Toshiba RAS-M13PKVP-E - Defrost Control (Only in Heating Operation); Winding;Coil Heating Control

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Item Operation fl ow and applicable data, etc. Description
7. Winding/Coil
heating control
When the outdoor temperature is low, the windings/coils
are heated to ensure compressor reliability.
12˚C
11˚C
–5˚C
–6˚C
OFF
20 W
65 W
Outdoor temperature To
Winding/Coil
heating amount
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 fi gure.
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.
•
•
–5°C
0’
sruoh4’53’92 90’
–8°C
–10°C
–20°C
Operation time
(Minute)
Start of heating operation
*
Outdoor heat
exchanger temperature
C zone
A zone
D zone
E zone
B zone
10’ 15’
* 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)
Table 1
A zone
B zone
C zone
D zone
E zone
When Te0 - TE r 2.5 continued for 2 minutes in A zone,
defrost operation starts.
When the operation continued for 2 minutes in B zone,
defrost operation starts.
When Te0 - TE r 3 continued for 2 minutes in C zone,
defrost operation starts.
When the operation continued for 2 minutes in D zone,
defrost operation starts.
When Te1 - TE r 1 continued for 2 minutes in E zone,
defrost operation starts.