Panasonic Cu 3ks19nbucu 4ksxxnbu Technical Service Manual

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2-6.Diagram of Outdoor Unit Installation
Never install only a single indoor unit.
Be sure to connect indoor and outdoor units only in
combinations that are listed in the catalog or in the
combination table that was provided with the outdoor unit. 
(Use caution. Connecting any other model may result in
operation failure and malfunction.) 
The dimensions indicated by    in the figure below are  
spaces that are required in order to maintain
performance. Install in a location where the dimensions...

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3.  Installation Process
3-1.Embedding the Tubing and Wiring

Do not connect tubes to locations that are embedded.

Be sure to bind refrigerant tubing and inter-unit cables
together with vinyl tape.

The power cable must be obtained on-site. 
(#12: Less than 85 ft.) 
# ... AWG (American Wire Gauge)

Be sure to apply the provided labels to both ends of
the inter-unit cables to prevent miswiring.

Securely seal the end of embedded tubing with vinyl
tape in order to prevent dirt or moisture entry.

In...

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When reaming, hold the tube end downward and be sure that
no copper scraps fall into the tube. (Fig. 9)
(3) Remove the flare nut from the unit and be sure to mount
it on the copper tube.
(4) Make a flare at the end of copper tube with a flare tool.*
(Figs. 10 and 11) 
(*Use “RIDGID” or equivalent.)
A good flare should have the following characteristics:

inside surface is glossy and smooth.

edge is smooth.

tapered sides are of uniform length.
3-4.  Caution before Connecting Tubes Tightly
a) Be sure...

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3-6.  Insulation of Refrigerant Tubing
To prevent heat loss and wet floors due to dripping of con-
densation,both tubes must be well insulated with a
proper insulation material.
The thickness of the insulation should be a minimum 5/16
(8 mm). (Fig. 16)
For wall-mounted units
After connecting the refrigerant tubing to the outdoor unit
and performing a leak test on the connecting part, insulate it
with the tubing insulation. (Fig 17a)
For ceiling-mounted cassette units
Wind the insulation tape around...

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4.  Air Purging
Air and moisture remaining in the refrigerant system have
undesirable effects as indicated below. Therefore, they
must be purged completely.

pressure in the system rises

operating current rises

cooling efficiency drops

moisture in the air may freeze and block capillary tubing

water may lead to corrosion of parts in the refrigerant
system

Air Purging with a Vacuum Pump 
(for Test Run)

In order to protect the earth’s environment, be sure to use
a vacuum pump to perform the air...

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Cap tightening torque:
170 – 215 lbs·in
(200 – 250 kgf·cm)
(Tighten by hand, then 
use a wrench to turn 
 approximately 
      45°.) Stopper
Spindle
Service port
Screw diameter: 1/2
UNF 20 threads
Valve core
Cap nut tightening torque:
60 – 95 lbs·in
(70 – 110 kgf·cm)
(Tighten by hand, then use a 
wrench to turn approximately 30 .)

External diameter of service port
R410A: 5/16
NOTE
Fig. 21

When using a hex wrench to open the spindle, an
extremely small amount of refrigerant may leak. 
This does not...

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Pump Down

When relocating or disposing of the air conditioner, request this
service from the dealer where the unit was purchased, or from an
appropriate agent. Perform pump-down as described below.
What is pump-down?

Pump-down refers to recovering the refrigerant gas from the refrig-
erant cycle at the outdoor unit. This work must be performed dur-
ing cooling operation. The refrigerant gas cannot be recovered 
during heating operation.

During winter, or if the temperature sensor prevents cooling...

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5.  Wiring Instructions
5-1.  General Precautions on Wiring
(1) Before wiring, confirm the rated voltage of the unit as
shown on its nameplate, then carry out the wiring 
closely following the wiring diagram.
(2) Provide a power outlet to be used exclusively for each
unit, with a power supply disconnect and circuit break-
er for overcurrent protection provided in the exclusive
line.
(3) To prevent possible hazard due to insulation failure, 
the unit must be grounded.
(4) Each wiring connection must be...

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WARNING

Be sure to comply with local codes on running the
wire from the indoor unit to the outdoor unit (size
of wire and wiring method, etc.).

Each wire must be firmly connected.

No wire should be allowed to touch refrigerant
tubing, the compressor, or any moving part.

Be sure to connect power wires correctly match-
ing up numbers on terminals of the outdoor unit
and respective indoor units A – D.
CAUTION

Be sure to connect the power supply line to the
outdoor unit as shown in the wiring...

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When connecting each power wire to the corresponding
terminal, follow the instructions “How to connect wiring
to the terminal” and fasten the wire securely tight with
the fixing screw of the terminal plate.
How to connect wiring to the terminal
a) For Indoor Unit
(1) Cut the wire end with a cutting pliers, then strip the
insulation to expose the wire about 9/32 (7 mm).
See the label (Fig. 26) near the terminal plate.
(2) Using a screwdriver, loosen the terminal screw on
the terminal plate.
(3) Insert...