Emergency Operation - Panasonic CS-W24BD2P Service Manual

24 EMERGENCY OPERATION

Emergency operation
• • • • Emergency operation of outdoor unit
Emergency operation can be carried out by setting the
DSW1 switch on the printed circuit board inside the outdoor
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
Temperature
Room temperature
-20°C
-10°C
-5°C
0°C
5°C
10°C
15°C
20°C
25°C
30°C
40°C
50°C
60°C
70°C
80°C
90°C
100°C
The pipe temperature thermistor resistance value are the same
for the indoor and outdoor units.
<When a thermistor abnormality is judged to have
occurred>
Resistance value (kΩ) ± 5%
Pipe temperature
thermistor thermistor
205.8 197.8
114.6 111.9
87.3 85.4
67.0 65.8
51.8 51.0
40.4 39.9
31.7 30.7
25.1 25.0
20.0 20.0
16.1 16.0
10.4 10.6
6.9 7.1
4.7 4.9
___ 3.5
___ 2.5
___ 1.8
___ 1.4
• • • • Set only the thermistor which shows an abnormality to the
condition shown in the table below to carry out emergency
operation
Thermistor
Indoor unit Room temperature
Room temperature
Thermistor
Outdoor unit Discharge
temperature
Heat exchanger
outlet temperature
• • • • Refer to the circuit diagram for the connection locations for
each thermistor.
• • • • If there is an abnormality in the room temperature
thermistor, the temperature will be fixed at 25°C regardless
of the remote control unit display.
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 supplies
for the indoor and outdoor units off and return the DIP
switch to the NORMAL position.
• • • • Self-diagnosis LEDS 4 to 6 will flash during emergency
operation.
84
Cooling mode Heating mode
Fixed at 25°C
Shorted Open
Cooling mode Heating mode
Open Shorted
Shorted Open