Sauter flexotron®800
ventilation
Functional description
P100012082
37
Outdoor temp control of exchanger
Instead of using Y2 for analogue control of the heat exchanger it can be set to run on-
off against outdoor temperature. The function controls a digital output
‘‘Exch control’’,
which is activated when the outdoor temperature falls below a set value.
Mixing dampers
Control
The analogue output signal
’’Exchanger Y2’’, or the two digital output signals
"Exchanger 3-position, increase" and "Exchanger 3-position, decrease", control two
dampers for gradual mixing of outdoor air and recirculated air. In this mode the output
signal decreases with increasing heat demand.
CO
2
If demand controlled ventilation (see 5.4.2) is activated in combination with mixing
dampers, and the CO
2
-value rises above the setpoint value, the dampers will let in more
outdoor air. The function is controlled by a PI-controller. Factory settings: P-band
100ppm and I-time 100 seconds. These values can only be changed in CASE
flexotron®.
Minimum limit
An outdoor air minimum limit for can be set using the front panel. The limit value is
settable between 0 and 100 %.
In- and outputs
Plate
Rotating
Exch
Liquid
Dampers
AI
AI
AI
AI
Outdoor temp. sensor (optional, outd.
temp start)
DO
DO
DO
DO
Activate exchanger (optional, outd.
temp start)
AI
AI
De-icing sensor (optional)
DI
DI
De-icing signal (optional)
DI
Rotation sentinel (optional)
Start delay exchanger
This function delays the exchanger start at start-up of the unit.
100 % exchanger output at start-up
After the delay described above, the exchanger output will be 100 % during the set
time.
5.1.4
Types of chillers
Step controller Heating / DX cooling
As alternative or complement to the above mentioned analogue control, heating and
cooling can be activated in steps. The internal signal is then used to activate digital
outputs for control of the heaters/chillers. Up to four heater outputs and three cooler
outputs can be configured. There are two possible modes:
Sequential
Each output step has individually settable on and off values in percent of the control
signal. The number of steps is equal to the number of heater/chiller groups. Minimum
