Winding/Coil Heating Control; Defrost Control (Only In Heating Operation) - Toshiba RAS-M13PKVP-E Service Manual

Item
7. Winding/Coil When the outdoor temperature is low, the windings/coils
heating control are heated to ensure compressor reliability.
Outdoor temperature To
12˚C
11˚C
–5˚C
–6˚C
8. Defrost control (This function removes frost adhered to the outdoor
(Only in heating heat exchanger.)
operation) 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.
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
A zone
defrost operation starts.
When the operation continued for 2 minutes in B zone,
B zone
defrost operation starts.
When Te0 - TE
C zone
defrost operation starts.
When the operation continued for 2 minutes in D zone,
D zone
defrost operation starts.
When Te1 - TE
E zone
defrost operation starts.
Operation fl ow and applicable data, etc.
Operation time
2 9 3 ' ' 5
(Minute)
C zone
A zone
B zone
Table 1
2.5 continued for 2 minutes in A zone,
3 continued for 2 minutes in C zone,
1 continued for 2 minutes in E zone,
Winding/Coil heating is performed when
the following conditions are met.
Condition 1 :
When the discharge sensor temperature
Winding/Coil (Td) is less than 30°C.
heating amount
Condition 2 :
OFF
When the outdoor sensor temperature
(To) is as shown in the left fi gure.
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
90' 4 h o u s r
2) Invert (OFF) 4-way valve 10 seconds
E zone
3) The outdoor fan stops at the same
4) When temperature of the indoor heat
D zone
<Finish of defrost operation>
• Returning conditions from defrost
operation to heating operation
1) Temperature of outdoor heat
2) Temperature of outdoor heat
3) Defrost operation continues for 10
<Returning from defrost operation>
1) Stop operation of the compressor for
2) Invert (ON) 4-way valve approx. 40
3) The outdoor fan starts rotating at
– 37 –
Description
30 seconds.
after stop of the compressor.
time when the compressor stops.
exchanger becomes 38°C or lower,
stop the indoor fan.
exchanger rises to +8°C or higher.
exchanger is kept at +5°C or higher
for 80 seconds.
minutes.
approx. 60 seconds.
seconds after stop of the compressor.
the same time when the compressor
starts.