Daikin RQYQ140-180PY1 Service Manual page 66

Detailed Control Functions
2.7.5 Cooling/heating mode changeover
[Single room cooling under mixed cooling and heating conditions → heating]
First, close all of the indoor unit electronic expansion valve and BS unit electronic expansion valves Y2E, Y3E, Y4E and
Y5E under the cooling operation condition.
Next, open the electronic expansion valve Y2E and perform an equalizing operation. Subsequently, both the electronic
expansion valve Y4E and the indoor unit electronic expansion valve open to become a heating 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) Cooling operation
(2) Pressure equalizing
(3) Heating operation
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Indoor Unit
Cooling
Unit
Indoor Unit
(Close)
Indoor Unit
Heating
Unit
BS Unit
Liquid pipe
Y1E
Y2E
HP / LP gas pipe
Y4E
Y5E
Suction gas pipe
Y3E
BS Unit
Liquid pipe
Y1E
Y2E (Open)
HP / LP gas pipe
Y4E (Close)
Y5E (Close)
Suction gas pipe
Y3E (Close)
BS Unit
Liquid pipe
Y1E
Y2E
HP / LP gas pipe
Y4E
Y5E
Suction gas pipe
Y3E
SiBE341001
Function