Normal Control
SiME332106E
58
Part 4 Functions and Control
Note(s)
5.5 Electronic Expansion Valve Control
Electronic expansion valve Y1E
Cooling: electronic expansion valve is used only at fully closed or fully open condition:
Compressor(s) OFF: fully closed (0 pulse).
Compressor ON:
Fully open (480 pulses)
Normally, the control is used to reduce the PCB temperature.
Heating: electronic expansion valve is used in PID control suction superheat:
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.
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.
Table shown above is for external static pressure level 0. In case of high external static
pressure, the unit will re-adjust fan revolutions automatically and values may differ.
When capacity priority mode is set, values may differ.
Compressor
Main
Y1E
0 Hz
0
480
pulses
Compressor
Main
Y1E
0 Hz
0
480
pulses
Step No.
Fan revolutions (rpm)
RXYMQ4AVMK
RXYMQ4-6AYFK
Cooling
Heating
Cooling
Heating
0
0
0
0
0
1
200
200
440
440
2
250
250
440
440
3
300
300
440
440
4
360
370
440
440
5
420
440
480
550
6
490
515
550
660
7Y
560
590
650
780
7X
630
670
830
940
8
700
750
960*
1,060
