Midea MHC-V10W/D2N1, Installation & Owner'S Manual, Page: 17 / 96

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When the room temperature of both zones is above the thermostat set point, the outdoor unit and pump will stop operating.
The advantage of the dual set point control is that the heat pump will/can operate at the lowest required water flow temperature when only
floor heating is required. Higher water flow temperatures are only required in case fan coil units are operating. This results in better heat pump
performance.
Pump operation and space heating
The pump (1.8) and (11 will operate when there is a request for heating from A and/or B. The outdoor unit will start operating to achieve the
target water flow temperature. The target water leaving temperature depends on which room thermostat is requesting heating.
NOTE
1 outdoor unit
1.1 manometer
1.2 pressure relif valve
1.3 expansion vessel
1.4 plate heat exchanger
1.5 backup heater
1.6 air purge valve
1.7 flow switch
1.8 P_i: circulation pump in the unit
2 y-shape filter
3 stop valve (field supply)
4 user interface
6 drain valve (field supply)
7 fill valve (field supply)
8 buffer tank (field supply)
9 balance tank (field supply)
9.1 air purge valve
9.2 drain valve
10 expansion vessel (field supply)
11 P_o: outside circulation pump (field supply)
12 collector (field supply)
18 bypass valve (field supply)
20 SV2:2-way valve (field supply)
24 mixing station (field supply)
24.1 P_c: mixing pump
FHL 1...n floor heating loop
FCU 1...n fan coil units
M1...n motorized valve (field supply)
T1…n room thermostat (field supply)
NOTE
If the volume of balance tank(9) is larger than 30L, the buffer tank(8) is unnecessary, otherwise the buffer tank(8) should be installed and the
total volume of balance tank and buffer tank should larger than 30L.The drain valve (6) should be installed at the lowest positon of the system.
For the 5/7/9kW unit, the backup heater (1.5) is not integrated in the outdoor unit. An independent backup heater can be selected and installed
in the door.
■ Make sure to correctly configure the room thermostat installation on the user interface. Refer to "10.7 Field settings/ROOM
THERMOSTAT" .
■ It is the installers’ responsibility to ensure that no unwanted situations can occur (e.g. extremely high temperature water going towards floor
heating loops, etc.)
■ The supplier does not offer any type of mixing station. Dual set point control only provides the possibility to use two set points.
■ When only zone A requests heating, zone B will be fed with water at a temperature equal to the first set point. This can lead to unwanted
heating in zone B.
■ When only zone B requests heating, the mixing station will be fed with water at a temperature equal to the second set point.Depending on
the control of the mixing station, the floor heating loop can still receive water at a temperature equal to the set point of the mixing station.
■ Be aware that the actual water temperature through the floor heating loops depends on the control and setting of the mixing station.