Electronic Expansion Valve Control; Step Control Of Outdoor Fans - Daikin VRV RXYMQ-A Series Service Manual

Normal Control
5.5

Electronic Expansion Valve Control

Electronic expansion valve Y1E
 Cooling: electronic expansion valve is used only at fully closed or fully open condition:
 Heating: electronic expansion valve is used in PID control suction superheat:
5.6

Step Control of Outdoor Fans

Used to control the revolutions of outdoor fans in the steps listed in table below, according to
condition changes.
* When the system detects that outdoor air temperature (Ta) reaches 41°C or more, the control
of fan revolutions will be changed to 1,060 rpm automatically.
Note(s)
 Table shown above is for external static pressure level 0. In case of high external static
 When capacity priority mode is set, values may differ.
58
 Compressor(s) OFF: fully closed (0 pulse).
 Compressor ON:
 Fully open (480 pulses)
 Normally, the control is used to reduce the PCB temperature.
Compressor
0 Hz
Main
480
Y1E
pulses
0
 Compressor(s) OFF: fully closed (0 pulse).
 Compressor ON:
 At startup: closed (check suction pressure drops)
 Modulated opening by:
- Suction superheat = accumulator inlet °C – evaporating temperature.
- Discharge superheat = discharge compressor °C – condensing temperature.
- Preventive change when compressor capacity step changes.
- Limited opening when condensing temperate exceeds target condensing.
Compressor
0 Hz
Main
480
Y1E
pulses
0
Step No. RXYMQ4AVMK
Cooling
0 0
1 200
2 250
3 300
4 360
5 420
6 490
7Y 560
7X 630
8 700
pressure, the unit will re-adjust fan revolutions automatically and values may differ.
Fan revolutions (rpm)
Heating Cooling
0 0
200 440
250 440
300 440
370 440
440 480
515 550
590 650
670 830
750 960*
SiME332106E
RXYMQ4-6AYFK
Heating
0
440
440
440
440
550
660
780
940
1,060
Part 4 Functions and Control