Panasonic Cu 3ks19nbucu 4ksxxnbu Technical Service Manual

							IMPORTANT
These air conditioners employ new
refrigerant R410A.
Pay special attention when
servicing the unit.
Wall mounted type
CS-MKS7NKU
CS-MKS9NKU
CS-MKS12NKU
CS-MKS18NKU
CS-MKS24NKU< Applicable Indoor Units >
TECHNICAL & SERVICE MANUAL
OUTDOOR UNIT : CU-3KS19NBU
CU-4KS24NBU
CU-4KS31NBU
DC INVERTER MULTI-SYSTEM AIR CONDITIONER
Product Code No.
1 852 361 24
1 852 361 25
1 852 361 26
REFERENCE NO. 
SM700877
Capacity at 230V
19,700 BTU/h
25,400 BTU/h
30,600 BTU/hOutdoor Model No.
CU-3KS19NBU
CU-4KS24NBU
CU-4KS31NBU
CU-3KS19NBU
CU-4KS24NBU
CU-4KS31NBU
Semi-concealed type
CS-MKS9NB4U & CZ-18BT1U
CS-MKS12NB4U & CZ-18BT1U
CS-KS18NB4UW &  CZ-18BT1U 
						

							•  Before doing repair work, please read the "     SAFETY PRECAUTIONS" carefully and fully understand them. 
•  The precautionary items here are divided into "     Warning" and "     Caution" items. 
Items in particular which may cause death or serious injury to the service personnel if the work is not performed correctly, 
are included in the "     Warning" table.
However, even precautionary items identified as "     Caution" also have the potential for serious consequences
if not performed correctly.
Important safety precautions are described for all items in both categories. Be sure to carefully follow all of them.
• Symbol Indication
:  This symbol indicates items to which we need to pay attention.
In this triangle, a definite precautionary item is described.
:  This symbol indicates the item to be prohibited.
In or close to this circle, a prohibited item is described.
:  This symbol indicates the items requiring special attention or instruction.
In or close to this circle, a prohibited item is described.
•  After doing repair work, perform a test run to confirm that there are no abnormalities.
At the same time, explain the precautions in use to the user.
SAFETY PRECAUTIONS
Warning
Before performing an overhaul, disconnect the power plug or power cable from the unit.
Performing the work with the power supplied to the unit, may cause an electric shock.
When repair work or circuit inspection that requires power supply for the air conditioner, is to be performed, 
do not touch the charging section. 
Doing so may cause an electric shock.
For the step-up capacitor attached to the electric section, perform the repair work after sufficiently discharging it.
Insufficient capacitor discharge may cause an electric shock.
Do not perform repair work on the electric sections with wet hands. 
Doing so may cause an electric shock.
Do not start or stop the air conditioner by means of connecting or disconnecting the power plug. 
Doing so may cause an electric shock or fire.
When conducting repair work only use components included in the parts list for the corresponding unit and perform 
the work with the appropriate tools.
Incorrect or poor repair work may cause an electric shock or fire.
Never modify the unit. 
Doing so may cause an electric shock or fire.
Perform all electric work according to local applicable regulations related to electrical equipment or interior wiring 
regulation and make sure to use the exclusive circuit.
Insufficient capacity to the electric circuit or defective arrangement results may cause an electric shock or fire.
Make sure to replace any power cable or lead wire showing any signs of scratch or deterioration. 
Failure to do so may cause an electric shock, overheating or fire.
Make sure that there is no dust on or slack in the power plug and insert fully into the socket. 
Dust or incomplete connections may cause an electric shock or fire.
Do not damage or process the power cord, as it may cause an electric shock or fire.                                  
For the wiring between the indoor unit and outdoor unit, securely fix the specified cable onto the terminal plate.
Poorly fixed wiring may cause a heat or fire.
After connecting the wiring between the indoor unit and outdoor unit, attach the terminal cover securely. 
Incomplete attachment of the terminal cover may cause overheating or fire.
Prohibit
Prohibit
Prohibit
Prohibit
Prohibit
2 
						

							Warning
If refrigerant gas blows off during the work, do not touch the refrigerant gas as it may cause frostbite.
If refrigerant gas leaks during the work, ventilate the room.
If refrigerant gas catches fire, harmful gas may be generated.
Do not mix any gas other than the specified refrigerant gas in the refrigerating cycle. 
If air or other contaminants mix with the gas, pressure will become extremely high in the refrigerating cycle, 
which may cause a unit breakdown."
When the welded section of the compressor intake or discharge pipe is to be disconnected, perform it in 
a well-ventilated place after sufficiently recovering the refrigerant gas.
Any residue gas may jet out refrigerant or refrigerating machine oil, which may cause an injury.
When the work is to be performed in a high place (About 2 meters or more), make sure to wear a safety helmet, 
gloves and safety belt. Insufficient safety gear may cause a serious injury in case of a fall.
When the unit is to be relocated, confirm that the new installation location has sufficient strength for the weight of the unit.
Insufficient strength of the installation location and incomplete installation work may cause an injury due to 
the unit falling.
When the remote controller batteries are replaced, dispose of the old batteries out of the reach of children. 
If a child swallows a battery, make sure that the child gets immediate medical attention.
Caution
Do not wash the air conditioner with water, as this may cause an electric shock or fire.
For the repair work in places with high humidity or moisture, make sure to ground the unit. 
Failure to do so may cause an electric shock.
Confirm that the component attachment position, wiring condition, soldering condition and connector connection 
are normal. 
If not, it may cause overheating or fire.
Confirm that the temperature around the compressor is not too high, and then perform the repair work. 
Failure to do so may cause a burn.
Perform welding work in a place with good ventilation. 
If the work is performed in a poorly ventilated area, it might cause a lack of oxygen.
If the installation plate or attachment frame has deteriorated due to corrosion, etc., replace it.
Failure to do so may cause an injury due to the unit falling.
When the cleaning is to be performed, make sure to turn off the power and pull out the plug. 
Touching the fan that is rotating at high speed may result in an injury. 
When the indoor unit is to be removed, do not place it on an incline. 
Doing so may cause wet furniture because water left inside may trickle down.
Do not hold the sharp end of the unit or the aluminum fins, as it may cause an injury to your hand or finger.
After repairs, make sure to measure the insulation resistance and confirm that the value is 1 Mohm or more. 
Any insulation error may cause an electric shock.
After repairs, make sure to check the drainage of the indoor unit. 
Inappropriate drainage may cause wet furniture and floors due to water leakage. 
Prohibit
Prohibit
Prohibit
Prohibit
Prohibit
3 
						

							Table of Contents
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     SAFETY PRECAUTIONS
TABLE OF CONTENTS
      APPLICABLE INDOOR UNITS
1.   OPERATING RANGE
2.   SPECIFICATIONS
2-1.     Unit Specifications 
2-2.     Major Component Specifications 
2-3.     Other Component Specifications 
3.   DIMENSIONAL DATA
4.   REFRIGERANT FLOW DIAGRAM
4-1.     Refrigerant Flow Diagram
5.   PERFORMANCE DATA
5-1.     Temperature Charts
5-2.     Cooling Capacity
5-3.     Cooling Capacity (Low Ambient)
6.   ELECTRICAL DATA
6-1.     Electric Wiring Diagrams
7.   FUNCTIONS
7-1.     Explanation of Functions
7-2.     Protective Functions
8.   TROUBLESHOOTING (BEFORE CALLING FOR SERVICE)
8-1.     Precautions before Performing Inspection or Repair
8-2.     Trouble Diagnosis by Error Monitop Lamps
8-3.     Checking the Outdoor System
8-4.     Trouble Diagnosis of Each Part
      8-5.     Trouble Diagnosis of Fan Motor
4 
						

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80
81
81
82
84
85
85
A-1 .........................................................................
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9.   REFRIGERANT R410A: 
SPECIAL PRECAUTIONS WHEN SERVICING UNIT
9-1.    Characteristics of New Refrigerant R410A
9-2.    Checklist before Servicing
9-3.    Tools Specifically for R410A
9-4.    Tubing Installation Procedures
9-5.    In Case of Compressor Malfunction
9-6.    In Case Refrigerant is Leaking
9-7.    Charging Additional Refrigerant
9-8.    Retro-Fitting Existing Systems
 APPENDIX A   INSTALLATION INSTRUCTIONS
5 
						

							    APPLICABLE INDOOR UNITS
CU-3KS19NBU
CU-4KS24NBU
CU-4KS31NBU Multi-Outdoor UnitIndoor Unit3-Room
4-Room
4-Room
CS-MKS7NKU
YES
YES
YESYES
YES
YESYES
YES
YESYES
YES
YESNO
YES
YES
CS-MKS9NKU CS-MKS12NKU CS-MKS18NKU CS-MKS24NKU
Wall Mounted Type
CU-3KS19NBU
CU-4KS24NBU
CU-4KS31NBU Multi-Outdoor UnitIndoor Unit3-Room
4-Room
4-Room
CS-MKS9NB4U&
CZ-18BT1U
YES
YES
YESYES
YES
YESYES
YES
YESCS-MKS12NB4U&
CZ-18BT1UCS-KS18NB4UW&
CZ-18BT1U
Semi-Concealed Type
6 
						

							95 °F DB / 71 °F WB
67 °F DB / 57 °F WB
1.  OPERATING RANGE
Maximum
Minimum115 °F DB
  14 °F DB Temperature Indoor Air Intake Temp. Outdoor Air Intake Temp.
Cooling
7 
						

							2.  SPECIFICATIONS
2-1.  Unit Specifications
Outdoor UnitCU-3KS19NBU
Indoor UnitCS-MKS9NKU × 2
< 230V >
DATA SUBJECT TO CHANGE WITHOUT NOTICE. Compressor
Refrigerant / Amount charged at shipment Ibs (g)
Refrigerant Control6.3
1,420 17,000
5.00( 6,800 to 18,800 )
( 1.90 to 5.50 )
Shipping VolumeCooling
14,300
2,700
Net
Shipping Package Dimensions
WeightHeight × Width × Depth
Height × Width × Depth
Ibs (kg)
Ibs (kg)
cu.ft (m
3) (mm)
inch
(mm)3-Room Multi Outdoor Unit
Outdoor Unit
inch187 to 253
 Dimensions & Weight
Refrigerant Tubing Connections
Unit Dimensions
Electrical Rating
Sensible Capacity
Latent Capacity
W Power InputV
A Available Voltage Range
Running Amperes
Operation Sound (High) Cool
Narrow tube
Wide tube Refrigerant inch (mm)
Tube Diameter inch (mm)
138.9
147.7
13.41 
(0.38)(63.0)
(67.0) (740 × 900 × 320)Outdoor Unit
29-1/8 × 35-7/16 × 12-19/321/4 (6.35) × 3
3/8 (9.52) × 3 ft (m)dB-A
Max. allowable tubing length per unitFlare Type
82 (25) R410A / 6.17 (2,800)
Electric Expansion Valve DC Twin Rotary (Inverter) Fan Speeds Auto (Hi, Me, Lo) ControlMicroprocessor
Features
Compressor Locked Rotor Amperes
50 BTU/h
Performance
% Power Factor98
A 13.0 Type
BTU/hkW Total Capacity
BTU/h
SEER BTU/Wh 18.0
3 Number of Connectable Indoor Units
3 Number of Operatable Indoor Units
230V Single-Phase 60Hz Voltage Rating
1,707 (2,900) Air Circulation  (High) ft3/min (m3/h)
EER BTU/h/W 12.0
Fuse or Circuit Breaker Capacity A 15
34-3/16 × 41-11/32 × 16-21/32
(868 × 1,050 × 423)
Duct Less Type Rated
Remarks:
1.  The values shown in performance section and electrical rating section above are based on the following unit combination.
  For other combination unit, please refer to the "Unit Combination Tables" in this manual.
                     Indoor Unit : CS-MKS9NKU   2units        Outdoor Unit : CU-3KS19NBU  1unit
  The combination indoor unit is AHRI 210/240.
2.  Rating conditions are:  Cooling :  Indoor air temp.  80 °F DB / 67 °F WB
      Outdoor air temp.  95 °F DB / 75 °F WB
8 
						

							Outdoor UnitCU-3KS19NBU
Indoor UnitCS-MKS9NKU ×
3
Remarks:
1.  The values shown in performance section and electrical rating section above are based on the following unit combination.
  For other combination unit, please refer to the "Unit Combination Tables" in this manual.
                     Indoor Unit : CS-MKS9NKU   3units        Outdoor Unit : CU-3KS19NBU  1unit
2.  Rating conditions are:  Cooling :  Indoor air temp.  80 °F DB / 67 °F WB
      Outdoor air temp.  95 °F DB / 75 °F WB
< 230V >
DATA SUBJECT TO CHANGE WITHOUT NOTICE. Compressor
Refrigerant / Amount charged at shipment Ibs (g)
Refrigerant Control6.7
1,500 18,800
5.50( 9,800 to 18,800 )
( 2.90 to 5.50 )
Shipping VolumeCooling
16,000
2,800
Net
Shipping Package Dimensions
WeightHeight × Width × Depth
Height × Width × Depth
Ibs (kg)
Ibs (kg)
cu.ft (m
3) (mm)
inch
(mm)3-Room Multi Outdoor Unit
Outdoor Unit
inch187 to 253
 Dimensions & Weight
Refrigerant Tubing Connections
Unit Dimensions
Electrical Rating
Sensible Capacity
Latent Capacity
W Power InputV
A Available Voltage Range
Running Amperes
Operation Sound (High) Cool
Narrow tube
Wide tube Refrigerant inch (mm)
Tube Diameter inch (mm)
138.9
147.7
13.41 
(0.38)(63.0)
(67.0) (740 × 900 × 320)Outdoor Unit
29-1/8 × 35-7/16 × 12-19/321/4 (6.35) × 3
3/8 (9.52) × 3 ft (m)dB-A
Max. allowable tubing length per unitFlare Type
82 (25) R410A / 6.17 (2,800)
Electric Expansion Valve DC Twin Rotary (Inverter) Fan Speeds Auto (Hi, Me, Lo) ControlMicroprocessor
Features
Compressor Locked Rotor Amperes
50 BTU/h
Performance
% Power Factor98
A 13.0 Type
BTU/hkW Total Capacity
BTU/h
3 Number of Connectable Indoor Units
3 Number of Operatable Indoor Units
230V Single-Phase 60Hz Voltage Rating
1,707 (2,900) Air Circulation  (High) ft3/min (m3/h)
EER BTU/h/W 12.5
Fuse or Circuit Breaker Capacity A 15
34-3/16 × 41-11/32 × 16-21/32
(868 × 1,050 × 423)
9 
						

							Outdoor UnitCU-3KS19NBU
Indoor UnitCS-MKS9NKU ×
3
< 208V >
Remarks:
1.  The values shown in performance section and electrical rating section above are based on the following unit combination.
  For other combination unit, please refer to the "Unit Combination Tables" in this manual.
                     Indoor Unit : CS-MKS9NKU   3units        Outdoor Unit : CU-3KS19NBU  1unit
2.  Rating conditions are:  Cooling :  Indoor air temp.  80 °F DB / 67 °F WB
      Outdoor air temp.  95 °F DB / 75 °F WBDATA SUBJECT TO CHANGE WITHOUT NOTICE. Compressor
Refrigerant / Amount charged at shipment Ibs (g)
Refrigerant Control7.4
1,500 18,800
5.50( 9,800 to 18,800 )
( 2.90 to 5.50 )
Shipping VolumeCooling
16,000
2,800
Net
Shipping Package Dimensions
WeightHeight × Width × Depth
Height × Width × Depth
Ibs (kg)
Ibs (kg)
cu.ft (m
3) (mm)
inch
(mm)3-Room Multi Outdoor Unit
Outdoor Unit
inch187 to 253
 Dimensions & Weight
Refrigerant Tubing Connections
Unit Dimensions
Electrical Rating
Sensible Capacity
Latent Capacity
W Power InputV
A Available Voltage Range
Running Amperes
Operation Sound (High) Cool
Narrow tube
Wide tube Refrigerant inch (mm)
Tube Diameter inch (mm)
138.9
147.7
13.41  (0.38)(63.0)
(67.0) (740 × 900 × 320)Outdoor Unit
29-1/8 × 35-7/16 × 12-19/321/4 (6.35) × 3
3/8 (9.52) × 3 ft (m)dB-A
Max. allowable tubing length per unitFlare Type
82 (25) R410A / 6.17 (2,800)
Electric Expansion Valve DC Twin Rotary (Inverter) Fan Speeds Auto (Hi, Me, Lo) ControlMicroprocessor
Features
Compressor Locked Rotor Amperes
50 BTU/h
Performance
% Power Factor98
A 13.0 Type
BTU/hkW Total Capacity
BTU/h
3 Number of Connectable Indoor Units
3 Number of Operatable Indoor Units
208V Single-Phase 60Hz Voltage Rating
1,707 (2,900) Air Circulation  (High) ft3/min (m3/h)
EER BTU/h/W 12.5
Fuse or Circuit Breaker Capacity A 15
34-3/16 × 41-11/32 × 16-21/32
(868 × 1,050 × 423)
10