Please file and use this manual together with the service manual for Model No. CS-E9NKKW CS-E12NKKW, Order No.
PHAAM1111089C1.
WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general public.
It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to
service or repair the product or products dealt with in this service information by anyone else could result in serious injury or death.
In order to avoid frostbite, be assured of no refrigerant leakage during the installation or repairing of refrigerant circuit.
List .....................................................................55
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1. Safety Precautions
Read the following “SAFETY PRECAUTIONS” carefully before perform any servicing.
Electrical work must be installed or serviced by a licensed electrician. Be sure to use the correct rating of the
power plug and main circuit for the model installed.
The caution items stated here must be followed because these important contents are related to safety. The
meaning of each indication used is as below. Incorrect installation or servicing due to ignoring of the instruction
will cause harm or damage, and the seriousness is classified by the following indications.
WARNING
CAUTION
The items to be followed are classified by the symbols:
This symbol denotes item that is PROHIBITED from doing.
Carry out test run to confirm that no abnormality occurs after the servicing. Then, explain to user the operation,
care and maintenance as stated in instructions. Please remind the customer to keep the operating instructions for
future reference.
1. Do not modify the machine, part, material during repairing service.
This indication shows the possibility of causing death or serious injury.
This indication shows the possibility of causing injury or damage to properties.
WARNING
2. If wiring unit is supplied as repairing part, do not repair or connect the wire even only partial wire break. Exchange the whole wiring unit.
3. Do not wrench the fasten terminal. Pull it out or insert it straightly.
4. Engage dealer or specialist for installation and servicing. If installation or servicing done by the user is defective, it will cause water
leakage, electrical shock or fire.
5. Install according to this installation instructions strictly. If installation is defective, it will cause water leakage, electric shock or fire.
6. Use the attached accessories parts and specified parts for installation and servicing. Otherwise, it will cause the set to fall, water leakage,
fire or electrical shock.
7. Install at a strong and firm location which is able to withstand the set’s weight. If the strength is not enough or installation is not properly done,
the set will drop and cause injury.
8. For electrical work, follow the local national wiring standard, regulation and the installation instruction. An independent circuit and single outlet
must be used. If electrical circuit capacity is not enough or defect found in electrical work, it will cause electrical shock or fire.
9. This equipment is strongly recommended to install with Earth Leakage Circuit Breaker (ELCB) or Residual Current Device (RCD).
Otherwise, it may cause electrical shock and fire in case equipment breakdown or insulation breakdown.
10. Do not use joint cable for indoor/outdoor connection cable. Use the specified indoor/outdoor connection cable, refer to installation
instruction CONNECT THE CABLE TO THE INDOOR UNIT and connect tightly for indoor/outdoor connection. Clamp the cable so that no
external force will be acted on the terminal. If connecting or fixing is not perfect, it will cause heat up or fire at the connection.
11. Wire routing must be properly arranged so that control board cover is fixed properly. If control board cover is not fixed perfectly, it will cause
heat-up or fire at the connection point of terminal, fire or electrical shock.
12. When install or relocate air conditioner, do not let any substance other than the specified refrigerant, eg. air etc. mix into refrigeration cycle
(piping). (Mixing of air etc. will cause abnormal high pressure in refrigeration cycle and result in explosion, injury etc.).
13. Do not install outdoor unit near handrail of veranda. When installing air-conditioner unit at veranda of high rise building, child may climb up to
outdoor unit and cross over the handrail and causing accident.
14. This equipment must be properly earthed. Earth line must not be connected to gas pipe, water pipe, earth of lightning rod and
telephone. Otherwise, it may cause electric shock in case equipment breakdown or insulation breakdown.
15. Keep away from small children, the thin film may cling to nose and mouth and prevent breathing.
16. Do not use unspecified cord, modified cord, joint cord or extension cord for power supply cord. Do not share the single outlet
with other electrical appliances. Poor contact, poor insulation or over current will cause electrical shock or fire.
17. Tighten the flare nut with torque wrench according to specified method. If the flare nut is over-tightened, after a long period, the
flare may break and cause refrigerant gas leakage.
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18. For R410A models, when connecting the piping, do not use any existing (R22) pipes and flare nuts. Using such same may
cause abnormally high pressure in the refrigeration cycle (piping), and possibly result in explosion and injury. Use only R410A
materials.
Thickness of copper pipes used with R410A must be more than 0.8mm. Never use copper pipes thinner than 0.8mm.
It is desirable that the amount of residual oil is less than 40 mg/10m.
19. During installation, install the refrigerant piping properly before run the compressor. (Operation of compressor without fixing refrigeration
piping and valves at opened condition will cause suck-in of air, abnormal high pressure in refrigeration cycle and result in explosion, injury
etc.).
20. During pump down operation, stop the compressor before remove the refrigeration piping. (Removal of refrigeration piping while
compressor is operating and valves are opened condition will cause suck-in of air, abnormal high pressure in refrigeration cycle and result
in explosion, injury etc.).
21. After completion of installation or service, confirm there is no leakage or refrigerant gas. It may generate toxic gas when the refrigerant
contacts with fire.
22. Ventilate if there is refrigerant gas leakage during operation. It may cause toxic gas when refrigerant contacts with fire.
23. Do not insert your fingers or other objects into the unit, high speed rotating fan may cause injury.
24. Must not use other parts except original parts described in catalog and manual.
25. Using of refrigerant other than the specified type may cause product damage, burst and injury etc.
CAUTION
1. Do not install the unit at place where leakage of flammable gas may occur. In case gas leaks and accumulates at surrounding of the
unit, it may cause fire.
2. Carry out drainage piping as mentioned in installation instructions. If drainage is not perfect, water may enter the room and damage
the furniture.
3. Tighten the flare nut with torque wrench according to specified method. If the flare nut is over-tightened, after a long period, the flare
may break and cause refrigerant gas leakage.
4. Do not touch outdoor unit air inlet and aluminium fin. It may cause injury.
5. Select an installation location which is easy for maintenance.
6. Pb free solder has a higher melting point than standard solder; typically the melting point is 50°F – 70°F (30°C – 40°C) higher. Please use
a high temperature solder iron. In case of the soldering iron with temperature control, please set it to 700 ± 20°F (370 ± 10°C).
Pb free solder will tend to splash when heated too high (about 1100°F / 600°C).
7. Power supply connection to the air conditioner.
Power supply cord shall be UL listed or CSA approved 4 conductor with minimum AWG12 wires.
Power supply point should be in an easily accessible place for power disconnection in case of emergency.
In some countries, permanent connection of this air conditioner to the power supply is prohibited.
Fix power supply connection to a circuit breaker for the permanent connection.
Use NRTL approved fuse or circuit breaker (rating refers to name plate) for the permanent connection.
8. Do not release refrigerant during piping work for installation, servicing, reinstallation and during repairing a refrigerant parts.
Take care of the liquid refrigerant, it may cause frostbite.
9. Installation or servicing work: It may need two people to carry out the installation or servicing work.
10. Do not install this appliance in a laundry room or other location where water may drip from the ceiling, etc.
11. Do not sit or step on the unit, you may fall down accidentally.
12. Do not touch the sharp aluminium fins or edges of metal parts.
If you are required to handle sharp parts during installation or servicing, please wear hand glove.
Sharp parts may cause injury.
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2. Specifications
2.1 CU-2E18NBK
ItemUnit OUTDOOR UNIT
Indoor Unit Combination 3.2kW + 3.2kW
Power Source
Capacity
Running Current A 7.6 - 6.9
Cooling Operation
Heating Operation
Maximum Current A 13.6
Starting Current A 9.0
Minimum Circuit Ampacity A 20
Dimension
Net Weight kg (lb) 69 (152)
Connection cable 3 + 1 (Earth) ø1.5 mm2
Pipe Length Range (1 room) m (ft) 3 ~ 25 (9.8 ~ 82.0)
Maximum Pipe Length (Total Room) m (ft) 50 (164.0)
Refrigerant Pipe Diameter
Compressor
Air Circulation
Fan Speed High RPM 570
Heat Exchanger
Electrical
Data
Noise
Capacity
Electrical
Data
Noise
Height mm (inch) 795 (31-5/16)
Width mm (inch) 875 + 95 (34-15/32 + 3-3/4)
Depth mm (inch) 320 (12-5/8)
Liquid Side mm (inch) 6.35 (1/4)
Gas Side mm (inch) 9.52 (3/8)
Type Hermetic Motor (Rotary)
Motor Type DC Brushless (4-poles)
Rated Output W 1.30k
Type Propeller Fan
Motor Type DC Brushless (8-poles)
Rated Output W 60
Type Plate fin configuration forced draft type
Tube Material Copper
Fin Material Aluminum
Row/Stage 2/36
FPI 19
Power Input kW 1.45 (0.39 ~ 1.84)
EER W/W 3.37 (5.38 ~ 3.18)
BTU/hW 11.50 (18.45 ~ 10.85)
Sound Pressure Level dB-A 48
Sound Power Level dB 62
Running Current A 9.0 - 8.1
Power Input kW 1.85 (0.42 ~ 2.29)
COP W/W 3.21 (5.02 ~ 3.14)
BTU/hW 10.90 (17.15 ~ 10.75)
Sound Pressure Level dB-A 49
Sound Power Level dB 63
kW 4.89 (2.10 ~ 5.86)
BTU/h 16700 (7200 ~ 20000)
kW 5.94 (2.11 ~ 7.20)
BTU/h 20200 (7200 ~ 24600)
1 Phase, 208 – 230V, 60Hz (Power supply from
outdoor unit)
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Item Unit OUTDOOR UNIT
Air Volume High m3/min (ft3/min) 37.2 (1313)
Refrigerant Control Device Expansion Valve
Refrigerant Oil FV50S
Refrigerant (R410A) g (oz) 1.92k (67.8)
Dry Bulb Wet Bulb
Cooling
Indoor Operation Range
Heating
Cooling
Outdoor Operation Range
Heating
Maximum °C (°F) 32 (89.6) 23 (73.4)
Minimum °C (°F) 16 (60.8) 11 (51.8)
Maximum °C (°F) 30 (86.0) —
Minimum °C (°F) 16 (60.8) —
Maximum °C (°F) 43 (109.4) 26 (78.8)
Minimum °C (°F) 16 (60.8) 11 (51.8)
Maximum °C (°F) 24 (75.2) 18 (64.4)
Minimum °C (°F) -15 (5.0) -16 (3.2)
Note
Specifications are subject to change without notice for further improvement.
Multi split combination possibility:
o A single outdoor unit enables air conditioning of up to two separate rooms for CU-2E18NBK.
Outdoor Unit
CU-2E18NBK
A B
2.8 kW CS-E9NKKW
Wall
Capacity range of connectable indoor units From 5.6 kW to 6.4 kW
1 room maximum pipe length (m (ft)) 25 (82.0)
Allowable elevation (m (ft)) 15 (49.2)
Total allowable pipe length (m (ft)) 50 (164.0)
Total pipe length for maximum chargeless length (m (ft)) 20 (65.6)
Piping Length
Additional gas amount over chargeless length (g/m (oz/ft)) 20 (0.2)
Remarks for CU-2E18NBK
1. At least two indoor units must be connected.
2. The total nominal cooling capacity of indoor untis that will be connected to outdoor unit must be within connectable capacity range of
indoor unit.
(as shown in the table above)
Example: The indoor units’ combination below is possible to connect to CU-2E18NBK. (Total nominal capacity of indoor units is between
5.6 kW to 6.4 kW)
1) Two CS-E9NKKW only. (Total nominal cooling capacity is 5.6 kW)
2) One CS-E9NKKW and one CS-E12NKKW. (Total nominal cooling capacity is 6.0 kW)
Specifications are subject to change without notice for further improvement.
3.2 kW CS-E12NKKW
Note: “
• •
• •
•” : Available
6
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Outdoor Unit
CU-2E18NBK
Indoor unit combination Cooling Capacity (kW) Input Power (W)
Specifications are subject to change without notice for further improvement.
Current (A)
208V
Current (A)
208V
Current (A)
230V
Current (A)
230V
Current (A)
208V
Current (A)
208V
Moisture
Removal
Volume
(L/h)
Moisture
Removal
Volume
(pt/h)
Current (A)
230V
Current (A)
230V
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3. Dimensions
8
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4. Refrigeration Cycle Diagram
9
Page 10
5. Block Diagram
10
Page 11
6. Wiring Connection Diagram
11
Page 12
7. Electronic Circuit Diagram
12
Page 13
8. Printed Circuit Board
8.1 Main Printed Circuit Board
13
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8.2 Noise Filter Printed Circuit Board
8.3 Display Printed Circuit Board
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9. Installation Information
9.1 Check Points
QUICK GUIDE PIPING AND ELECTRICAL SPECIFICATION
Min.
Indoor (ID) & Outdoor
(OD) units: Possible
Combination Patterns
Outdoor (OD):
CU-2E18NBK
Indoor (ID): 2 UNITS
OF CS-E9NKKW
Outdoor (OD):
CU-2E18NBK
Indoor (ID): 2 UNITS
OF CS-E12NKKW
Outdoor (OD):
CU-2E18NBK
Indoor (ID): 1 UNIT
OF CS-E9NKKW +
1 UNIT OF
CS-E12NKKW
Refrige-
rant
R410A
Piping size
Gas Liquid
Ø3/8”
(Ø9.52mm)
Ø1/4”
(Ø6.35mm)
Max.
pipe
Standard
pipe
length
7.5 m 15 m 3m 25 m 50 m20 m 20 g/m
Max.
Eleva-
tion
length
for
each
ID unit
from
OD to
each
ID
unit
Max.
total
length
Min. total
pipe
length
for
additional
gas
Addi-
tional
refrige-
rant
Power
supply
208/230V
60 Hz
MCA20A
MOP 25A
Power
supply
wire
size
AWG12 AWFG16
OD-ID
connection
wire size
Example:
If total piping length of all installed indoor units is at 22.5m, the quantity of additional refrigerant should be 50 g ......
(22.5 - 20) m x 20 g/m = 50 g
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10. Installation Instruction
10.1 Select The Best Location
10.1.1 Outdoor Unit
If an awning is built over the unit to prevent direct
sunlight or rain, be careful that heat radiation from
the condenser is not obstructed.
There should not be any animal or plant which
could be affected by hot air discharged.
Keep the spaces indicated by arrows from wall,
ceiling, fence or other obstacles.
Do not place any obstacles which may cause a
short circuit of the discharged air.
Recommended installation height for outdoor unit
should be above the seasonal snow level.
Refrigerant piping size
Outdoor Unit CU-2E18***
Liquid - side ø1/4” (ø6.35mm) t0.8mm
Gas - side ø3/8” (ø9.52mm) t0.8mm
Outdoor Unit CU-2E18***
Min. total piping length for additional gas 20m
If total piping length of all indoor units exceeds the
minimum length listed above, additionally charge
with 20g of refrigerant (R410A) for each additional
meter of piping.
Allowable piping length
Outdoor Unit CU-2E18***
Allowable piping length of each indoor unit (min. ~ max.) 3 m ~ 25 m
Allowable total piping length of all indoor unit 50 m or less
Height difference between indoor and outdoor unit
Height difference between indoor unit
Outdoor unit located on upper side
Outdoor unit located otherwise
Outdoor unit located on upper side
Outdoor unit located otherwise
15 m or less
7.5 m or less
7.5 m or less
15 m or less
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Outdoor Unit Installation Guidelines
Where a wall or other obstacle is in the path of outdoor unit’s intake or exhaust airflow, follow the installation
guidelines below.
For any of the below installation patterns, the wall height on the exhaust side should be 1200mm or less.
10.2 Install The Outdoor Unit
After selecting the best location, start installation
to Indoor/Outdoor Unit Installation Diagram.
1 Fix the unit on concrete or rigid frame firmly
and horizontally by bolt nut (ø10 mm).
2 When installing at roof, please consider strong
wind and earthquake.
Please fasten the installation stand firmly with
bolt or nails.
10.3 Connect the Piping
Remove the control board cover (resin) from the
unit by loosening three screws
Connecting The Piping To Outdoor Unit
Decide piping length and then cut by using pipe
cutter.
Remove burrs from cut edge. Make flare after
inserting the flare nut (locate at valve) onto the
copper pipe.
Align center of piping to valves and then tighten
with torque wrench to the specified torque as
stated in the table.
Model A B C D
CU-2E18*** 613 mm 131 mm 16 mm 360.5 mm
Do not over tighten, over tightening may cause gas leakage
Piping size Torque
1/4" [6.35 mm] [18 N•m (1.8 kgf.m)]
3/8" [9.52 mm] [42 N•m (4.3 kgf.m)]
1/2" [12.7 mm] [55 N•m (5.6 kgf.m)]
5/8" [15.88 mm] [65 N•m (6.6 kgf.m)]
3/4" [19.05 mm] [100 N•m (10.2 kgf.m)]
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CUTTING AND FLARING THE PIPING
1 Please cut using pipe cutter and then remove the burrs.
2 Remove the burrs by using reamer. If burrs is not removed, gas leakage may be caused.
Turn the piping end down to avoid the metal powder entering the pipe.
3 Please make flare after inserting the flare nut onto the copper pipes.
10.4 Evacuation of the Equipment
WHEN INSTALLING AN AIR CONDITIONER, BE SURE TO EVACUATE THE AIR INSIDE THE INDOOR UNIT AND
PIPES in the following procedure.
1 Connect a charging hose with a push pin to
the Low side of a charging set and the service
port of the 3-way valve.
oBe sure to connect the end of the
charging hose with the push pin to the
service port.
2 Connect the center hose of the charging set to
a vacuum pump.
3 Turn on the power switch of the vacuum pump
and make sure that the needle in the gauge
moves from 0 cmHg (0 MPa) to -76 cmHg
(-0.1 MPa). Then evacuate the air
approximately ten minutes.
4 Close the Low side valve of the charging set
and turn off the vacuum pump. Make sure that
the needle in the gauge does not move after
approximately five minutes.
Note: BE SURE TO TAKE THIS
PROCEDURE IN ORDER TO AVOID
REFRIGERENT GAS LEAKAGE.
5 Disconnect the charging hose from the
vacuum pump and from the service port of the
3-way valve.
6 Tighten the service port caps of gas side
3-way valve at a torque of 18 N•m with a
torque wrench.
7 Remove the valve caps of both of the gas side
and liquid side 3-way valve. Position both of
the valves to “OPEN” using a hexagonal
wrench (4 mm).
8 Mount valve caps onto the gas side and liquid
side of the 3-way valve.
oBe sure to check for gas leakage.
If gauge needle does not move from 0 cmHg (0 MPa) to -76 cmHg (-0.1 MPa), in step e above take the following measure:
- If the leak stops when the piping connections are tightened further, continue working from step e.
- If the leak does not stop when the connections are retightened, repair location of leak.
- Do not release refrigerant during piping work for installation and reinstallation.
- Take care of the liquid refrigerant, it may cause frostbite.
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10.5 Connect The Cable To The Outdoor Unit
1 Remove Control Board Cover (Metal) by
loosening 2 screws.
2 Remove Valve Cover (Metal) by loosening
2 screws.
3 Remove Plugs.
4 Fix the conduit connectors to the knock out
holes with lock-nuts, then secure them.
5 Connecting wire between indoor unit and
outdoor unit should be UL listed or CSA
approved 4 conductor wires minimum AWG16
in accordance with local electric codes.
6 Wire Connection to the power supply
(208/230V 60Hz) through circuit breaker.
oConnect the UL listed or CSA approved
wires minimum AWG12 to the terminal
board, and connect to other end of the
wires to circuit breaker.
7 Connect the power supply cord and
connecting wires between indoor unit and
outdoor unit according to the diagram as
shown.
8 For wire stripping and connection requirement, refer to the diagram below.
9 Secure the power supply cord and connecting cables onto the control board with the holder.
10 Attach the control board cover (metal and resin) and valve cover back to the original position with screw.
This equipment must be properly earthed.
Earth wire shall be Yellow/Green (Y/G) in colour and longer than other AC wires for safety reason.
10.6 Heat Insulation
Use a material with good heat-resistant properties as the heat insulation for the
pipes. Be sure to insulate both the gas-side and liquid-side pipes. If the pipes are
not adequately insulated, condensation or water leakages may occur.
19
Liquid-side pipes
Gas-side pipes
Material shall
withstand
120°C or higher
Page 20
11. Operation Control
11.1 Cooling Operation
11.1.1 Outdoor fan control
When cooling operation is enabled, based on outdoor ambient temperature, fan motor control will be adjusted
according to figure below:
11.1.2 Annual Cooling control
This control is to enable cooling operation when outdoor ambient temperature is low.
Control start conditions:
o Cooling operation is activated with compressor ON.
o Outdoor ambient temperature is less than 15°C
Control contents:
o When the above conditions are fulfilled, based on outdoor pipe temperature, the outdoor fan motor will
operate according to figure below:
To improve the judgment accuracy during annual cooling control, outdoor ambient temperature sampling for
2 minutes will be activated every 35 minutes under designated fan speed.
Control stop conditions:
o When either one of the start conditions are not complied.
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11.2 Heating Operation
11.2.1 Outdoor fan control
When heating operation is enabled, based on outdoor ambient temperature, fan motor control will be adjusted
according to figure below:
To improve the judgment accuracy, indoor room temperature sampling starts when any indoor unit has stopped
capability supplied (heating thermo-off) during heating operation with compressor ON, outdoor unit will send
signal to all thermo-off indoor units to ON fan motor and get room temperature sample.
To prevent discharge temperature drop at indoor units which is ON when sampling the room temperature of
heating thermo-off units, the outdoor fan speed will be adjusted accordingly.
However, if indoor room temperature is high compare to remote control setting temperature, sampling of
corresponding indoor unit will be cancelled.
11.2.2 Powerful Operation 1
During cooling operation, this control is to concentrate outdoor unit capability to the powerful operation enabled
indoor unit by temporary stop the capability supply to low load demand indoor units.
Operation start condition:
o Powerful operation ON for targeted indoor unit
Operation content:
o If other indoor units (where Powerful operation are OFF) achieve setting temperature continuously for
1 minute after received powerful command from indoor unit, then capability supply to other indoor units are
stopped for minimum 3 minutes.
Capability supply stop period follows powerful operation period.
Operation stops when comply either one of the following conditions:
o When other indoor units (where Powerful operation are OFF) is lower than setting temperature.
o When the powerful operation is OFF for all indoor units.
o When Quiet operation received from 1 indoor unit.
o When protection control starts.
11.2.3 Powerful Operation 2
During cooling / heating operation, this control is to provide fast cooling / heating operation compare to normal
operation.
Operation start if all condition below are complied:
o Powerful operation ON for indoor unit.
o Not under Annual Cooling control.
Operation content:
o Outdoor fan speed will adjust automatically.
o Compressor frequency will adjust automatically.
Operation stop when comply either one of the follow conditions:
o When the powerful operation is OFF for all indoor units.
o When annual cooling control activated.
a heating operation cannot be performed
by an indoor unit in another room.
In the room where the operation button
for cooling was pressed first, the
operation is continued. In the room where
the operation button for heating was
pressed afterward, the operation lamp of
the indoor unit blinks, where the attempt
is made to establish the heating
operation. Its fan is stopped, and the air
does not discharged.
oWhile a heating operation is in progress,
a cooling operation cannot be performed
by an indoor unit in another room.
In the room where the operation button
for heating was pressed first, the
operation is continued. In the room where
the operation button for cooling was
pressed afterward, the operation lamp of
the indoor unit blinks, where the attempt
is made to establish the cooling operation.
Its fan is stopped, and the air does not
discharged.
4 Operation mode priority control
oThe operation mode designated first by
the indoor unit has priority.
oIf the priority indoor unit stops operation
or initiates the e-ion operation, the priority
is transferred to other indoor units.
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13. Protection Control
13.1 Freeze Prevention control (Cool)
When received freeze prevention signal from indoor unit, the compressor frequency changes according to indoor
heat exchanger temperature.
When indoor unit request capability OFF due to freeze condition , immediately the capability supply to targeted
indoor unit stops.
13.2 Dew Prevention control (Cool)
When received dew prevention signal from indoor unit, the compressor frequency changes according to indoor
intake temperature and indoor heat exchanger temperature.
13.3 Electronic Parts Temperature Rise Protection 1 (Cool)
This control prevents electronic parts temperature rise during cooling overload condition.
Start conditions:
o Outdoor ambient temperature is at protection region as shown in figure below:
o Outdoor unit total current is above 5.5A
Control content
o Outdoor fan speed is adjusted accordingly.
Control stop condition
o When outdoor ambient temperature is back to normal region.
During this control, outdoor fan speed does not reduce for Quiet operation.
13.4 Electronic Parts Temperature Rise Protection 2 (Cool)
This control prevents electronic parts temperature rise during cooling/dry operation.
Start conditions:
o Total current is at protection region as shown in figure below:
Control content
o Outdoor fan speed is adjusted accordingly.
Control stop conditions
o When total current is back to normal region.
During this control, outdoor fan speed does not reduce for Quiet operation.
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13.5 Cooling overload control (Cool)
This control detect outdoor pipe temperature and perform the compressor frequency restriction during cooling
operation.
13.6 Heating overload control (Heat)
This control detect indoor pipe temperature and perform the compressor frequency restriction during heating
operation.
This control detect outdoor ambient temperature and perform the fan speed adjustment during heating operation.
13.7 Extreme Low Temperature Compressor low pressure protection control
(Heat)
This control is to prevent low pressure drops too low during extremely low outdoor ambient temperature to
improve the compressor reliability.
During heating operation, when outdoor ambient temperature is in Zone 1, this control will be activated.
Compressor frequency restriction will be based on outdoor piping temperature.
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13.8 Deice Control
When outdoor pipe temperature and outdoor air temperature is low, deice operation starts where indoor fan
motor and outdoor fan motor stop, indoor unit horizontal vane close and operation LED blink with compressor ON.
13.9 Time Delay Safety Control (Restart Control)
The compressor will not restart within three minutes after compressor is stopped.
This control is not applicable if the power supply reset or after deice condition.
13.10 30 seconds Force Operation
Once the compressor starts operation, it will not stop its operation for 30 seconds in order to cycle back
compressor oil.
However, it can be stopped using remote control or Auto OFF/ON button at indoor unit.
13.11 Total Current Control
By referring to table below, during normal (default) operation, the running current refer to Hi values and during
Power Save Mode, the running current refer to Lo values.
When the outdoor unit total running current (AC) exceeds X value, compressor frequency will decrease.
If the running current does not exceed X value for 5 seconds, compressor frequency will increase.
However, if total outdoor unit running current exceeds Y value, compressor will be stopped immediately for
3 minutes.
Operation Mode
Cooling/Soft Dry (A)
Cooling/Soft Dry (B)
Heating
X (A) Y (A)
Hi 14.0 17.5
Lo 9.8 17.5
Hi 14.0 17.5
Lo 9.8 17.5
Hi 14.0 17.5
Lo 9.8 17.5
CU-2E18NBK
13.12 IPM (power transistor) Protection Control
Overheating Prevention Control
o If IPM temperature rises to 80°C, outdoor fan speed will be increased.
o When the IPM temperature rises to 95°C, compressor operation will stop immediately.
o Compressor operation restarts when temperature decreases to 90°C.
o If IPM temperature detected less than -30°C, IPM is judged as open circuit (“F96” is indicated).
DC peak current control
o When IPM DC current exceeds set value of 30.0 ± 3.0 A, the compressor will stop.
o If the DC peak current detected within 30 seconds after operation starts, compressor will restart after
1 minute.
o If the DC peak current detected 30 seconds or more after operation starts, compressor will restart after
2 minutes.
o Within 30 seconds after compressor restarts, if the DC peak current is exceeded set value continuously for 7
times, all indoor and outdoor relays will be cut off (“F99” is indicated).
Error reset can be done by power supply reset.
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13.13 Compressor Protection Control (Gas leak detection control 1)
Control start conditions
o For 5 minutes, the compressor continuously operates and total current is low.
o During Cooling or Soft Dry operation:
Indoor intake temperature — indoor piping temperature is below 4°C.
o During Heating operation:
Indoor pipe temperature — indoor intake temperature is below 3°C.
o Not during deice control.
o Compressor ON with maximum frequency.
Control content
o Compressor stops (and restart after 3 minutes)
o If the conditions above happen 4 times within 60 minutes, the unit will stop operation (“F91” is indicated).
13.14 Compressor Protection Control (Gas leak detection control 2)
This control detect gas leakage condition to prevent compressor damage.
Control start condition
o All connected indoor units capability supply ON.
o Compressor ON with maximum frequency.
o Not during annual cooling.
o Compressor discharge temperature high.
Control content
o Compressor OFF during this control (“F91” is memorized in EEPROM)
o If the above conditions happen 2 times within 60 minutes, indoor units’ Timer LED will blinks (“F91” is
indicated at all indoor units)
13.15 Valve close detection control
This control detects 3-way valve close condition to prevent damage to refrigerant cycle.
Start conditions:
o For all connected indoor units, if Indoor intake temperature — indoor piping temperature are between -2°C
and 2°C continuously for 5 minutes after compressor ON at first cooling operation.
o The first cooling operation is defined as cooling operation is ON for less than 8 minutes after new installation
or after pump down.
Control content
o During this control, compressor stop, indoor units’ Timer LED will blink. (“F91” is indicated at indoor units)
Error reset can be done by power supply reset or reset by using remote control.
13.16 Compressor discharge high pressure protection control
This control protect by using high pressure switch during operation.
Start conditions
o High pressure switch is activated (from normally close to open) when outdoor operation mode is cooling or
heating during compressor running.
Control 1 content
o Compressor stop when high pressure switch is opened and restart after high pressure switch closed. If this
condition happen 4 times within 30 minutes, “F94” is indicated.
o After 30 minutes, counter is reset if this condition does not happen for 4 times.
Control 1 stop conditions
o Power supply reset
o Reset by using remote control
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14. Servicing Mode
14.1 CU-2E18NBK
14.1.1 Pump down operation (SW1)
Operate the pump down process according to the following procedure
o Confirm the valve on the liquid side and gas side are open.
o Press PUMP DOWN button (SW1) on the Service PCB inside the outdoor unit for more than 5 seconds.
Pump down (cooling) operation is performed for 15 minutes.
o Set the liquid side 3 way valve to close position and wait until the pressure gauge indicates 0.01Mpa
(0.1kg/cm
o Immediate set the gas side valve to close position and then press the PUMP DOWN button (SW1) to stop the
pump down operation.
NOTE: Pump down operation will stop automatically after 15 minutes if PUMP DOWN switch (SW1) is not
pressed again. Pump down operation is not started within 3 minutes after compressor is stopped.
LED 2 3 4 5 Message
Status
Pump down operation end
: Flashing
2
G).
Pump down operation in progress
3 minutes before operation end
2 minutes before operation end
1 minute before operation end
14.1.2 Test Run operation
Test operation can be carried out using TEST OPERATION button (SW2) on the Service PCB inside the outdoor
unit.
For Cooling test, press the TEST OPERATION button (SW2) for 5 seconds or more but less than 10 seconds,
LED1 and LED 2 will illuminate when shift into cooling test operation.
For Heating test, press the TEST OPERATION button (SW2) for more than 10 seconds, LED 1 and LED 3 will
illuminate when shift into heating test operation.
Press the TEST OPERATION button (SW2) again to cancel test operation.
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14.1.3 Wiring Error check
The unit capable to correct the wiring error automatically by following procedures.
o Confirm the valve on the liquid side and gas side is open.
o Press WIRING CHECK button (SW3) on the Service PCB inside the outdoor unit for more than 10 seconds
to start wiring check operation.
o Wiring check process will complete in approximately 10 minutes. However, wiring check operation will not
start within 3 minutes after compressor is stopped. When outdoor air temperature is less than 5°C or unit has
abnormality, wiring check will not start. (See NOTE 2)
The LED 2 to LED 6 in Service PCB inside the outdoor unit indicate the possibility of the correction as shown in
the table below:
LED 2 3 4 5 6 Message
Room A B - - -
All flashing Automatic correction impossible
LED2, 4, 6 and LED 3, 5
alternatively flashing
Flashing one after
Status
another
Other than above Unit has abnormality (NOTE 4)
If automatic correct is impossible, check the
indoor unit wiring and piping manually.
NOTE:
1 For two rooms connection, LED 4 and 5 are not illuminated after wiring operation complete.
2 If the outdoor air temperature is less than 5°C or unit has abnormality, wiring operation will not start.
3 After wiring check operation is complete, LED indication will illuminated until normal operation starts.
4 Follow the product diagnosis procedure.
5 When LED 1 only illuminate, indicates that outdoor unit is operating normally.
Wiring check in progress
Automatic correction completed
14.1.4 Power Save Mode
Power Save Mode can be enabled by pushing POWER SAVE switch (SW4) to ON before power supply ON.
When Power Save Mode is ON, the unit can be operate at lower running current where the breaker capacity not
achieve the requirement.
14.1.5 Mode priority function
Mode priority function can be enabled by pushing MODE PRIORITY switch (SW5) to ON before power supply
ON.
When Mode Priority Function is ON, the mode priority is given to higher capacity indoor units.
14.1.6 Cooling only function
The unit capable to limit the operation mode to Cooling Mode only (Heating mode disabled) by cutting JP1
(COOL ONLY) before power supply ON.
This function prevent wrong operation during the unit installed in server room.
This function could be disabled again by short the JP1 (COOL ONLY) before power supply ON.
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15. Troubleshooting Guide
15.1 Self Diagnosis Function
The display screen of wireless remote control unit and the self-diagnosis LEDs (green) on the outdoor printed
circuit board in the outdoor unit can be used to identify the location of the problem.
Refer to the table below to identify and solve the cause of the problem, and then re-start the air conditioner
system.
If the problem is solved and operation returns to normal.
LED 1 illuminates and others LED are off.
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16. Disassembly and Assembly Instructions
High Voltage are generated in the electrical parts area by the capacitor. Ensure that the capacitor has discharged sufficiently before proceeding
with repair work. Failure to heed this caution may result in electric shocks.
16.1 Outdoor Unit Removal Procedure
Caution! When handling electronic controller, be careful of electrostatic discharge.
16.1.1 Removing the Cabinet Top Plate and Cabinet Front Plate
1 Remove the cabinet top plate (remove the
8 screws).
2 Remove the 8 screws (1 on the center, 3 at
the top and 4 at the bottom) securing the
cabinet front plate, release the 2 hooks
(1 each at the left and right), and pull the
cabinet front plate toward front side.
WARNING
16.1.2 Remove the Control Board Cover and Particular Plates
3 Remove the control board cover (remove
3 screws).
4 Remove the particular plate (remove
2 screws).
5 Remove the particular plate (remove
2 screws).
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16.1.3 Removing the Control P.C. Board
6 Remove the drip proof cover.
7 Disconnect the connectors (lead wires of the
compressor, sensor, and others).
8 Remove the screw at the right side of the
control box, and pull out the entire control box.
9 Release the control P.C. Board tab to remove
the control P.C. Board.
16.1.4 Removing the Propeller Fan and Fan Motor
1 Follow the steps in 16.1.1 for removing the
cabinet top plate and cabinet front plate.
2 Remove the propeller fan by removing the nut
turning clockwise at its center.
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3 Disconnect the fan motor connector from the
control P.C. Board.
4 Loosen the 4 fan motor mounting screws then
remove the fan motor.
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17. Technical Data
)
)
17.1 Operation Characteristics
17.1.1 One Indoor Unit Operation
Cooling Characteristic
[Condition] Room temperature: 27°C (DBT), 19°C (WBT)
Operation condition: High fan speed
Piping Length: 7.5m
Compressor Freq: Fc
A) Indoor unit capacity: Cooling (2.8: CS-E9NKKW), service mode frequency = 28Hz