8.3.1.17. Freeze Prevention Control
1. When indoor heat exchanger temperature is lower than 2°C continuously for six minutes, compressor will stop operating.
2. Compressor will resume its operation three minutes after the indoor heat exchanger is higher than 10°C.
3. At the same time, indoor fan speed increase +20 rpm compared to its normal operation.
4. If indoor heat exchanger temperature is higher than 10°C for five minutes, the fan speed will return to its normal operation.
8.3.1.18. Dew Prevention Control
a. Purpose
To prevent dew.
b. Control start conditions
When indoor units are ceiling floor, duct and mini-cassette.
c. Control contents
Hz control is carried out according to the dew prevention status transmitted from indoor.
Dew prevention
status (transmitted indoor)
Control contents
Relative control domain MAX domain
0 (it usually controls) Usually, control Usually, control
1 (rise) Relative change control priority On tap up/10 seconds
2 (changeless) Changeless Changeless
3 (down) -2 Hz/10 seconds -2 Hz/10 seconds
Change is once to 10 seconds.
* Once the stand-up went into the down domain by Fcmax as for the Fcmax domain, it shifts to relative changes control domain.
When the higher rank of relative control has this control and the status signal od 2-3 has come out.
Relative change control is stopped and follows directions of spray control.
Priority is given to the which is larger when freeze prevention down status and dew prevention down status are transmitted
simultaneously.
In the case of dew prevention status
0, it is referred to as maxFc.
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