Item
Operation flow and applicable data, etc.
Description
7. Defrost control
(Only in heating
operation)
(This function removes frost adhered to the outdoor
heat exchanger.)
The temperature sensor of the outdoor heat
ex-changer (TE sensor) judges the frosting status of
the outdoor heat exchanger and the defrost
operation is performed with 4-way valve reverse
defrost system.
The necessity of defrost operation is
detected by the outdoor heat exchanger
temperature (TE) and outdoor air
temperature (TO). The conditions to
detect the necessity of defrost operation
differ in A, B, C, D or E zone each. And
starting of defrost operation of each
zone are explain on Table-1.
Start of heating operation
Table 1
Table 2
Heating operation
Model
(time)
RAS-25J2AVSG-ND
1
RAS-35J2AVSG-ND
1
a
43
b
41
c
31
d
70
e
90
*
**
D zone
A zone
B zone
C zone
E zone
TE (°C) 0
10
15
c
b
a
d
e
-7 °C
-10 °C
-0°C
-3 °C
TO
-25 °C
* The minimum TE value and T
O
value between 10 and 15 minutes after heating operation
has
started are stored in memory as TE0 and TO0, respectively.
*
*
When TO < -10°C, TE are not considered.
Defrost zone
In normal TO
In abnormal TO ***
A zone
TO> -10
°
C
&
(TE0-TE)-(TO0-TO)≥3°C & SH-SH0≤2
TE0-TE≥3°C & SH-SH0≤2
B zone
TO>
-10 °C & (TE0-TE)-(TO0-TO)≥2°C & SH-SH0≤2
TE0-TE≥2°C & SH-SH0≤2
C zone
To>
-10 °C & TE≤ -25°C & SH-SH0≤2
D zone
TO > -10
°
C & Accumulate heating operation time > e minute & TE < 0
°
C
E zone
TO< -10
°C & accumulate heating operation time > e min
No E zone
*** If TO sensor is
abnormal
, TO value is fixed at -10°C.
<Returning from defrost operation>
1)
Stop operation of the compressor for
approx.
5
0 seconds.
2)
Invert (O
FF
) 4-way valve approx.
4
0
seconds after stop of the
compressor.
3)
The outdoor fan starts rotating at the
same time when the compressor starts.
<Defrost operation>
• Defrost operation in A to C zones
1)
Stop operation of the compressor for
2
0 seconds.
2)
Invert (O
N
) 4-way valve
1
0 seconds
after stop of the compressor.
3)
The outdoor fan stops at the same time
when the compressor stops.
4)
When temperature of the indoor heat
exchanger becomes 38°C or lower,
stop the indoor fan.
<Finish of defrost operation>
• Returning conditions from defrost
operation to heating operation
1)
Temperature of outdoor heat exchanger
rises to +8°C or higher
.
2)
Temperature of outdoor heat exchanger
is
kept at +
5
°C or higher for
8
0 seconds.
3)
Defrost operation continues for
1
5
minutes.
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