Winding/Coil Heating Control; Defrost Control (Only In Heating Operation); Compressor Protective Control - Toshiba RAS-3M26S3AV-E Service Manual

Item
5. Winding/Coil When the outdoor temperature is low, the windings/
heating control coils are heated to ensure compressor reliability.
Outdoor temperature To
0˚C
-1˚C
–5˚C
–6˚C
6. Defrost control
(This function removes frost adhered to the outdoor
(Only in heating heat exchanger.)
operation)
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.
Start of heating operation
0' 10' 15'
–5°C
–8°C
–10°C
–20°C
*
* 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)
When Te0 - TE ≥ 2.5 continued for 2 minutes in A zone,
A zone
defrost operation starts.
When the operation continued for 2 minutes in B zone,
B zone
defrost operation starts.
When Te0 - TE ≥ 3 continued for 2 minutes in C zone,
C zone
defrost operation starts.
When the operation continued for 2 minutes in D zone,
D zone
defrost operation starts.
When Te1 - TE ≥ 1 continued for 2 minutes in E zone,
E zone
defrost operation starts.
7. Compressor 1) This control purposes to raise the operation frequency until 36Hz for 2 minutes in order to
protective protect the compressor (Prevention of oil accumulation in the refrigerating cycle) when the status
control that the operation frequency is 36Hz 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.
Operation flow and applicable data, etc.
Operation time
29' 35'
(Minute)
C zone
A zone
B zone
Table 1
Winding/Coil heating is performed when
the following conditions are met.
Condition 1 :
Winding/Coil
When the discharge sensor temperature
heating amount
(Td) is less than 30°C.
OFF
Condition 2 :
When the outdoor sensor temperature (To)
is as shown in the left figure.
20 W
65 W
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.
90' 6 hours
2) Invert (OFF) 4-way valve 10 seconds
after stop of the compressor.
3) The outdoor fan stops at the same time
E zone
when the compressor stops.
4) When temperature of the indoor heat
exchanger becomes 38°C or lower,
stop the indoor fan.
D zone
<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.
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FILE NO. SVM-15074
Description