Daikin VRV III REYQ8PY1, Service Manual

Page: 119 / 452

Basic Control Si37-701
108 Function
2.3 Electronic Expansion Valve PI Control
Main electronic expansion valve EVM control
When the outdoor unit heat exchanging is performed via the evaporator (20SA is set to ON),
this function is used to exert PI control on the electronic expansion valve (Y1E or Y3E) so that
the evaporator outlet superheated degree (SH) will become constant.
Subcooling electronic expansion valve EVT control
In order to make the maximum use of the subcool heat exchanger, this function is used to exert
PI control on the electronic expansion valve (Y2E, Y5E or Y3E) so that the evaporator-side gas
pipe superheated degree (SH) will become constant.
Refrigerant charge electronic expansion valve EVJ control
While in automatic refrigerant charge mode, this function is used to exert PI control on the
opening degree of the electronic expansion valve (Y2E or Y4E) in response to outdoor
temperature and close the valve after the completion of refrigerant charge.
For normal operation, fully open this electronic expansion valve.
2.4 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.
SH = Tg - Te SH: Evaporator outlet superheated degree
(°C)
Tg : Suction pipe temperature (°C) detected
by the heat exchanger gas pipe
thermistor R2T.
Te : Low pressure equivalent saturated
temperature (°C)
SH = Tsh - Te SH: Evaporator outlet superheated degree
(°C)
Tsh:Suction pipe temperature (°C) detected
by the subcool heat exchanger outlet
thermistor R5T
Te: Low pressure equivalent saturated
temperature (°C)
STEP No.
Fan revolutions (rpm)
Single type Multiple type
8HP 10HP 12HP 14HP 16HP M8 M10 M12 M14 M16
0 0 0 0 0 0 0 0 0 0/0 0/0
1 285/255 285/255 285/255 285/255 285/255 350 350 350 230/0 230/0
2 315/285 315/285 315/285 360/315 360/315 370 370 370 380/0 380/0
3 360/330 360/330 360/330 395/365 395/365 400 400 400 290/260 290/260
4 430/400 430/400 430/400 480/440 480/440 450 450 450 375/345 375/345
5 590/560 590/560 590/560 560/530 560/530 540 560 560 570/540 570/540
6 690/660 690/660 690/660 760/730 760/730 610 680 680 720/690 720/690
7 820/790 820/790 820/790 960/930 960/930 680 710 710 910/880 910/880
8 920/890 920/890 951/931 1125/1095 1155/1125 710 750 775 1091/1061 1091/1061
9 920/890 920/890 1020/990 1125/1095 1200/1170 796 821 870 1136/1106 1136/1106
Fan1/Fan2 Fan1/Fan2 Fan1/Fan2 Fan1/Fan2 Fan1/Fan2 Fan1/Fan2 Fan1/Fan2