Heating Mode - Hitachi RPIL-1.0PNN1DH Service Manual

5. CONTROL LOGIC DESCRIPTION

5.3 Heating Mode

Indoor fan running rules:
In several minutes after the heating mode is started, the fan of the indoor unit will not run until
the heat exchanger of the indoor unit reaches a high enough temperature. That is because
cold air prevention system is operating. After several minutes, the speed can be selected as
high, (medium), low and auto.
The auto fan:
T1 is indoor room temperature. Ts is setting temperature.
High
Medium
Low
2 Ts-T1
4
0
DC-Inverter outdoor unit：
Outdoor fan running rules:
Once the outdoor fan start up, it will follow the below rules:
Single outdoor fan: First, it will run in an invariable speed for a short time; Then it will regulate
the speed by the indoor-coil temperature.
Double outdoor fan: If it has two outdoor fans, the upper fan regulates the speed by the rules,
and the downer fan speed lower than the upper fan speed for 30rpm~60rpm.
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