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7. Winding / Coil
heating
control
When the outdoor temperature is low, the windings / coils are heated
to ensure compressor reliability.
Winding / Coil heating is performed when
the following conditions are met.
Condition 1 :
When the discharge sensor temperature
(Td) is less than 30°C.
Condition 2 :
When the outdoor sensor temperature (To)
is as shown in the left figure.
8. Defrost
control (Only
in heating
operation)
(This function removes frost adhered to the outdoor heat exchanger.)
The temperature sensor of the outdoor heat exchanger (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. The conditions to detect the
necessity of defrost operation differ in A, B,
C, D or E zone each. (Table 1)
<Defrost operation>
• Defrost operation in A to E zones
1) Stop operation of the compressor for
30 seconds.
2) Invert (OFF) 4-way valve 10 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
80 seconds.
3) Defrost operation continues for
10 minutes.
<Returning from defrost operation>
1) Stop operation of the compressor for
approx. 60 seconds.
2) Invert (ON) 4-way valve approx.
40 seconds after stop of the compressor.
3) The outdoor fan starts rotating at the
same time when the compressor starts.
∗
The minimum value of Te sensor 10 to 15 minutes after start of operation is stored in
memory as Te0 and Te1. (–10°C < Te1
≤
10°C)
9. Compressor
protective
control
1) This control purposes to raise the operation frequency until 45Hz for 2 minutes in order to protect the compressor
(Prevention of oil accumulation in the refrigerating cycle) when the status that the operation frequency is 45Hz
or less has continued for 10 hours was calculated. The operation frequency follows the normal indoor command
after controlling.
2) Although the compressor may stop by THERMO-OFF control when the room temperature varies and then
attains the set temperature by this control, it is not abnormal.
3) During this control works, it stopping the operation by the remote controller, the operation does not continue.
Item
Operation flow and applicable data, etc.
Description
Outdoor temperature To
Winding/Coil
heating amount
OFF
40 W
40 W
12
˚
C
11
˚
C
–5
˚
C
–6
˚
C
Start of heating operation
Operation time
(Minute)
C zone
A zone
B zone
D zone
E zone
4 hours
90’
0’
10’15’
29’ 35’
–5°C
–8°C
–10°C
–20°C
Out
door hea
t
exchang
er temper
ature
Table 1
A zone
When Te0 - TE
≥
2.5 continued for 2 minutes in A zone, defrost
operation starts.
B zone
When the operation continued for 2 minutes in B zone, defrost
operation starts.
C zone
When Te0 - TE
≥
3 continued for 2 minutes in C zone, defrost
operation starts.
D zone
When the operation continued for 2 minutes in D zone, defrost
operation starts.
E zone
When Te1 - TE
≥
1 continued for 2 minutes in E zone, defrost
operation starts.