Panasonic Cs W18bd3n Cs W24bd3n Cs W28bd3n Series Repair Manual

If test operation does not proceed correctly
Carry out test operation after approximately 6 hours have passed
since the power was turned on (crankcase heater is energized). If
operation is started by using the remote control within 1 minute of
turning on the power, the outdoor unit settings will not be made
correctly and correct operation will not be possible.
If the following symptoms occur after turning on the power,
check the wiring connections once more.
 
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• •  • 
For standard installation...

 1. The main power is turned on while the transmission
wires between the indoor unit(s) are not connected
(open circuit at section A)
Symptom:
Nothing abnormal appears on the remote control
display . If operation is then started in this condition, the
combination of the 43BB outdoo r unit and the 40U
indoor unit (master unit) will cause abnormal operation
to occur.
↓
If operation continues, an abnormality will occur on the
refrigeration cycle and operation will stop.
 
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− −  − 
Remote control. . ....

 1. The main power is turned on while the transmission
wires between the indoor unit and the outdoor unit are
not connected (open circuit at section A).
Symptom:
Operation of indoor unit No. 1 and indoor unit No. 3 is
possible.
However, “CHECK” flashes in the remote control unit
display for 3-5 minutes after the main power is turned
on.
 
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− −  − 
Remote control. . . “CHECK” flashes.
 
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Indoor unit No. 2 . . . LED2 on the printed circuit
board flashes (both master and slave units)....

 1. Automatic address setting (no need to have dip-switch set)
If the wiring connected properly as above example, the address is set automatically by the main powersupply. An indoor unit
with remote control will be set as the master. If the power source is installe d to indoor units and outdoor separately, turn on the
switch as the following procedure: outdoo r unit, indoor unit with control, and other indoor units.
When theslave units do not operate (when address cannot be set)
Important: The address...

 1. Automatic address setting (no need to have dip-switch set)
If the wiring connected properly as above example, the AC numbe rs are set automatically by the main powersupply . An indoor
unit with remote control will be set as the master.
If the power source is installe d to indoor units and outdoo r separately, turn on the switch as the following procedure: outdoo r
unit, indoor unit with controller, and other indoor units. The AC numbe r will be set at random.
 2. Manua l address setting (by...

Procedures of deleting memory attwincontrol system
Procedure of deleting memory at group control system  1. Set the “OFF” position for main power supply switch.
 2. Set the “ON” position for No. 8 pin of dip switch (DSW1) on indoor unit P.C. board.
 3. Take main power supply switch “ON” for one minute, and then main power supply switchoff.
 4. Set the “OFF” position for No. 8 pin of dip switch (DSW1).
 1. Set the “OFF” position for main power supply switch.
 2. Set the “ON” position for No. 1 pin to No....

Emergencyoperation
 
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• •  • 
Emergency operation of outdoor unit
Emergency operation can be carried out by setting the
DSW1 switch on the printed circuit board inside the
outdoo r unit to the EMERGENCY position. However,
emergency operation is only carried out when an
abnormality is detected by the indoor/outdoor
temperature thermistors.
The resistance values of each thermistor are measured
as shown in the table below to determine if there is an
abnormality.
Thermistor resistance table
Temperatu...

24 CONTROL
24.1. Description of basic Functions
24.1.1. Cooling mode operation time chart
(*1)
Outdoor unit fan start control during cooling
At the start of cooling mode and drying mode operation, the outdoo r unit heat exchan ger outlet temperature is detected in order
to set the fan speed.
Operation is carried out at the fan speed detected for 30 seconds.
After 30 seconds, the heat exchan ger outlet temperature is detected and the outdoo r unit fan speed is changed automatically .
(*2)
Cooling low...

24.2. Freezing prevention control
 1. Operation
During cooling mode operation, after 9 minutes have passed since the compressor turned on, the outdoor units stops operating
when the temperature detected by the indoor unit pipe temperature sensor is 2°C or lower.
The indoor unit continues operating at the fan speed set by the remote control unit. (The remote control unitdisplay does not
change.)
 2. Cancelling
This control is cancelled when the temperature detected by the indoor unit pipe temperature...

(*2)
Outdoor unit fan control during heating mode operation
Under conditions when the compressor is on during heating mode operation (except during defrosting and when the liquid bypass
valve is on), the outdoor unit fan is controlled by means of input (CN2) indicating whether the contact of the heating pressure switch
on the outdoor unit circuit board is open or closed. (At the start of heating mode operation, the fan operates at HI speed.)
24.4. Hot starting
1. When heating mode operation starts
 1....