Daikin RQYQ140-180PY1 Service Manual page 67

SiBE341001
[Single room heating under mixed cooling and heating conditions → cooling]
First, close all of the indoor unit electronic expansion and BS unit electronic expansion valves Y2E, Y3E, Y4E and Y5E
under the heating operation condition.
Next, open the electronic expansion valve Y3E and perform an equalizing operation. Subsequently, the electronic
expansion valve Y5E opens and the indoor unit electronic expansion valve adjusts the opening extent to become a
cooling circuit. The changeover time is about 6 minutes. (However, this can be shortened from 6 minutes to 4 minutes
depending on the onsite setting.)
(1) Heating operation
(2) Pressure equalizing
(3) Cooling operation
Function
Indoor Unit
Heating
Unit
Indoor Unit
(Close)
Pressure
equalizing
Indoor Unit
Cooling
Unit
BS Unit
Liquid pipe
Y1E
Y2E
HP / LP gas pipe
Y4E
Y5E
Suction gas pipe
Y3E
BS Unit
Liquid pipe
Y1E
Y2E (Close)
HP / LP gas pipe
Y4E (Close)
Y5E (Close)
Suction gas pipe
Y3E (Open)
BS Unit
Liquid pipe
Y1E
Y2E
HP / LP gas pipe
Y4E
Y5E
Suction gas pipe
Y3E
Detailed Control Functions
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