Panasonic Cu 3ke19nbucu Technical Service Manual

							9-5.  In Case of Compressor Malfunction 
CAUTIONShould the compressor malfunction, be sure to make the switch to a replacement 
compressor as quickly as possible.
Use only the tools indicated exclusively for R410A.     See "9-3. Tools Specifically 
for R410A."
9-5-1.  Procedure for Replacing Compressor
(1) Recovering refrigerant
Any remaining refrigerant inside the unit should not be 
released to the atmosphere, but recovered using the 
refrigerant recovery unit for R410A. 
Do not reuse the recovered refrigerant, since it will contain 
impurities. 
(2) Replacing Compressor
Soon after removing seals of both discharge and suction 
tubes of the new compressor, replace it quickly.
(3) Checking for sealing
Use nitrogen gas for the pressurized gas, and never use a 
refrigerant other than R410A. Also do not use oxygen or 
any flammable gas.
(4) Evacuation
Use a solenoid valve-installed vacuum pump so that 
even if power is cut off in the middle of evacuation of air 
due to a power interruption, the valve will prevent the 
pump oil from flowing back.
The equipment may be damaged if moisture remains in 
the tubing, thus carry out the evacuation thoroughly.
When using a vacuum pump with exhaust air volume more 
than 0.883 cu.ft./min. and ultimate vacuum pressure rate 
of 50 micron Hg.
Standard time for evacuation
(1) Recover refrigerant
OK
(2) Replace compressor
OK
(3) Check for sealing
OK
(4) Evacuation
OK
(5) Recharge
Length of tubing
Evacuation timeLess than 33 ft. (10 m)
More than 10 minutesMore than 33 ft. (10 m)
More than 15 minutes
91 
						

							Valve
Single valve
Charge liquid refrigerant with 
cylinder in up-side-down position.
Single valve (with siphon tube)
Charge with cylinder in normal position.Liquid
Valve
Liquid
Charging
cylinder
Open
Refrigerant
cylinder
Liquid
NO!
CAUTIONNever charge a large amount 
of liquid refrigerant at once to 
the unit. This may cause 
damage to the compressor.
CAUTIONTo prevent the composition 
of R410A from changing, 
never bleed the refrigerant 
gas into the atmosphere 
while transferring the 
refrigerant. (Fig. 3) (5) Recharging
Be sure to charge the specified amount of 
refrigerant in liquid state using the service port 
of the wide tube service valve. The proper 
amount is listed on the unit's nameplate. 
When the entire amount cannot be charged all at 
once, charge gradually while operating the unit in 
Cooling Operation.
When charging with a refrigerant cylinder, use an 
electronic scale for charging refrigerant. In this 
case, if the volume of refrigerant in the cylinder 
becomes less than 20% of the fully-charged 
amount, the composition of the refrigerant starts 
to change. Thus, do not use the refrigerant if 
the amount in the charging cylinder is less 
than 20%.
Also, charge the minimum necessary amount to 
the charging cylinder before using it to charge 
the air conditioning unit.
Example:
In case of charging refrigerant to a unit requiring 
1.68 lb. (0.76 Kg) using a capacity of a 22 lb. (10 
Kg) cylinder, the minimum necessary amount for 
the cylinder is: 
1.68 + 22    0.20 = 6.08 lb.
(0.76 + 10    0.20 = 2.76 Kg)
For the remaining refrigerant, refer to the 
instructions of the refrigerant manufacturer.
If using a charging cylinder, transfer the specified 
amount of liquid refrigerant from the refrigerant 
cylinder to the charging cylinder. 
Prepare an evacuated charging cylinder 
beforehand.
Do not use the refrigerant if the amount in the 
charging cylinder is less than 20%.
Configuration and characteristics of cylinders
Fig. 1
Fig. 2
Fig. 3
92 
						

							Length of tubing
Evacuation timeLess than 33 ft. (10 m)
More than 10 minutesMore than  33 ft. (10 m)
More than 15 minutes
9-6.  In Case Refrigerant is Leaking
CAUTIONNever attempt to charge additional refrigerant when refrigerant has been leaking 
from the unit. Follow the procedure described below to locate points of leaks and 
carry out repairs, then recharge the refrigerant.
(1) Detecting Leaks
Use the detector for R410A to locate refrigerant leak 
points. 
(2) Recovering refrigerant
Never release the gas to the atmosphere; recover 
residual refrigerant using the refrigerant recovery unit for 
R410A, instead.
Do not reuse the recovered refrigerant because its 
composition will have been altered.
(3) Welding leaking points
Confirm again that no residual refrigerant exists in the unit 
before starting welding.
Weld securely using flux and wax for R410A.
Prevent oxide film from forming inside the tubes utilizing 
substitution with nitrogen (N2) in the refrigerant circuit of 
the unit. Leave ends of tubes open during welding.
(4) Checking for sealing
Use nitrogen gas for the pressurized gas, and never use 
a refrigerant other than R410A. Also do not use oxygen or 
any flammable gas.
(5) Evacuation
Use a solenoid valve-installed vacuum pump so that 
even if power is cut off in the middle of evacuation of air 
due to a power interruption, the valve will prevent the 
pump oil from flowing back.
The equipment may be damaged if moisture remains in 
the tubing, thus carry out the evacuation thoroughly.
When using a vacuum pump with exhaust air volume 
more than 0.883 cu.ft./min. and ultimate vacuum pressure 
rate of 50 micron Hg.
Standard time for evacuation
(6) Recharging
Recharge unit in the same manner explained on the 
previous page "(5) Recharging."
(2) Recover refrigerant
OK
(3) Weld leaking points
OK
(4) Check for sealing
OK
(5) Evacuation
OK
(6) Recharge
(1) Detect leaks
OK
93 
						

							9-7.  Charging Additional Refrigerant
9-7-1.  When Tubes are Extended
Observe the proper amount of refrigerant as stated in this service manual or the installation manual that came 
with the indoor unit. Charge additional refrigerant in liquid state only. 
9-8.  Retro-Fitting Existing Systems
9-8-1.  Use of Existing Units
Never use new refrigerant R410A for existing units which use R22. This will cause the air conditioner to 
operate improperly and may result in a hazardous condition.
9-8-2.  Use of Existing Tubing
If replacing an older unit that used refrigerant R22 with a R410A unit, do not use its existing tubing. Instead, 
completely new tubing must be used.
CAUTIONNever charge additional refrigerant if refrigerant is leaking from the unit. Follow 
instructions given in "9-6. In Case Refrigerant is Leaking" and completely carry out 
repairs. Only then should you recharge the refrigerant.
94 
						

							INSTALLATION INSTRUCTIONS
CU-3KE19NBU
CU-4KE24NBU
CU-4KE31NBU
(852-6-4190-584-00-2)
APPENDIX A
A-1 
						

							For Outdoor Unit
This air conditioner uses the refrigerant R410A. 
External diameter of service port R410A: 5/16" 
Split System Air Conditioner 
85264190584002 2011 CV6233187853
INSTALLATION INSTRUCTIONS 
NOTE
Contents
Page
IMPORTANT!
Please Read Before Starting..................................2
1. GENERAL..........................................................4
1-1. Tools Required for Installation (not supplied)
1-2. Accessories Supplied with Unit
1-3. Optional Copper Tubing Kit
1-4. Type of Copper Tube and Insulation Material
1-5. Additional Materials Required for Installation
2. INSTALLATION SITE SELECTION...................5
2-1. Indoor Unit
2-2. Connecting Indoor Units
2-3. Outdoor Unit
2-4. Baffle Plate for the Outdoor Unit
2-5. Outer Dimensions of Outdoor Unit
2-6. Diagram of Outdoor Unit Installation
3. INSTALLATION PROCESS..............................16
3-1. Embedding the Tubing and Wiring
3-2. Use of the Flaring Method
3-3. Flaring Procedure with a Flare Tool
3-4. Caution before Connecting Tubes Tightly
3-5. Tubing Connections
3-6. Insulation of Refrigerant Tubing
3-7. Taping the Tubes
3-8. Finishing the Installation
4. AIR PURGING...................................................19
Air Purging with a Vacuum Pump (for Test Run)
Pump Down
5. WIRING INSTRUCTIONS................................22
5-1. General Precautions on Wiring
5-2. Recommended Wire Length and Diameter
5-3. Wiring System Diagram
5-4. How to Connect Wiring to the Terminal
5-5. Wiring Instructions for the Outdoor Unit
6. TEST RUN.........................................................26
7. CONNECTING A HOME AUTOMATION
DEVICE.............................................................27
8. INSTALLATION CHECK SHEET......................27
Indoor unit AIndoor unit B
Indoor unit C
Indoor unit D Outdoor unit
Combination example
Model Combinations
Combine indoor and outdoor units only as listed
below.
Model No.
Indoor Unit Outdoor Unit
CS-MKE7NKU CU-3KE19NBU
CS-MKE9NKU CU-4KE24NBU
CS-MKE12NKU CU-4KE31NBU
CS-MKE18NKU
CS-MKE24NKU
CS-MKE9NB4U
CS-MKE12NB4U
CS-KE18NB4UW
Power Source:
60 Hz, single-phase, 230 / 208 VAC 
						

							IMPORTANT! 
Please Read Before Starting
This air conditioning system meets strict safety and operating
standards. As the installer or service person, it is an important
part of your job to install or service the system so it operates
safely and efficiently. 
For safe installation and trouble-free operation, you
must:

Carefully read this instruction booklet before beginning.

Follow each installation or repair step exactly as shown.

Observe all local, state, and national electrical codes.

Pay close attention to all warning and caution notices
given in this manual.
This symbol refers to a hazard
or unsafe practice which can
result in severe personal injury
or death.
This symbol refers to a hazard
or unsafe practice which can
result in personal injury or prod-
uct or property damage.
If Necessary, Get Help
These instructions are all you need for most installation
sites and maintenance conditions. If you require help for a
special problem, contact our sales / service outlet or your
certified dealer for additional instructions. 
In Case of Improper Installation
The manufacturer shall in no way be responsible for improp-
er installation or maintenance service, including failure to
follow the instructions in this document. 
SPECIAL PRECAUTIONS
When Wiring
ELECTRICAL SHOCK CAN CAUSE SEVERE
PERSONAL INJURY OR DEATH. ONLY A
QUALIFIED, EXPERIENCED ELECTRICIAN
SHOULD ATTEMPT TO WIRE THIS SYSTEM. 

						

							4
1-2.  Accessories Supplied with Unit 
Table 1
1-3.  Optional Copper Tubing Kit
Copper tubing for connecting the outdoor unit to the
indoor unit is available in kits which contain the narrow
and wide tubing, fittings and insulation. Consult your
nearest sales outlet or air conditioning workshop.
1-4.  Type of Copper Tube and Insulation Material
If you wish to purchase these materials separately from
a local source, you will need:
1. Deoxidized annealed copper tube for refrigerant tub-
ing as detailed in Table 2.
Cut each tube to the appropriate lengths 1 to 14
(30 cm to 40 cm) to dampen vibration between units.2. Foamed polyethylene insulation for the specified
copper tubes as required to precise length of tubing.
Wall thickness of the insulation should be not less
than 5/16 (8 mm).
3. Use insulated copper wire for field wiring. Wire size
varies with the total length of wiring. 
Refer to 5. Wiring Instructions for details.
1. Refrigeration (armored) tape
2. Insulated staples or clamps for connecting wire
(See local codes.)3. Putty
4. Refrigeration lubricant
5. Clamps or saddles to secure refrigerant tubing
1Packed in the outdoor unit.  4 each Labels for inter-unit
cable and tubeCushion rubber  4  Parts Figure Q’ty Parts Figure Q’ty Parts Figure Q’ty 
Reducer
(3/8"    1/2")CU-3KE19NBUCU-4KE24NBU
CU-4KE31NBU
2 1ABCDReducer
(1/2"    3/8")
CAUTIONCheck local electrical codes
and regulations before
obtaining wire. Also, check
any specified instructions or
limitations.
ModelNarrow Tube Wide TubeOuter Dia. Thickness Outer Dia. Thickness
CS-MKE7NKU, CS-MKE9NKU, CS-MKE12NKU1/4 (6.35 mm) 0.0314 (0.8 mm) 3/8 (9.52 mm) 0.0314 (0.8 mm)
CS-MKE18NKU1/4 (6.35 mm) 0.0314 (0.8 mm) 1/2 (12.70 mm) 0.0314 (0.8 mm)
CS-MKE24NKU1/4 (6.35 mm) 0.0314 (0.8 mm) 5/8 (15.88 mm) 0.0393 (1.0 mm)
CS-MKE9NB4U, CS-MKE12NB4U1/4 (6.35 mm) 0.0314 (0.8 mm) 3/8 (9.52 mm) 0.0314 (0.8 mm)
CS-KE18NB4UW1/4 (6.35 mm) 0.0314 (0.8 mm) 1/2 (12.70 mm) 0.0314 (0.8 mm)
Table 2
1-5.  Additional Materials Required for Installation
1.  General
This booklet briefly outlines where and how to install the air conditioning system. Please read over the entire set of instruc-
tions for the indoor and outdoor units and make sure all accessory parts listed are with the system before beginning.
If the electric wiring diagram does not appear in this manual, please check for the diagram on the indoor unit.
1-1.  Tools Required for Installation (not supplied)
1. Standard screwdriver
2. Phillips head screwdriver
3. Knife or wire stripper
4. Tape measure
5. Carpenter’s level
6. Sabre saw or key hole saw7. Hacksaw
8. Core bits
9. Hammer
10. Drill
11. Tube cutter
12. Tube flaring tool13. Torque wrench
14. Adjustable wrench
15. Reamer (for deburring)
16. Vacuum pump (For R410A)
17. Manifold valve