Si10-417
Troubleshooting
Service Diagnosis
35
5.2 Outdoor Unit
5.2.1 Anti-icing Function
Remote
Controller
Display
A5
Method of
Malfunction
Detection
Indoor unit icing, during cooling operation, is detected by
checking the temperatures sensed by the indoor unit
heat exchanger temperature thermistor and room
temperature thermistor that are located in a shut-down
room.
At another room (the indoor unit is normal), “
UH
” is
displayed on the remote controller.
Malfunction
Decision
Conditions
In the cooling mode, the following conditions (A) and (B)
are kept together for 5 minutes.
(A) Indoor unit heat exchanger temperature
≤
–1°C
(B) Indoor unit heat exchanger temperature
≤
Room
temperature –10°C
If the indoor unit anti-icing function is activated four
times continuity, the system will be shut down.
(The 4-time counter will reset itself if any of the
following errors does not occur during the compressor
running time (total time): OL, radiation fin temperature
rise, insufficient gas, and compressor lock.)
<Total 60 minutes>
Supposed
Causes
Wrong wiring or piping
Ev malfunctioning in each room
Short-circuit
Indoor unit heat exchanger temperature thermistor
abnormality
Room temperature thermistor abnormality
Si10-417.fm Page 35 Wednesday, September 22, 2004 6:38 PM
