Specifications
Detailed Control Functions SiBE341027
50 Function
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.
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.
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.
* 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
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)
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)
STEP
No.
Fan revolutions (rpm)
RQYQ8PY1B RQYQ10PY1B RQYQ12PY1B
RQYQ14PY1B RQYQ16PY1B
MF1 MF2 MF1 MF2
00000000
1 350 350 350 230 0 230 230
2 370 370 370 380 0 380 380
3 400 400 400 290 260 290 290
4 450 460 460 375 345 375 375
5 540 560 560 570 540 570 570
6 610 710 710 720 690 720 720
7760
Cooling: 821
Heating: 800
870 1091 1061 1091 980
8
Cooling: 796
Heating: 780
Cooling: 821
Heating: 800
870 1136 1106 1136 980