4-15
4
Frost adherence detection
• If the following conditions are satisfied during heating operations, it is regarded as "frost adherence is detected".
• Frost adherence detection is performed in accordance with the ambient temperature (TO) and the outdoor heat exchanger
temperature sensor (C1).
• Frost adherence detection conditions
(a)
Defrosting condition zone (below chart) for consecutive 3 minutes
Defrosting condition zone (below chart) for accumulation of 60 minutes
or
is detected.
Outdoor heat exchanger temperature sensor (C1) < -18 °C (consecutive 20 seconds) (U-50PE1E5 only)
_
or
In case of ambient temperature (TO) > -13°C :
(b)
Following satisfied condition is detected for consecutive 20 seconds.
In case of ambient temperature (TO) < -13°C :
(c) Following satisfied condition is detected for accumulation of over 90 minutes.
Outdoor heat exchanger temperature sensor (C1) < -3 °C
_
Outdoor heat exchanger temperature sensor (C1) < Ambient temperature (TO) - 5 °C (U-50PE1E5 only)
_
-11.4
Y
10
0
-3
-8
-18
X
8) Defrosting Control
This control function removes frost that has adhered to the outdoor heat exchanger during the heating operation.
The control is performed to prevent the deterioration of the heating capabilities attributed to the adherence of
frost, and to prevent the crack or crush of pipes attributed to the accretion of ice.
The following control is performed in accordance with the ambient temperature and the outdoor heat exchanger
temperature sensor (C1).
Overall Flow Chart of Defrosting Control
Normal heating operation
Has frost adherence been
detected?
Has more than 25 minutes
(heating mask time) elapsed?
Heating operation resumed
Yes (elapsed)
Yes (satisfied)
Have the conditions for ending
defrosting been satisfied?
Heating
operation
continued
Heating
operation
continued
Defrosting
operation
continued
Yes (detected)
Defrosting operations commenced
Outdoor heat exchanger temperature sensor (C1) (°C)
Ambient temperature (TO) (°C)
Defrosting condition zone
No
No
No
Heating Mask Time
This refers to the shortest time that heating operations must be performed without defrosting operations being executed.
The mask time for this model is 25 minutes.
*
Defrosting operations will not be commenced until the defrosting mask time has elapsed, even if frost adherence has
been detected.
SM830231-02̲Single̲欧州.indb 15
SM830231-02̲Single̲欧州.indb 15
2014/09/09 21:15:23
2014/09/09 21:15:23