• Monobloc • EDLQ011-016AA6V3
1
3
• Altherma • Monobloc
8
3
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EDLQ011-016AA6V3
3TW57759-4A
Bivalent system
Space heating with an auxiliary boiler (alternating operation)
Space heating application by either the altherma indoor unit or by an auxiliary boiler
connected in the system. An auxiliary contact decides whether either the EKHB* indoor unit
or the boiler will operate. This auxiliary contact can e.g. be an outdoor temperature
thermostat, an electricity tariff contact, a manually operated contact, etc.
Sanitary warm water in such an application is always provided by the sanitary water tank
which is connected to the indoor unit, including when the boiler is in operation for space
heating.
The auxiliary boiler can be integrated in the pipework and in the field wiring according to
the illustrations below.
1 Outdoor unit
2 Indoor unit
3 Heat exchanger
4 Pump
5 Shut-off valve
6 Collector (field supply)
7 Shut-off valve
8 Motorised 3-way valve (field supply)
10 Booster heater
11 Heat exchanger coil
12 Sanitary water tank
15 Boiler (field supply)
16 Aquastat valve (field supply)
17 Shut-off valve (field supply)
18 Non-return valve (field supply)
FHL 1...3 Floor heating loop (field supply)
Field wiring
Boiler thermostat
Boiler thermostat
Boiler thermostat
C
Auxiliary contact (normal closed)
th
Heating only room thermostat
K1A
Auxiliary relay for activation of EKHB* unit (field supply)
K2A
Auxiliary relay for activation of boiler (field supply)
Operation
When the room thermostat (th) closes, either the EKHB* unit or the boiler starts operating,
depending on the position of the auxiliary contact ( C )
Make sure that auxiliary contact ( C ) has sufficient differential or time delay so
as to avoid frequent changeover bethween the EKHB* unit and the boiler. If
the auxiliary contact ( C) is an outdoor temperature thermostat, make sure to
install the thermostat in the shade, so that it is not influenced or turned
ON/OFF by the sun.
Frequent switching may cause corrosion of the boiler in an early stage. Contact
the manufacturer of the boiler.
During heating operation of the EKHB* unit, the Altherma unit will operate so
as to achieve the target leaving water temperature as set on the user interface.
When weather dependent operation is active, the water temperature is
determined automatically depending on the outdoor temperature.
During heating operation of the boiler, the boiler will operate so as to achieve
the target leaving water temperature as set on the boiler controller.
Never set the target leaving water temperature setpoint on the boiler controller
above 55°C.
Make sure to only have 1 expansion vessel in the water circuit. An expansion
vessel is already premounted in the Altherma unit.
Make sure to configure the DIP switch SS2-3 on the PCB of the EKHB* switch
box correctly. Refer to ’ Room thermostat installation configuration’ in the
installation manual supplied with the unit.
Make sure that return water to the EKHB* heat exchanger never exceeds 55°C.
For this reason, never put the target leaving water temperature setpoint on the
boiler controller above 55°C and it required, install an aquastat(*) valve in the
return water flow of the EKHB* unit.
Daikin shall not be held liable fo any damage resulting from failure to observe
this rule.
(*)The aquastat valve must be set for 55°C and must operate to close the return water flow to the EKHB*
unit when the measured temperature exceeds 55°C. When temperature drops to a lower level, the
aquastat valve must operate to open the return water flow to the EKHB* unit again.
