Download Daikin RQYQ8-48PY1B Specifications

Detailed Control Functions
SiBE341027
2.4.5 Electronic Expansion Valve PI Control
Main electronic expansion valve control
When the outdoor unit heat exchanger is performed via the evaporator, this function is used to exert PI control
on the electronic expansion valve (Y1E) so that the evaporator outlet superheated degree (SH) will become
constant.
SH = Tg - Te
SH: Evaporator outlet superheated degree (°C)
Tg : Suction pipe temperature (°C) detected by the
thermistor R8T.
Te : Low pressure equivalent saturation temperature (°C)
Subcooling electronic expansion valve control
In order to make the maximum use of the subcooling heat exchanger, this function is used to exert PI control
on the electronic expansion valve (Y2E or Y3E) so that the evaporator-side gas pipe superheated degree
(SH) will become constant.
SH = Tsh - Te
SH: Evaporator outlet superheated degree (°C)
Tsh: Suction pipe temperature (°C) detected by the
subcooling heat exchanger outlet thermistor R5T.
Te: Low pressure equivalent saturation temperature (°C)
2.4.6 Step Control of Outdoor Unit Fans
Used to control the revolutions of outdoor unit fans in the steps listed in table below, according to condition
changes.
STEP
No.
0
Fan revolutions (rpm)
RQYQ14PY1B
RQYQ8PY1B RQYQ10PY1B RQYQ12PY1B
MF1
MF2
0
0
0
0
0
RQYQ16PY1B
MF1
0
MF2
0
1
2
350
370
350
370
350
370
230
380
0
0
230
380
230
380
3
4
400
450
400
460
400
460
290
375
260
345
290
375
290
375
5
6
540
610
560
710
560
710
570
720
540
690
570
720
570
720
7
760
870
1091
1061
1091
980
8
Cooling: 796
Heating: 780
Cooling: 821
Heating: 800
Cooling: 821
Heating: 800
870
1136
1106
1136
980
* Figures listed above are all those controlled while in standard mode, which vary when the system is set to high static
pressure or capacity precedence mode.
[Control at a low outdoor temperature during cooling]
Secure the liquid pressure and circulating rate in the indoor unit through high pressure control with the outdoor fan when
the outdoor temperature is low during cooling. Control the fan with the target Tc (high pressure equivalent saturation
temperature) = 34°C
50
Function