Sauter flexotron®800
ventilation
Functional description
P100012082
34
5.1.2
Heater types
Water heating
Control
When the unit is in running mode the heating valve is controlled by the analogue output
’’Y1 Heating’’ or by two digital outputs ‘‘Heating 3-pos. actuator, increase’’ and ‘‘Heating,
3-pos. actuator, decrease
’’.
Frost protection
The heater return water temperature is measured using the analogue input
’’Frost
protection sensor
’’. Low temperatures will generate an internal, proportional signal that
is used to force the heating valve open thereby preventing freeze-up of the heater.
The internal signal (
‘‘Internal signal’’) will begin to rise as the frost protection
temperature falls below
‘‘Alarm level’’ + ‘‘Prop. Band’’ in order to reach 100 % output
when the signal has fallen to
‘‘Alarm level’’.
When
’’Internal signal’’ reaches 100 % or the digital input ’’Frost protection’’ is activated,
the unit is shut down, the heating output is set to completely open mode and an alarm
is activated. The unit is restarted when the alarm has been acknowledged and the
temperature for the frost protection sensor has risen above
‘‘Alarm level’’ + ‘‘Prop.
Band
’’.
The frost protection alarm level is set in the menu
Settings/Alarm settings/Alarm limit.
Shutdown mode
If frost protection is activated the controller will go into
’’Shutdown mode’’ when the
running mode switches to
’’Off’’. The shutdown controller will control the heating output
to maintain a constant settable temperature at the frost protection sensor.
“Frost protection sensor”
“Internal signal”
0 %
100 %
Prop.band
Alarm level
