Item | Operation flow and applicable data, etc. |
7.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 |
Start of heating operation
FILE NO.
Description
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, or C zone each. (Table 1)
<Defrost operation>• Defrost operation in A to C zones
1) Stop operation of the compressor for |
20 seconds. |
Outdoor heat exchanger temperature
0’
27˚F
19˚F
−15˚F
10’ 15’ | 29’ | 35’ | Operation time | |
(Minute) | ||||
|
|
|
C zone
A zone
B zone
*
*The minimum value of Te sensor 10 to 15 minutes after start of operation is stored in memory as Te0.
2) | Invert (ON) |
| 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 100°F (38°C) or |
| lower, stop the indoor fan. |
•Returning conditions from defrost operation to heating operation
1) | Temperature of outdoor heat exchanger |
| rises to 46°F (8°C) or higher. |
2) | Temperature of outdoor heat exchanger is |
| kept at 41°F (5°C) or higher for 80 seconds. |
3) | Defrost operation continues for |
| 15 minutes. |
| Table 1 | |
|
| |
A zone | When Te0 - TE ≥ 4.5°F (2.5°C) 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 ≥ 5.4°F (3°C) continued for 2 minutes in | |
C zone, defrost operation starts. | ||
| ||
|
|
1)Stop operation of the compressor for approx. 50 seconds.
2)Invert (OFF)
3)The outdoor fan starts rotating at the same time when the compressor starts.
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