Midea HB-A100/CGN8-B, Service Manual

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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.
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