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Siemens
Central apartment unit QAX910
CE1N2707en
Building Technologies
06.01.2009
The Economy room temperature setpoint is increased as a function of the compos-
ite outside temperature. Changeover is adjustable and helps prevent load peaks
when changing from Economy to Precomfort or Comfort for instance.
The minimum flow temperature setpoint is raised as a function of the composite
outside temperature, thus ensuring a minimum flow temperature for uncontrolled
rooms.
The central apartment unit triggers summer operation. Changeover can be accom-
plished as follows:
Manually, date-related, according to the attenuated outside temperature, via a digi-
tal input, or through active changeover to cooling mode.
The heating circuit valves connected to an RRV912 / RRV918 heating circuit con-
troller have the position 0% or 100% and the SSA955 radiator control actuators will
be driven to the preselected valve positions.
The QAX910 provides DHW control with the help of a specific DHW time switch.
DHW heating is either enabled or disabled based on the temperature acquired by
the DHW temperature sensor connected to the QAX910 or an RRV912 / RRV918 /
RRV934.
The signal for DHW charging or changeover is delivered either via the internal re-
lay output or the relay output of an RRV912 / RRV918 heating circuit controller or
RRV934 multi-controller. DHW charging can take place via diverting valve / charg-
ing pump and / or an electric immersion heater.
Specific functions for ventilation equipment and air conditioners
The QAX910 controls ventilation plant with a maximum of 3 stages via an RRV934
multi-controller. The ventilation stages can be controlled either manually, via a 7-
day program, indoor air quality sensor or humidity sensor. Ventilation can be influ-
enced by absence, the holiday function or an open window.
The following operation and control functions are available:
−
The apartment timer activates apartment operating mode Comfort for an adjustable
period of time
−
Forced ventilation activates the highest ventilation stage for a predefined period of
time
−
In summer operation, cooler outside air passes through the HR bypass during the
periods of time night cooling is active
−
Counting the number of operating hours for delivering a service message
−
Release of kitchen exhaust hood via an open window to ensure sufficient amounts of
air are made available
−
Display of active fireplace ventilation mode (external plant)
Each room can be assigned one cooling release contact for switching an air condi-
tioner (e.g. split unit).
Release can take place via the local relay contact of the central apartment unit, the
relay contacts of the RRV912 / RRV918 heating circuit controllers, the RRV934
multi-controller, the RF adapter plug KRF960-x, or via S-Mode.
By integrating the ZENNiO interface (S-Mode TP1), operating mode, setpoint and
release of the air conditioner (e.g. split unit) per room can be controlled via the
central apartment unit. Heating and cooling mode of the air conditioner can be
supported.
The air conditioner ensures autonomous room temperature control.
Outside temperature-
dependent night set-
back
Minimum flow
temperature setpoint
Summer operation
DHW charging /
DHW control
Ventilation
Release contact
for cooling
Air conditioner via
ZENNiO module
