Table of Contents
Advertisement
26 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 of 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
thermistor
-20°C
205.8
-10°C
114.6
-5°C
87.3
0°C
67.0
5°C
51.8
10°C
40.4
15°C
31.7
20°C
25.1
25°C
20.0
30°C
16.1
40°C
10.4
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>
− − − − Set only the thermistor which shows an abnormality
to the condition as shown in the table below to carry
out emergency operation.
Resistance value (kΩ) ± 5%
Pipe temperature
thermistor
197.8
111.9
85.4
65.8
51.0
39.9
30.7
25.0
20.0
16.0
10.6
6.9
7.1
4.7
4.9
----
3.5
----
2.5
----
1.8
----
1.4
Thermistor
Indoor unit
Room temperature
Pipe 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 display.
NOTE:
− − − − Any abnormalities detected by the temperature
thermistors are ignored during emergency operation,
therefore, long-term operation in this mode should
be avoided.
− − − − After
emergency
completed and normal operation is to be resumed,
turn off the power supplies for the indoor and
outdoor units and set the DSW1 switch to NORMAL
position.
− − − − Self-diagnosis LEDs 4 to 6 will flash during
emergency operation.
59
Cooling mode
Heating mode
Fixed at 25°C
Shorted
Open
Cooling mode Heating mode
Open
Shorted
Shorted
Open
mode
operation
has
been
Hide quick links:
Advertisement
Table of Contents
