mundoclima Aerotherm V17 Series, Service Manual

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4.4 Four way Valve Control
The four-way valve is used to change the direction of refrigerant flow through the water side heat exchanger in order to
switch between cooling and heating/DHW operations. Refer to Figures 2-3.1 and 2-3.2 in Part 2, 3 “Refrigerant Flow
Diagrams”.
During heating and DHW operations, the four-way valve is on; during cooling and defrosting operations, the four-way
valve is off.
4.5 Electronic Expansion Valve Control
The position of the electronic expansion valve (EXV) is controlled in steps from 0 (fully closed) to 480 (fully open).
ƒ
At power-on:
y
The EXV first closes fully, then moves to the standby position (304 (steps)). After 30 seconds the EXV moves to an
initial running position, which is determined according to operating mode and outdoor ambient temperature.
After a further 150 seconds, the EXV is controlled according to suction superheat and discharge temperature.
Once a further 6 minutes have elapsed, the EXV is then controlled according to suction superheat, discharge
temperature and compressor speed.
ƒ
When the outdoor unit is in standby:
y
The EXV is at position 304 (steps).
ƒ
When the outdoor unit stops:
y
The EXV first closes fully, then moves to the standby position (304 (steps)).
4.6 Outdoor Fan Control
The speed of the outdoor unit fan(s) is adjusted in steps, as shown in Table 3-5.3.
Table 3-5.3: Outdoor fan speed steps
Fan speed index
Fan speed (rpm)
4kW 6kW 8kW
10-16kW (1Ph) 12-16kW (3Ph)
Upper fan
1
Lower fan
2
Upper fan
1
Lower fan
2
0 0 0 0 0 0 0 0
1 300 300 300 300 - 300 -
2 340 340 340 330 300 330 300
3 400 400 400 400 380 400 380
4 450 450 450 460 440 460 440
5 520 520 520 520 500 520 500
6 600 600 600 630 610 630 610
7 680 680 680 780 760 780 760
8 730 730 730 - - - -
9 800 800 800 - - - -
Notes:
1. The upper fan is labelled FAN_UP in the wiring diagram. Refer to the M-Thermal Split Engineering Data Book
Part 2, 4 “Wiring diagram”.
2. The lower fan is labelled FAN_DOWN in the wiring diagram. Refer to the M-Thermal Split Engineering Data Book
Part 2, 4 “Wiring diagram”.
MUNDOCLIMA AEROTHERM V17 - BIBLOC