Corrigo ventilation 3.4 manu

32 Chapter 5 Functional description Manual Corrigo Ventilation, revision R
Frost protection
The heater return water temperature is measured using the analogue input ”Frost prot.temp”. 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 ”Deicing heat exchanger” 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 limit frost” + “P-Band”.
Frost protection control is available on Y1 heating, Y4 extra sequence or on both Y1 and Y4.
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.
5.1.2.2 Electric heating
Control
The heating is controlled using the analogue output ”Y1 heating”. On activation of the digital input
“High temp limit switch” the unit will be shut down, either according to the stop sequence described
in section Start/stop of unit or as an emergency shutdown. The unit will restart after the alarm has
been acknowledged and “High temp limit switch” has reset. Note that activation of the input signal
“Flow switch” will also stop the unit.
Relay el.
heating
Control voltage
Contr.
voltage
High limit
thermostat
Auxiliary
relay
Corrigo
Wiring suggestion high temp limit when using electric heating.
“Frost protection sensor”
“Internal signal”
0 %
100 %
Prop.band
Alarm level