M thermal Split
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Table 3-6.4: Component control during force cool operation 
Component
Wiring diagram 
label 
4-16kW 
Control functions and states
Inverter compressor   
COMP 
 
Runs at force cooling operation rotation speed
DC fan motor  FAN 
 
Runs at force cooling operation speed 
Electronic expansion valve    EXV 
 
304 (steps) 
Four-way valve  4-WAY 
 
Off 
6.4 Fast DHW Operation 
Fast DHW operation is used to quickly meet a requirement for domestic hot water when DHW priority has been set on the 
user interface.   
Domestic hot water demand priority can be ended by changing the switch on controller from "on" to "off". 
Table 3-6.5: Component control during fast DHW operation 
Component 
Wiring 
diagram label 
4/6kW  8/10/12/14/16kW
Control functions and states 
Inverter compressor   
COMP 
   
Controlled according to load requirement
DC fan motor    FAN 
   
Controlled  according  to  outdoor  heat  exchanger 
pipe temperature 
Electronic expansion valve    EXV 
   
Position  (steps) from  0  (fully  closed)  to  480  (fully 
open), controlled according to discharge superheat
Four-way valve  ST 
   
On 
Tank electric heater  TBH 
   
On 
6.5 Two zones control
1
 
Two zones control function is used to control temperature of each zone separately, thus different type radiator will operate 
at its optimal temperature and water pump cycle time will be reduced to save energy.   
 
  Cooling mode 
In two zones control for cooling mode, when the setting temperature of a certain zones is reached, the zone and water 
pump of this zone will turn off. 
  Heating mode 
In two zones control for heating mode, the on/off control of zone and water pump is same with cooling mode, but in 
addition, the mixing valve (3-way valve SV3) control function will be activated to adjust the water temperature of the low 
temperature zone by control the opening time and closing time of the valve. The mixing valve will only turn on when two 
zones control for heating is activated. On other conditions, the mixing valve will keep off. When the valve initially turns on, 
the opening time and closing time is same and then the time is controlled according to the difference between water pipe 
temperature and setting water temperature of the controlling zone.   
  Hydraulic adapter PCB (Optional) 
With the help of hydraulic adapter PCB, totally 8 thermostats can be used at the same time for maximum 8 rooms to 
control heat pump. 
Note: 
1. M thermal units just have the controlling function, while the mixing valve, water pump of each zone need to be field 
supplied and connect to M thermal unit. 
 
Midea CAC