M thermal Mono
20 202004
Midea M thermal Mono Service Manual
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.
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).
At power-on:
The EXV first closes fully, then moves to the standby position. After a few seconds the EXV moves to an initial
running position, which is determined according to operating mode and outdoor ambient temperature. After a
further a few minutes, the EXV is controlled according to suction superheat and discharge temperature. Once a
further a few minutes have elapsed, the EXV is then controlled according to suction superheat, discharge
temperature and compressor speed.
When the outdoor unit is in standby:
The EXV is at standby position.
When the outdoor unit stops:
The EXV first closes fully, then moves to the standby position.
4.6 Outdoor Fan Control
The speed of the outdoor unit fan(s) is adjusted in steps, as shown in Table 3-4.3.
Table 3-4.3: Outdoor fan speed steps
To Next Page
Loading...
Need help?
General
