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1
Mini VRF SYSTEM
Control Functions
3. Special Controls
(a)
(b)
*
(1)
3-4-3. Frost detection
Frost is not detected at the outdoor unit heat exchanger for 5 minutes after operation starts.
Frost is detected when either Condition 1 or 2 below is met.
Condition 1:
L2 line or below is detected twice,
each time continuously for 4 minutes,
when the compressor is operating.
each time continuously for 4 minutes,
when the compressor is operating.
Condition 2:
L1 line or below is detected for a total
of 60 minutes when the compressor is
operating.
of 60 minutes when the compressor is
operating.
Condition 3:
Regardless of this figure, the defrosting
will be made even if the liquid temperature
lower than -3°C for 90 minutes continuously.
It is also possible to avoid this
performance. If you adjust the desired
setting, follow the steps below.
will be made even if the liquid temperature
lower than -3°C for 90 minutes continuously.
It is also possible to avoid this
performance. If you adjust the desired
setting, follow the steps below.
-3°C
EEPROM "CA" -3, -6 ~ -30
The setting of "-3°C" can be
changed to "-6 ~ -30°C" .
changed to "-6 ~ -30°C" .
The setting of "90 minutes." can be
changed to "0 ~ 120 minutes".
changed to "0 ~ 120 minutes".
"CA" becomes ineffective.
3-4-4.Defrost mask time
The next defrost operation will not start until the defrost mask time (= 35 minutes) has elapsed following the
previous defrost operation.
previous defrost operation.
While defrost control is in effect, if all indoor units stop, or if the outdoor unit is restarted after it was stopped
for protective control or a similar reason, then defrost control may start again after a minimum of 10 minutes.
for protective control or a similar reason, then defrost control may start again after a minimum of 10 minutes.
3-4-5.General flow of reverse cycle defrost
General flow of reverse cycle defrost control
Reverse cycle defrost control follows this flow process:
3-4-6.Defrost end judgment conditions
Defrost ends when the below defrost end conditions are met.
Condition 1:
Condition 2:
Defrost end judgment occurs when the temperature at the temperature sensor installed on the
outdoor heat exchanger is 10°C or higher (or has been 6°C or higher continuously for 1 minute).
outdoor heat exchanger is 10°C or higher (or has been 6°C or higher continuously for 1 minute).
When the maximum defrost time shown in the table above has elapsed, defrost end judgment
occurs.
occurs.
–25
–23
–10
The frost detection area is
located under the thick lines
located under the thick lines
L2
L1
–3
–21.4
–8
–1
6
10
Defrosting operation
end temperature
end temperature
(The end temperature is
different from the above
detection temperature.)
different from the above
detection temperature.)
Heat exchange liquid temperature °C
External temperature °C
Fig. 1-4
Control time
Max. 12 minutes (stops once before and after control)
Outdoor units
Operates at a compressor frequency of 75 Hz. The outdoor fan stops.
Electronic
control valve
control valve
All indoor units operate at a fixed pulse according to the indoor unit capacity.
Indoor
units
units
Fan
The fan stops.
Normal
operation
1 minute
stop
Reverse cycle defrost
control (Max. 12 minutes)
1 minute
stop
Normal
operation
90 mins.
EEPROM "A7" 0 ~ 120 minutes.
In case of "FF" setting, the
setting becomes ineffective.
In case of "FF" setting, the
setting becomes ineffective.
SM830195-03_Mini VRF SYS.indb 10
SM830195-03_Mini VRF SYS.indb 10
2014/09/04 18:14:07
2014/09/04 18:14:07
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