Sauter flexotron®800
ventilation
Functional description
P100012082
43
Alarm
An alarm is activated if the efficiency falls below the set alarm level (50 %).
In- and outputs
AI
Outdoor temperature sensor
AI
Extract air sensor
AI
Exhaust air sensor
5.1.10
External setpoint
An external setpoint device can be connected. The setpoint device must follow the
Ni1000 resistance curve, for example the EGT388F002. The unit is connected to the
analogue input signal
’’Extra temperature sensor 1’’. The function must be activated in
the menu
’’Configuration/External setpoint’’. The setting range can be min/max limited
via a setting in the controller. The factory setting is min: +12, max: +30.
In- and outputs
AI
Extra temperature sensor 1
5.1.11
Recirculation
Recirculation is a function for distributing the air in the room using the supply air fan.
The function can be used even when there is no heating or cooling demand. When
using recirculation control, the extract air fan stops and a recirculation damper opens
which allows the air to circulate through the unit.
Recirculation is activated either via a digital input signal or by connecting it to "Timer
output 5". If timer output for normal/reduced speed is activated during recirculation via
’’Timer output 5’’, normal/reduced speed gets priority. If timer output for normal/reduced
speed is activated during recirculation via a digital input, recirculation gets priority.
Recirculation control can be configured as either air circulation (temperature control
inactive) or air circulation with temperature control. (Only heating, only cooling or both
heating and cooling). Recirculation control has its own setpoint. However, the other
settings are the same as for normal operation, i. e. if normal operation has been
configured as room control, room control will also be used during recirculation.
The recirculation setpoint can be configured as constant or offset. Constant means that
the recirculation setpoint will be used. Offset is based on an offset from the supply air
setpoint.
To lower the temperature, it is possible to configure free cooling to be used during
recirculation, if the conditions for free cooling are fulfilled. Then, the recirculation
damper closes, the supply and extract air dampers open and the extract air fan starts
(the supply air fan also starts, if it is not already running). If the free cooling function is
not configured for recirculation control and you want to cool down the supply air via a
low recirculation setpoint, the cooling battery will be used. A max. room temperature
can be configured for recirculation control. If the room temperature rises above the set
value (FS 25°C), recirculation will be stopped. When the room temperature has fallen 1
K below the set max limit, recirculation will start again if the start conditions are still
fulfilled.
When running frequency controlled fans and using recirculation control you can,
depending on the type of fan control, configure a special pressure/flow offset for the
setpoint or a manual output signal for the supply air fan.
5.1.12
Change-over
Change-over is a function for installations with 2-pipe systems. It makes it possible to
use the same pipe for both heating and cooling, depending on whether heating or
cooling is required.
