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 Resistance value (k
Ω
)±5%
Room temperature
thermistor
Pipe temperature
thermistor
-20°C 205.8 197.8
-10°C 114.6 111.9
-5°C 87.3 85.4
0°C 67.0 65.8
5°C 51.8 51.0
10°C 40.4 39.9
15°C 31.7 30.7
20°C 25.1 25.0
25°C 20.0 20.0
30°C 16.1 16.0
40°C 10.4 10.6
50°C 6.9 7.1
60°C 4.7 4.9
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.
<When a thermistor abnormality is judged to have
occurred>
•
• •
•
Set only the thermistor which shows an abnormality to the
condition shown in the table below to carry out emergency
operation
Thermistor Cooling mode Heating mode
Indoor unit Room temperature Fixed at 25°C
Room temperature Shorted Open
Thermistor Cooling mode Heating mode
Outdoor unit Discharge
temperature
Open Shorted
Heat exchanger
outlet temperature
Shorted Open
•
• •
•
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.
24 EMERGENCY OPERATION
84
To Next Page
Loading...
Need help?
General
