Panasonic CU-2S18NBU-1 User Manual

Order No: PHAAM1111121A1

Outdoor Unit CU-2S18NBU-1

Please file and use this manual together with the service manual for Model No. CS-S9NKUW-1, CS-S12NKUW-1 Order No. PHAAM1111084C1

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 refrigerantion circuit.

PRECAUTION OF LOW TEMPERATURE

TABLE OF CONTENTS

1. Safety Precautions.............................................3

2. Specification.......................................................5

3. Dimensions.........................................................7

4. Refrigeration Cycle Diagram.............................8

5. Block Diagram....................................................9

6. Wiring Connection Diagram............................10

7. Electronic Circuit Diagram..............................11

8. Printed Circuit Board.......................................12

8.1 Main Printed Circuit Board .........................12

8.2 Noise Filter Printed Circuit Board...............13

9. Installation Information ...................................14

9.1 Check Points ..............................................14

10. Installation Instruction.....................................15

10.1 SELECT THE BEST LOCATION ...............15

10.2 INSTALL THE OUTDOOR UNIT................17

10.3 CONNECT THE PIPING............................17

10.4 EVACUATION OF THE EQUIPMENT.......18

10.5 CONNECT THE CABLE TO THE

OUTDOOR UNIT........................................18

10.6 HEAT INSULATION ...................................19

11. Operation Control.............................................20

12.12

Valve close detection control......................23

12.13 Compressor discharge high pressure

protection control ........................................23

13. Servicing Mode.................................................24

13.1 Pump Down Operation ...............................24

13.2 Test Operation............................................24

13.3 Wiring Error Check .....................................24

13.4 Power Save Mode ......................................25

13.5 Mode priority function .................................25

14. Troubleshooting Guide....................................26

14.1 Self Diagnosis Function..............................26

15. Disassembly and Assembly Instructions ......28

15.1 Outdoor Unit Removal Procedure ..............28

16. Technical Data ..................................................31

16.1 Operation Characteristics...........................31

17. Exploded View and Replacement Parts List..41

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:

• Carry out test running 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.

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.

This indication shows the possibility of causing death or serious injury.

This indication shows the possibility of causing injury or damage to properties.

This symbol denotes item that is PROHIBITED from doing.

WARNING

3. Do not wrench the fasten terminal. Pull it out or insert it straightly.

Engage authorized dealer or specialist for installation and servicing. If installation or servicing done by the user is defective, it will cause

4. 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.

Use the attached accessories parts and specified parts for installation and servicing. Otherwise, it will cause the set to fall, water leakage,

6. fire or electrical shock.

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

7. done, the set will drop and cause injury.

For electrical work, follow the local national wiring standard, regulation and the installation instruction. An independent circuit and single

8. outlet must be used. If electrical circuit capacity is not enough or defect found in electrical work, it will cause electrical shock or fire.

This equipment is strongly recommended to be installed 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.

Do not use joint cable for indoor / outdoor connection cable. Use specified indoor / outdoor connection cable, refer to Installation

10.

Instructions 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 connection or fixing is not perfect, it will cause heat up or fire at the connection.

Wire routing must be properly arranged so that control board cover is fixed properly. If control board cover is not fixed perfectly, it will

11. cause heat-up or fire at the connection point of terminal, fire or electrical shock.

When install or relocate air conditioner, do not let any substance other than the specified refrigerant, eg. air etc. mix into refrigerant cycle

12. (piping). (Mixing of air etc. will cause abnormal high pressure in refrigeration cycle and result in explosion, injury etc.).

Do not install outdoor unit near handrail of veranda. When installing air-conditioner unit at veranda of high rise building, child may

13. climb up to outdoor unit and cross over the handrail and causing accident.

This equipment must be properly earthed. Earth line must not be connected to gas pipe, water pipe, earth of lightning rod and

14. telephone. Otherwise, it may cause electrical 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.

Do not use unspecified cord, modified cord, joint cord or extension cord for power supply cord. Do not share the single outlet with

16. other electrical appliances. Poor contact, poor insulation or over current will cause electrical shock or fire.

Tighten the flare nut with torque wrench according to specified method. If the flare nut is over-tightened, after a long period, the

17. flare may break and cause refrigerant gas leakage.

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.

18.

Thickness of copper pipes used with R410A must be more than 0.8mm (1/32”). Never use copper pipes thinner than 0.8mm (1/32”). It is desirable that the amount of residual oil is less than 40 mg/10m (0.0008 oz/ft).

During installation, install the refrigerant piping properly before run the compressor. (Operation of compressor without fixing refrigeration

19.

piping and valves at opened condition will cause suck-in of air, abnormal high pressure in refrigeration cycle and result in explosion, injury etc.).

WARNING

During pump down operation, stop the compressor before remove the refrigeration piping. (Removal of refrigeration piping while

20.

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.).

After completion of installation or service, confirm there is no leakage of refrigerant gas. It may generate toxic gas when the refrigerant

21. contacts with fire.

22. Ventilate if there is refrigerant gas leakage during operation. It may cause toxic gas when the 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 describe in catalog and manual.

25. Using of refrigerant other than the specified type may cause product damage, burst and injury etc.

CAUTION

Do not install the unit at place where leakage of flammable gas may occur. In case gas leaks and accumulates at surrounding of

1. the unit, it may cause fire.

Carry out drainage piping as mentioned in installation instructions. If drainage is not perfect, water may enter the room and damage the

2. furniture.

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

3. 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.

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). Power supply connection to the air conditioner. Power supply cord shall be UL listed or CSA approved 4 conductors with minimum AWG12 wires. Power supply point should be in an easily accessible place for power disconnection in case of emergency.

7. 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.

Do not release refrigerant during piping work for installation, servicing, reinstallation and during repairing a refrigerant parts. Take

8. 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 aluminum fin, sharp parts may cause injury.

2. Specification

Model Outdoor Unit CU-2S18NBU-1

Indoor Unit Combination 3.2kW + 3.2kW

Power Source

Capacity

Running Current A 7.6 - 6.9

Cooling Operation

Maximum Current A 13.6

Starting Current A 7.8

Minimum Circuit Ampacity A 20

Dimension

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 650

Heat Exchanger

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)

Indoor Operation Range Cooling

Outdoor Operation Range Cooling

Electrical

Data

Noise

Net Weight kg (Ib) 69 (152)

Rated Output W 1.30k

Rated Output W 60

Tube Material Copper

Dry Bulb Wet Bulb

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

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 (Rotary)

Motor Type DC Brushless (4-poles)

Type Propeller Fan

Motor Type DC Brushless (8-poles)

Type Plate fin configuration forced draft type

Fin Material Aluminum

Row/Stage 2/36

FPI 19

Maximum °F 89.6 73.4

Minimum °F 60.8 51.8

Maximum °F 109.4 78.8

Minimum °F 60.8 51.8

kW 4.89 (2.10 ~ 5.86)

BTU/h 16700 (7200 ~ 20000)

Note

• Specifications are subject to change without notice for further improvement.

1 Phase, 208-230V, 60Hz

(Power supply from outdoor unit)

• Multi split combination possibility:

o A single outdoor unit enables air conditioning of up to two separate rooms for CU-2S18NBU-1.

Outdoor Unit CU-2S18NBU-1 A B

2.8 kW CS-S9NKUW-1 ● ●

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-2S18NBU-1

1. At least two indoor units must be connected.

2. The total nominal cooling capacity of indoor unit 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-2S18NBU-1. (Total nominal capacity of indoor units is between 5.6 kW to 6.4 kW)

1) Two CS-S9NKUW-1 only. (Total nominal cooling capacity is 5.6 kW)

2) One CS-S9NKUW-1 and one CS-S12NKUW-1. (Total nominal cooling capacity is 6.0 kW)

3.2 kW CS-S12NKUW-1 ● ●

Note: “●” : Available

Outdoor Unit

CU-2S18NBU-1

Indoor unit combination Capacity (kW) Input Power (W)

Operation Class (kW)

One-room Operation

Two-room Operation

2.8 2.82 1.81 ~ 3.27 850 390 ~ 1020 4.5 4.1 0.5

3.2

2.8 + 2.8 4.89 2.09 ~ 5.86 1450 390 ~ 1920 7.6 6.9 0.5 + 0.5

2.8 + 3.2 4.89 2.10 ~ 5.86 1450 390 ~ 1870 7.6 6.9 0.5 + 0.6

3.2 + 3.2

Operation

Mode

Cooling

Rating Min - Max Rating Min - Max

3.21 1.85 ~ 3.75 1000 390 ~ 1230 5.2 4.7 0.6

4.89 2.10 ~ 5.86 1450 390 ~ 1840 7.6 6.9 0.6 + 0.6

Current (A)

208V 60Hz

Current (A)

230V 60Hz

Moisture Removal

Volume (L/h)

Outdoor Unit

CU-2S18NBU-1

Indoor unit combination Capacity (BTU/h) Input Power (W)

Operation Class (kW)

One-room Operation

Two-room Operation

2.8 9600 6200 ~ 11200 850 390 ~ 1020 4.5 4.1 1.1

3.2

2.8 + 2.8 16700 7100 ~ 20000 1450 390 ~ 1920 7.6 6.9 1.1 + 1.1

2.8 + 3.2 16700 7200 ~ 20000 1450 390 ~ 1870 7.6 6.9 1.1 + 1.3

3.2 + 3.2

Operation

Mode

Cooling

Rating Min - Max Rating Min - Max

10900 6300 ~ 12800 1000 390 ~ 1230 5.2 4.7 1.3

16700 7200 ~ 20000 1450 390 ~ 1840 7.6 6.9 1.3 + 1.3

Current (A)

208V 60Hz

Current (A)

230V 60Hz

Moisture Removal

Volume (Pt/h)

• Specifications are subject to change without notice for further improvement.

3. Dimensions

4. Refrigeration Cycle Diagram

5. Block Diagram

6. Wiring Connection Diagram

7. Electronic Circuit Diagram

8. Printed Circuit Board

8.1 Main Printed Circuit Board

8.2 Noise Filter Printed Circuit Board

9. Installation Information

9.1 Check Points

QUICK GUIDE

PIPING & ELECTRICAL SPECIFICATION

Indoor(ID) & Outdoor(OD) units:

Possible Combination Patterns

Outdoor (OD): CU-2S18NBU-1

Indoor (ID): 2 UNITS OF

CS-S9NKUW-1

Outdoor (OD): CU-2S18NBU-1

Indoor (ID): 2 UNITS OF

CS-S12NKUW-1

Outdoor (OD): CU-2S18NBU-1

Indoor (ID): 1 UNIT OF

CS-S9NKUW-1

+ 1 UNIT OF CS-S12NKUW-1

Capacity

Refrigerant

(Btu/h)

16700 R410A

Piping size

Gas Liquid

ø3/8"

(ø9.52mm)

ø1/4"

(ø6.35mm)

Standard

pipe

length

24.6 ft 49.2 ft 9.8 ft 82.0 ft 164.0 ft 65.6 ft 0.2 oz / ft

Max.

Elevation

Min. pipe length for

each ID

unit

Max. from

OD to

each ID

Max.

total

length

Min. total

pipe

length for

additional

gas

Additional refrigerant

Power supply

208/230V

60 Hz MCA 20A MOP 25A

Power

OD-ID

supply

connection

wire size

AWG12 AW G16

Example:

If total piping length of all installed indoor units is at 68.6 ft, the quantity of additional refrigerant should be 0.6 oz .......... (68.6 – 65.6) ft x 0.2 oz/ ft

= 0.6 oz.

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-2S18***

Liquid - side ø1/4" thickness 1/32"

Gas - side ø3/8" thickness 1/32"

Outdoor Unit CU-2S18***

Min. total piping length for

additional gas

• If total piping length of all indoor units exceeds the minimum length listed above, additionally charge with 0.2 oz of refrigerant (R410A) for each additional feet of piping.

Allowable piping length of each indoor unit (min. ~ max.) 9.8 ft ~ 82.0 ft

Allowable total piping length of all indoor unit 164.0 ft or less

Height difference between indoor and outdoor unit

Height difference between indoor unit

65.6 ft

Allowable piping length

Outdoor Unit CU-2S18***

Outdoor unit located on upper side

Outdoor unit located otherwise

Outdoor unit located on upper side

Outdoor unit located otherwise

10.1.2 Outdoor Unit Installation Diagram

• This illustration is for explanation purposes only.

* Note: Respective indoor unit installation procedure shall

refer to instruction manual provided in the indoor unit packaging.

49.2 ft or less

24.6 ft or less

49.2 ft or less

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 47 1/4" 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 with bolt nut (ø13/32").

2. When installing on a roof, please consider strong winds and earthquakes. Please fasten the installation stand firmly with bolt or nails.

Model A B C D

CU-2S18*** 24-1/8" 5-5/32" 5/8" 14-3/16"

10.3 CONNECT THE PIPING

• Remove the control board cover (resin) from the outdoor unit by loosening three screws.

10.3.1 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.

Do not overtighten, over tightening may cause gas leakage.

Piping size Torque

1/4" (0.02 ft) [18 N•m (13.3 Ibf. ft)]

3/8" (0.03 ft) [42 N•m (31.0 Ibf. ft)]

1/2" (0.04 ft) [55 N•m (40.6 Ibf. ft)]

5/8" (0.05 ft) [65 N•m (47.9 Ibf. ft)]

3/4" (0.06 ft) [100 N•m (73.8 Ibf. ft)]

10.3.2 Gas Leak Checking

Pressure test to system to 400 PSIG with dry nitrogen, in stages. Thoroughly leak check the system. If the pressure holds, release the nitrogen and proceed to section 10.4.

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 gas side 3-way valve.

2. Connect the micron gauge between vacuum pump and service port of outdoor units.

3. Turn on the power switch of the vacuum pump and make sure that connect digital micron gauge and to pull down to a value of 500 microns.

4. To make sure micron gauge a value 500 microns and close the low side valve of the charging set and turn off the vacuum pump.

5. Disconnect the vacuum pump house 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 13.3 Ibf.ft with a torque wrench.

7. Remove the valve caps of both of the 2-way valve and 3-way valve. Position both of the valves to “Open” using a hexagonal wrench (5/32").

8. Mount valve caps onto the 2-way valve and 3way valve.

• Be sure to check for gas leakage.

CAUTION

• If micron gauge value does not descend 500 microns, take the following measures:

o If the leak stops when the piping connections are tightened further, continue working from step e. o If the leak does not stop when the connections are retightened, repair location of leak. o Do not release refrigerant during piping work for installation and reinstallation. o Take care when handling the liquid refrigerant, it may cause frostbite.

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.

• Connect 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.

10.6 HEAT INSULATION

se a material with good heat-resistant properties as the heat insulation for

Liquid-side pipes

CAUTION

he 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.

Gas-side pipes

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.

Material shall

withstand 248°F or

higher

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 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

minutes 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.

11.1.3 Powerful Operation 2

• During cooling operation, this control is to provide fast cooling operation compare to normal operation.

• Operation start if all condition below are complied:

o Powerful operation ON for indoor unit.

• 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.

12. Protection Control

12.1 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.

12.2 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.

12.3 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.

12.4 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 condition

o When total current is back to normal region.

• During this control, outdoor fan speed does not reduce for Quiet operation.

12.5 Cooling overload control (Cool)

• This control detect outdoor pipe temperature and perform the compressor frequency restriction during cooling operation.

12.6 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.

12.7 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.

12.8 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)

Hi 14.0 17.5

Lo 7.8 17.5

Hi 14.0 17.5

Lo 7.8 17.5

X (A) Y (A)

CU-2S18NBU-1

12.9 IPM (power transistor) Protection Control

• Overheating Prevention Control

o If IPM temperature rises to 176°F, outdoor fan speed will be increased. o When the IPM temperature rises to 203°F, compressor operation will stop immediately. o Compressor operation restarts when temperature decreases to 194°F. o If IPM temperature detected less than -22°F, 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

minute.

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.

12.10 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 39.2°F.

• 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).

12.11 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 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)

12.12 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 28.4°F

and 35.6°F 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.

12.13 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

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

13. Servicing Mode

13.1 Pump Down Operation

• Operate the pump down according to the following procedures. 1 Confirm the valve on the liquid side and gas

side is open.

2 Press PUMP DOWN switch (SW1) on the

display printed circuit board for more than 5 seconds. Pump down (cooling) operation is performed for 15 minutes.

3 Set the liquid side 3 way valve to close

position and wait until the pressure gauge indicates 1.45 PSI.

4 Immediately set the gas side valve to close

position and then press the PUMP DOWN switch (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 cannot be restarted until 3 minutes after compressor is stopped.

LED 2 3 4 5 Message

○ ○ ○ ○ ○ ○ ○ ○ ○

Status

○

2 minutes before operation end

1 minute before operation end

Pump down operation end

Pump down operation progress

3 minutes before operation end

○ : Flashing

13.2 Test Operation

• Test operation can be carried out using OPERATION TEST switch (SW2) on the display printed circuit board inside the outdoor unit. For cooling test, press the TEST OPERATION switch (SW2) for more than 5 seconds. LED 1 and LED 2 will illuminate when shift into cooling test operation.

13.3 Wiring Error Check

This product capable to correcting the wiring errors automatically by following procedures.

1 Confirm the valve on the liquid side and gas

side is open.

2 Press WIRING CHECK switch (SW3) on the

display printed circuit board for more than 10 seconds to start wiring check operation.

3 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 41°F or unit has abnormality, wiring check will not start. (See

NOTE 2). The LED 2 to 6 in display printed circuit board inside the outdoor unit indicate whether correction is possible or not and the status of the correction, as shown in the table below.

LED 2 3 4 5 6 Message

ROOM A B - - -

All flashing Automatic correction impossible

LED 2, 4, 6 and LED 3,

5 alternatively flashing

Flashing one after

Status

another

Other than above Unit has abnormally (Note 4)

If automatic correct is impossible, check the indoor unit wiring and piping manually.

Wiring check in progress

Automatic correction completed

NOTE

1. For two rooms, LED 4 and 5 are not illuminated after wiring operation complete.

2. If the outdoor air temperature is less than 41°F 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. (Check the diagnostic label at the control board cover.)

5. When LED 1 only illuminate, indicates that outdoor unit is operating normally.

13.4 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.

13.5 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. Troubleshooting Guide

14.1 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.

Diagnosis

display

H11

H12

H15

H16

H27

H28

H32

H33

H36

H37

H64

H97

Abnormality

Protection

control

Indoor/outdoor

abnormal

communication

Indoor unit

capacity

unmatched

Compressor temperature

sensor

abnormality

Outdoor

current

transformer

(CT)

abnormality

Outdoor air

temperature

sensor

abnormality

Outdoor heat

exchanger

temperature

sensor 1

abnormality

Outdoor heat

exchanger

temperature

sensor 2

abnormality

Indoor/outdoor misconnection

abnormality

Outdoor gas

pipe

temperature

sensor

abnormality

Outdoor liquid

pipe

temperature

sensor

abnormality

Outdoor high

pressure

sensor

abnormality

Outdoor fan

motor

mechanism

lock

LED 6 LED 5 LED 4 LED 3 LED 2 LED 1 Abnormality

○

○ ○

○

○ ○

○

○ ○

○ ○ ○

○

○ ○

operation for

○

power supply

○

for 1 minutes

happen within

○

Judgment

After

1 minute

90s after

Continuous

for 5s

― ―

Continuous

for 5s

Continuous

for 5s

Continuous

for 5s

― ―

Continuous

for 5s

Continuous

for 5s

Continuous

2 times

30 minutes

Protection

Operation

Indoor fan only

operation can

start by entering into force cooling

operation

―

Heating

protection

operation only

Cooling

protection

operation only

―

Problem Check location

• Indoor/outdoor

Indoor/outdoor

communication

not establish

Total indoor

capability more

than maximum

limit or less than

minimum limit, or

number of

indoor unit less

than two

Compressor

temperature

sensor open or

short circuit

Current

transformer

faulty or

compressor

faulty

Outdoor air

temperature

sensor open or

short circuit

Outdoor heat

exchanger

temperature

sensor 1 open or

short circuit

Outdoor heat

exchanger

temperature

sensor 2 open or

short circuit

Indoor and

outdoor rated

voltage different

Outdoor gas pipe

temperature

sensor open or

short circuit

Outdoor liquid

pipe temperature

sensor open or

short circuit

High pressure

sensor open

circuit during

compressor stop

Outdoor fan motor

lock or feedback

abnormal

wire terminal

• Indoor/outdoor PCB

• Indoor/outdoor connection wire

• Indoor/outdoor PCB

• Specification and combination table in catalogue

• Compressor temperature sensor lead wire and connector

• Outdoor PCB faulty or compressor faulty

• Outdoor air temperature sensor lead wire and connector

• Outdoor heat exchanger temperature sensor 1 lead wire and connector

• Outdoor heat exchanger temperature sensor 2 lead wire and connector

• Indoor and outdoor units check

• Outdoor gas pipe temperature sensor lead wire and connector

• Outdoor liquid pipe temperature sensor lead wire and connector

• High pressure sensor

• Lead wire and connector

• Outdoor fan motor lead wire and connector

• Fan motor lock or block

Diagnosis

display

H98

H99

F11

F17

F90

F91

F93

F94

F95

F96

F97

F98

F99

Abnormality

Protection

control

Indoor high

pressure

protection

Indoor

operating unit

freeze

protection

4-way valve

switching

abnormality

Indoor standby

units freezing

abnormality

Power factor

correction

(PFC) circuit

protection

Refrigeration

cycle

abnormality

Compressor

abnormal

revolution

Compressor

discharge

pressure overshoot protection

Outdoor cooling

high pressure

protection

Power transistor

module

overheating

protection

Compressor

overheating

protection

Total running

current

protection

Outdoor direct

current (DC)

peak detection

LED 6 LED 5 LED 4 LED 3 LED 2 LED 1 Abnormality

○ ○ ○

○ ○ ○ ○

○

○ ○

○

○ ○

○ ○ ○

○

○ ○

Judgment

― ―

4 times

happen within

30 minutes

3 times

happen within

40 minutes

4 times

happen within

○

10 minutes

2 times

happen within

20 minutes

4 times

happen within

20 minutes

4 times

happen within

30 minutes

4 times

happen within

○

20 minutes

4 times

happen within

30 minutes

3 times

happen within

30 minutes

3 times

happen within

20 minutes

Continuous

happen for 7

○

times

Protection

Operation

―

Problem Check location

Indoor high

pressure

protection

(Heating)

Indoor freeze

protection

(Cooling)

4-way valve

Switching

abnormal

Wrong wiring and

connecting pipe, expansion valve

leakage, indoor heat exchanger

sensor open circuit

Power factor

correction circuit

abnormal

Refrigeration

cycle abnormal

Compressor

abnormal

revolution

Compressor

discharge pressure

overshoot

Cooling high

pressure

protection

Power transistor module overheat

Compressor

overheat

Total current

protection

Power transistor

module current

protection

• Check indoor heat exchanger

• Air filter dirty

• Air circulation

short circuit

• Check indoor heat exchanger

• Air filter dirty

• Air circulation

short circuit

• 4-way valve

• Lead wire and

connector

• Check indoor/ outdoor connection wire and pipe

• Indoor heat exchanger sensor lead wire and connector

• Expansion valve lead wire and connector

• Outdoor PCB faulty

• Insufficient refrigerant or valve close

• Power transistor module faulty or

compressor lock

• Check refrigeration system

• Outdoor air circuit

• PCB faulty

• Outdoor air circuit

(fan motor)

• Insufficient refrigerant

• Check refrigeration system

• Power source or compressor lock

• Power transistor module faulty or

compressor lock

LED 1 illuminate is indicated that outdoor unit is operating normally. If the LED 1 is switched off or flashing, check the power supply and self-diagnosis indication.

---------- Illuminate

●

---------- Flashing

○

Blank

---------- OFF

15. Disassembly and Assembly Instructions

High Voltages 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.

15.1 Outdoor Unit Removal Procedure

Caution! When handling electronic controller, be careful of electrostatic discharge.

15.1.1 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

15.1.2 Remove the Control Board Cover and Particular Plates

3. Remove the control board cover (remove 3 screw).

4. Remove the particular plate (remove 2 screw).

5. Remove the particular plate (remove 2 screw).

15.1.3 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.

15.1.4 Removing the Propeller Fan and Fan Motor

1. Follow the steps in 15.1.1 for removing the cabinet top plate and cabinet front plate.

2. Remove the propeller fan by removing the nut turning clockwise at its center.

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.

16. Technical Data

16.1 Operation Characteristics

16.1.1 CS-S9NKUW-1 CU-2S18NBU-1

• Cooling Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Piping length: 24.6ft o Compressor Freq: Fc

• Piping Length Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Outdoor temperature: 95°F (DBT) o Compressor Freq: Fc

16.1.2 CS-S9NKUW-1x2 CU-2S18NBU-1

• Cooling Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Piping length: 24.6ft o Compressor Freq: Fc

• Piping Length Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Outdoor temperature: 95°F (DBT) o Compressor Freq: Fc

16.1.3 CS-S12NKUW-1 CU-2S18NBU-1

• Cooling Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Piping length: 24.6ft o Compressor Freq: Fc

• Piping Length Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Outdoor temperature: 95°F (DBT) o Compressor Freq: Fc

16.1.4 CS-S12NKUW-1x2 CU-2S18NBU-1

• Cooling Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Piping length: 24.6ft o Compressor Freq: Fc

• Piping Length Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Outdoor temperature: 95°F (DBT) o Compressor Freq: Fc

16.1.5 CS-S12NKUW-1+CS-S9NKUW-1 CU-2S18NBU-1

• Cooling Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Piping length: 24.6ft o Compressor Freq: Fc

• Piping Length Characteristic

o Room temperature: 81°F (DBT), 66°F (WBT) o Operation condition: High fan speed o Outdoor temperature: 95°F (DBT) o Compressor Freq: Fc

17. Exploded View and Replacement Parts List

Note The above exploded view is for the purpose of parts disassembly and replacement. The non-numbered parts are not kept as standard service parts.

REF. NO. DESCRIPTION & NAME QTY. CU-2S18NBU-1 REMARK

1 BASE PAN ASS'Y 1 CWD52K1240A 2 SOUND-PROOF BOARD 1 CWH151230 3 FAN MOTOR BRACKET 1 CWD541127 5 CONDENSER COMPLETE 1 CWB32C2925 6 FAN MOTOR 1 EHDS80CAC O 8 PROPELLER FAN 1 CWH00K1006

9 NUT - PROPELLER FAN 1 CWH561038J 10 COMPRESSOR 1 5KD184XAB21 11 PACKING 3 CWB81043 12 ANTI - VIBRATION BUSHING 3 CWH50055 13 NUT - COMPRESSOR 3 CWH561049 16 ACUMULATOR 1 CWB131050 17 3-WAY VALVE (LIQUID) 2 CWB011601 O 18 3-WAY VALVE(GAS) 2 CWB011602 O 19 HOLDER COUPLING 1 CWH351170 20 STRAINER 1 CWB111062 21 STRAINER 2 CWB111063 22 EXPANSION VALVE 2 CWB051029 23 4-WAYS VALVE 1 CWB001057 24 DISCHARGE MUFFLER 1 CWB121042 25 PRESSURE SWITCH 1 CWA101007 26 UNION NUT 4 CWT251030 27 UNION NUT 4 CWT251031 28 SOUND PROOF MATERIAL 1 CWG302246 29 SOUND PROOF MATERIAL 1 CWG302520 30 SOUND PROOF MATERIAL 1 CWG302521 31 SOUND PROOF MATERIAL 1 CWG302522 32 SENSOR-COMPLETE 1 CWA50C2722 O 34 V-COIL COMPLETE 1 CWA43C2381 O 35 V-COIL COMPLETE 1 CWA43C2382 O 39 SENSOR-COMPLETE 1 CWA50C2710 O 40 SENSOR-COMPLETE 1 CWA50C2691 O 42 HOLDER-SENSOR 1 CWH32074 43 ELECTRONIC CONTROLLER-MAIN 1 CWA73C6132R O 44 ELECTRONIC CONT.-NOISE FILTER 1 CWA745975 O 47 REACTOR 1 G0C403J00001 O 48 TERMINAL BOARD ASS'Y 1 CWA28K1195 O 49 TERMINAL BOARD ASS'Y 2 CWA28K1196 O 50 CONTROL BOARD COVER(TOP) 1 CWH131333 52 CABINET TOP PLATE 1 CWE031131A 53 CONTROL BOARD COVER COMPLETE 1 CWH13C1209 54 CABINET FRONT PLATE CO. 1 CWE06K1071 55 CABINET SIDE PLATE( L ) 1 CWE041489A 56 CABINET SIDE PLATE( R ) 1 CWE041499A 57 WIRE NET 1 CWD041128A 58 HANDLE 1 CWE161010 60 INSTALLATION INSTRUCTION 1 CWF615180 61 MANIFOLD TUBE ASS'Y(GAS) 1 CWT07K1522 62 TUBE ASS'Y (LIQUID 1) 1 CWT026316 63 TUBE ASS'Y (LIQUID 2) 1 CWT026872 64 CONTROL BOARD COVER 1 CWH131364 65 CLIP FOR SENSOR HOLDER 3 CWH711010 66 BAG 1 CWG861154 67 BASE BOARD-COMPLETE 1 CWG62C1081 68 SHOCK ABSORBER (RIGHT) 1 CWG712879

REF. NO. DESCRIPTION & NAME QTY. CU-2S18NBU-1 REMARK

69 SHOCK ABSORBER (LEFT) 1 CWG712880 70 C.C.CASE 1 CWG565609 76 TERMINAL COVER 1 CWH171035 77 NUT - TERMINAL COVER 2 CWH7080300J

(Note)

• All parts are supplied from PHAAM, Malaysia (Vendor Code: 00029488).

• “O” marked parts are recommended to be kept in stock.

Printed in Malaysia

SB1111-0

Panasonic CU-2S18NBU-1 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual