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11
Pump operation
With no room thermostat connected to the unit (1), the circulation pump (1.8) and (11) will operate as long as the unit is on for space heating.
The pump (1.8) will operate as long as the unit is on for heating domestic hot water.
Space heating and cooling
According to the season, the customer selects cooling or heating through the user interface. The unit (1) will operate in cooling mode or heating
mode to achieve the target water flow temperature. In heating mode, the 2-way valve (20) is open. Hot water is provided to both the fan coil units
and the floor heating loops. In cooling mode, the motorized 2-way valve (20) is closed to prevent cold water running through the floor heating loops
(FHL).
The ON/OFF setting of the heating/cooling operation is done by the user interface.
NOTE
Details on pump configuration can be found in
10.5 setting the pump speed
.
NOTE
CAUTION
When closing several loops in the system by remotely controlled valves, it might be required to install a bypass valve (18) to avoid the
flow switch safety device from being activated. See also
8.2 Application 2
.
Wiring of the 2-way valve (20) is different for a NC (normal closed) valve and a NO (normal open) valve. The NO valve is unavailable
to this unit. Make sure to connect to the correct terminal numbers as detailed on the wiring diagram.
8.5 Application 5
Space heating with an auxiliary boiler (alternating operation).
Space heating application by either the unit or by an auxiliary boiler connected in the system.
■ The unit controlled contact (also called 'permission signal for the auxiliary boiler") is determined by the outdoor temperature (thermistor
located at the outdoor unit). See
10.7 Field settings/OTHER HEATING SOURCE
■ Bivalent operation is possible for both space heating operation and domestic water heating operation.
■ If the auxiliary boiler only provides heat for space heating, the boiler must be integrated in the piping work and in the field wiring according to
the illustration for
application a
.
■ If the auxiliary boiler is also providing heat for domestic hot water, the boiler can be integrated in the piping work and in the field wiring
according to the illustration for
application b
.
■
Application c
can be used If the temperature of water from the outdoor unit is not high enough. An additional 3-way valve should be
installed, if ambient temperature is high and thus water from outdoor unit is high enough, The boiler will not work and water will not flow past
the boiler. When ambient temperature is low and and thus water from outdoor unit is not high enough, the boiler will work and the 3-way valve
will open to make water from outdoor unit flow past the boiler and be heated again.
CAUTION
Be sure that the boiler and the integration of the boiler in the system is in accordance with relevant local laws and regulations.
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 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.
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