Panasonic Cs W18bd3p Cs W24bd3p Cs W28bd3p Series Repair Manual

							 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 dip-switchDSW1)
When you set theaddress manua lly, set the dip-switch of the PC board in the indoor unit as follow:
 3. Manua l address setting (by dip-switchDSW1)
When you set theaddress manua lly, set the dip-switch of the PC board in the indoor unit as follow:
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							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. 4 pin of dip switch (DSW1) on indoor unit P.C. board.
(No. 8 pin of dip switch (DSW1)should be “OFF” position)
 3. Take main power supply switch “ON” for one minute, and then main power supply switchoff.
 4. Set the “OFF” position for No. 1, No. 2, No. 3 and No. 4 pin of dip switch (DSW1).
(Important notice)
Above procedures are for deletin g memory on indoor unit P.C. board. And it is not for Address reset.
23.1. Indoor unit P.C. board layout.
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							Emergencyoperation
 
    • 
• •  • 
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 reResistance value (kΩ
)±5%
Room temperature
thermistorPipe temperature
thermistor
-20°C205.8197.8
-10°C114.6111.9
-5°C87.385.4
0°C67.065.8
5°C51.851.0
10°C40.439.9
15°C31.730.7
20°C25.125.0
25°C20.020.0
30°C16.116.0
40°C10.410.6
50°C6.97.1
60°C4.74.9
70°C___3.5
80°C___2.5
90°C___1.8
100°C___1.4
The pipe temperature thermistor resistance value are
the same for the indoor and outdoor units.

 
    − 
− −  − 
Set only the thermistor which shows an abnormality
to the condition shown in the table below to carry out
emergency operation
ThermistorCooling modeHeating mode
Indoor unitRoom temperatureFixed at 25°C
Room temperatureShortedOpen
ThermistorCooling modeHeating mode
Outdoor unitDischarge
temperatureOpenShorted
Heat exchanger
outlet temperatureShortedOpen
 
    − 
− −  − 
Refer to the circuit diagram for the connection
locations for each thermistor.
 
    − 
− −  − 
If there is an abnormality in the roomtemperature
thermistor, the temperature will be fixed at 25°C
regardless of the remote control unitdisplay .
NOTE:
 
    − 
− −  − 
Any abnormalities detected by the temperature
thermistors are ignored during emergency operation,
so that long-term operation in this mode should be
avoided.
 
    − 
− −  − 
After emergency mode operation has been
completed and normal operation is to be resumed,
turn the power supplie s for the indoor and outdoo r
units off and return the DIP switch to the NORMAL
position.
 
    − 
− −  − 
Self-diagnosis LEDS 4 to 6 will flash during
emergency operation.
24 EMERGENCY OPERATION
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							25 CONTROL
25.1. Description of basic Functions
25.1.1. 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 outdoor temperature protection
When theheat exchan ger outlet temperature drops to less than 12°C for a continuous period of 10 minutes, the outdoor unit stops
running.
This is cancelled after 3 minutes (re-start prevention)
 
    • 
• •  • 
Remote control display s and indoor unit operation continue during thistime.
 
    • 
• •  • 
The 10-minute countdown is cleared if the compressor stops or if the temperature at the outdoor unit outlet rises to 13.5°C or
higher.
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							25.2. 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 sensor is 15°C or higher.
(If the outdoor unit stops even though the temperature is 15°C or higher, restart prevention control will activated and the outdoor
unit will not start again for 3 minutes.)
(The 9-minute countdown is cleared while the compressor is stopped.)
(The above illustration shows the operation when there are no conditions for turning the outdoor unit off other than freezing
prevention.)
25.3. Heating mode operation time chart (Heat pump type only)
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							(*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.)
25.4. Hot starting
1. When heating mode operation starts
 1. Start
Hot start control commences heating mode operation starts.
 2. Operation
“PREHEAT” appears on the remote controldisplay . (Other display s remain unchanged.)
At the indoor unit, the indoor unit fan stops. In additio n, during hot starting, the louvre stays at the horizon tal position (angle
0°).
 3. Cancelling
After 1 minute has passed since heating mode operation started, or if the compressor has turned on, hot starting is
cancelled when the temperature detected by the indoor unit pipe temperature sensor is 18°C or higher.
After cancellation, the PREH EAT display on theremote control disapp ears and the louvre operation returns to the previous
setting.
(However, for 2 minutes after cancellation, the indoor unit fan operates at LOW speed, and then returns to the previous
setting.)


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							2. When defrosting is complete
 1. Start
Hot start control commences when defrosting is complete.
 2. Operation
PREHEAT appears on the remote controldisplay . (Other display s remain unchanged.)
At the indoor unit, the indoor unit fan stops. In additio n, during hot starting, the louvre stays at the horizon tal position (angle
0°).
 3. Cancelling
Hot starting is cancelled when the temperature detected by the indoor unit pipe temperature sensor is 18°C or higher, or
after a maximum 1 minute has passed since defrosting was completed.
After cancellation, the PREH EAT display on theremote control disapp ears and the louvre operation returns to the previous
setting.
(However, the indoor unit fan operates at LOW speed for 2 minutes after cancellation, and then returns to the previous
setting.)
< When hot startoperation is cancelled by temperature >
< When hot startoperation is cancelled by time >
25.5. Indoor unit fan control when thermostat is off during heating mode
operation
When the thermostat of the indoor unit turns off during heating mode operation, the indoor unit fan operates for 2 minutes at LOW
and then stops. In additio n, 5 minutes after the thermostat of the indoor unit turns off, the indoor unit fan again runs at LOW for 10
seconds, and at 3-minute intervals after that it switches back to LOW operation for 10 seconds.
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							25.6. Excess heat dissipation for indoor unit
The indoor unit fan continues operating for 30 seconds after heating mode operation turns off in order to dissipa te excess heat.
 1. Whenheating mode operation has stopped
(LOWoperation for 30 seconds)
 2. Whenoperation is set to a mode other than heating by means of the OPERATION MODE switch
 3. If operation starts again during the 30 seconds mentioned in (1) above
(The fan operates at LOW speed for the remainder of the 30 seconds in (1), and then hot start commences.)
25.7. Defrost mode operation time chart
 1. Start and completion of defrosting
 a. Start
During heating mode operation (including automatic heating), after the 45-minute defrostingcycle time has passed,
defrosting starts if the temperature detected by the outdoor unit heat exchan ger outlet sensor is 2°C or lower for a
continuous 5-minute period.
However, if the outdoo r unit fan is stopped, the start of defrosting will be delaye d by 5 minutes.
The defrosting cycle is 50 minutesfrom the start of heating mode operation.
 b. Completion
Defrosting mode operation stops 12 minutes after it starts, or if the temperature detected by the outdoor unit heat exchan ger
outlet sensor is 25°C or higher.
After defrosting is complete, hot starting commences.
 c. Forced defrosting
If P8 on the outdoor unit circuit board is shorted while the compressor is ‘ON’ during heating mode operation and the
temperature detected by the outdoor unit heat exchan ger outlet sensor is 25°C or lower, defrosting is carried out regardless
of the current starting conditions.
 2. Operation
 a. During defrosting, the outdoor unit turns on the compressor and turns off the outdoor unit fan and the reversing valve.
 b. The indoor unit fan operates at LOW for 30 seconds after defrosting starts. After this, the indoor unit fan turns off until
defrosting is complete.
(During defrosting, the louvre of the indoor unit stays at the horizon tal.)
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							25.8. Indoor thermostat characteristic
 1. Thermostat characteristic during cooling and heating modes
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