams..................................................................................228
1.1 Indoor Unit............................................................................................228
1.2 Outdoor Unit .........................................................................................229
2. Wiring Diagrams..................................................................................230
2.1 Indoor Unit............................................................................................230
2.2 Outdoor Unit .........................................................................................231

SiBE061121 Introduction
vi
1. Introduction
1.1 Safety Cautions
Cautions and
Warnings
Be sure to read the following safety cautions before conducting repair work.
The caution items are classified into “ Warning” and “ Caution”. The “ Warning”
items are especially important since they can lead to death or serious injury if they are not
followed closely. The “ Caution” items can also lead to serious accidents under some
conditions if they are not followed. Therefore, be sure to observe all the safety caution items
described below.
About the pictograms
This symbol indicates the item for which caution must be exercised.
The pictogram shows the item to which attention must be paid.
This symbol indicates the prohibited action.
The prohibited item or action is shown in the illustration or near the symbol.
This symbol indicates the action that must be taken, or the instruction.
The instruction is shown in the illustration or near the symbol.
After the repair work is complete, be sure to conduct a test operation to ensure that the
equipment operates normally, and explain the cautions for operating the product to the
customer.
1.1.1 Cautions Regarding Safety of Workers
Warning
Be sure to disconnect the power cable plug from the plug socket before
disassembling the equipment for repair.
Working on the equipment that is connected to the power supply may cause an
electrical shock.
If it is necessary to supply power to the equipment to conduct the repair or
inspecting the circuits, do not touch any electrically charged sections of the
equipment.
If the refrigerant gas is discharged during the repair work, do not touch the
discharged refrigerant gas.
The refrigerant gas may cause frostbite.
When disconnecting the suction or discharge pipe of the compressor at the
welded section, evacuate the refrigerant gas completely at a well-ventilated
place first.
If there is gas remaining inside the compressor, the refrigerant gas or
refrigerating machine oil discharges when the pipe is disconnected, and it may
cause injury.
If the refrigerant gas leaks during the repair work, ventilate the area. The
refrigerant gas may generate toxic gases when it contacts flames.
The step-up capacitor supplies high-voltage electricity to the electrical
components of the outdoor unit.
Be sure to discharge the capacitor completely before conducting repair work.
A charged capacitor may cause an electrical shock.
Do not start or stop the air conditioner operation by plugging or unplugging the
power cable plug.
Plugging or unplugging the power cable plug to operate the equipment may
cause an electrical shock or fire.

Introduction SiBE061121
vii
Be sure to wear a safety helmet, gloves, and a safety belt when working at a
high place (more than 2 m). Insufficient safety measures may cause a fall
accident.
In case of R-410A refrigerant models, be sure to use pipes, flare nuts and tools
for the exclusive use of the R-410A refrigerant.
The use of materials for R-22 refrigerant models may cause a serious accident
such as a damage of refrigerant cycle as well as an equipment failure.
Warning
Caution
Do not repair the electrical components with wet hands.
Working on the equipment with wet hands may cause an electrical shock.
Do not clean the air conditioner by splashing water.
Washing the unit with water may cause an electrical shock.
Be sure to provide the grounding when repairing the equipment in a humid or
wet place, to avoid electrical shocks.
Be sure to turn off the power switch and unplug the power cable when cleaning
the equipment.
The internal fan rotates at a high speed, and may cause injury.
Be sure to conduct repair work with appropriate tools.
The use of inappropriate tools may cause injury.
Be sure to check that the refrigerating cycle section has cooled down enough
before conducting repair work.
Working on the unit when the refrigerating cycle section is hot may cause
burns.
Use the welder in a well-ventilated place.
Using the welder in an enclosed room may cause oxygen deficiency.

SiBE061121 Introduction
viii
1.1.2 Cautions Regarding Safety of Users
Warning
Be sure to use parts listed in the service parts list of the applicable model and
appropriate tools to conduct repair work. Never attempt to modify the
equipment.
The use of inappropriate parts or tools may cause an electrical shock,
excessive heat generation or fire.
If the power cable and lead wires have scratches or deteriorated, be sure to
replace them.
Damaged cable and wires may cause an electrical shock, excessive heat
generation or fire.
Do not use a joined power cable or extension cable, or share the same power
outlet with other electrical appliances, since it may cause an electrical shock,
excessive heat generation or fire.
Be sure to use an exclusive power circuit for the equipment, and follow the local
technical standards related to the electrical equipment, the internal wiring
regulations, and the instruction manual for installation when conducting
electrical work.
Insufficient power circuit capacity and improper electrical work may cause an
electrical shock or fire.
Be sure to use the specified cable for wiring between the indoor and outdoor
units. Make the connections securely and route the cable properly so that there
is no force pulling the cable at the connection terminals.
Improper connections may cause excessive heat generation or fire.
When wiring between the indoor and outdoor units, make sure that the terminal
cover does not lift off or dismount because of the cable.
If the cover is not mounted properly, the terminal connection section may cause
an electrical shock, excessive heat generation or fire.
Do not damage or modify the power cable.
Damaged or modified power cable may cause an electrical shock or fire.
Placing heavy items on the power cable, and heating or pulling the power cable
may damage the cable.
Do not mix air or gas other than the specified refrigerant (R-410A / R-22) in the
refrigerant system.
If air enters the refrigerating system, an excessively high pressure results,
causing equipment damage and injury.
If the refrigerant gas leaks, be sure to locate the leaking point and repair it
before charging the refrigerant. After charging refrigerant, make sure that there
is no refrigerant leak.
If the leaking point cannot be located and the repair work must be stopped, be
sure to perform pump-down and close the service valve, to prevent the
refrigerant gas from leaking into the room. The refrigerant gas itself is
harmless, but it may generate toxic gases when it contacts flames, such as fan
and other heaters, stoves and ranges.
When relocating the equipment, make sure that the new installation site has
sufficient strength to withstand the weight of the equipment.
If the installation site does not have sufficient strength and if the installation
work is not conducted securely, the equipment may fall and cause injury.

Introduction SiBE061121
ix
Check to make sure that the power cable plug is not dirty or loose, then insert
the plug into a power outlet securely.
If the plug has dust or loose connection, it may cause an electrical shock or fire.
Be sure to install the product correctly by using the provided standard
installation frame.
Incorrect use of the installation frame and improper installation may cause the
equipment to fall, resulting in injury.
For unitary type
only
Be sure to install the product securely in the installation frame mounted on the
window frame.
If the unit is not securely mounted, it may fall and cause injury.
For unitary type
only
When replacing the coin battery in the remote controller, be sure to dispose of
the old battery to prevent children from swallowing it.
If a child swallows the coin battery, see a doctor immediately.
Warning
Caution
Installation of a leakage breaker is necessary in some cases depending on the
conditions of the installation site, to prevent electrical shocks.
Do not install the equipment in a place where there is a possibility of
combustible gas leaks.
If the combustible gas leaks and remains around the unit, it may cause a fire.
Check to see if the parts and wires are mounted and connected properly, and
if the connections at the soldered or crimped terminals are secure.
Improper installation and connections may cause excessive heat generation,
fire or an electrical shock.
If the installation platform or frame has corroded, replace it.
Corroded installation platform or frame may cause the unit to fall, resulting in
injury.
Check the grounding, and repair it if the equipment is not properly grounded.
Improper grounding may cause an electrical shock.