Four-Way Valve Function Compensation - Daikin FTK25JVE9 Service Manual

Si04-115
1.16

Four-Way Valve Function Compensation

Outline When the initial start of compressors is required after power is on or at operation mode's
alteration (Cooling/Dry ↔ Heating) that the a switch-over of a four-way valve takes place, it
secures the necessary differential pressure by restricting the operation frequency in the lower
limit in a certain period, and the switch-over action is ensured.
Processing 1. If a four-way valve is OFF when compressors stop, it will be ON at this time.
2. If a four-way valve was ON when compressors operated in the last time, it will be ON at this
3. At the start of compressors.
4. At the initial start of compressors after power is reset.
In case 1. and 3. are under the simultaneous condition of AND (it indicates Cooling) or 2. and 3
are under the simultaneous satisfaction of AND (it indicates Heating), or condition 4. is adapted,
the processing applies 45 seconds after compressors begin operating and to set 66 Hz for the
lower limit of operation frequency.
Main Function
time.
General Functionality
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