4.3 Free cooling
This function is used during the warm period to save energy by using cold outdoor air, e.g. during night
time, to cool down the building.
Note:
The following is only valid if the free cooling function is set to Active in the program menu.
In order for the free cooling function to work, a total of 3 temperature sensors (outdoor, supply and
extract/room) are required.
Free cooling is only activated when the following starting conditions are met.
Starting conditions:
• Less than 4 days have passed since the unit was last in running mode
• The outdoor temperature during the previous running period exceeded a set limit (+22°C)
• It is between 00:00 and 07:00:00 in the day (settable)
• The timer outputs for normal speed, Extended running normal and External stop are Off
• A time channel will be On sometime during the recently started 24 hours.
The unit checks the night temperature (indoor and outdoor temperature) during 3 minutes at the set
starting hour when the fans are started so that the sensors can perform a temperature measurement.
If above conditions are met the free cooling function is started, if not the unit goes back to OFF position.
If the outdoor sensor is not located in the outdoor air inlet duct and a room sensor has been selected,
the unit will not start free cooling as long as all the temperatures are not within the start and stop
temperature intervals.
Stop conditions:
• Outdoor temp above the set max value (+18°C) or below the set min value (condensation risk, +10°C)
• The room temp/extract air temp is below the set stop value (+18°C)
• One of the timer outputs for normal speed, External stop or Extended running normal is On
• The time has past 07:00:00.
When free cooling is active, the fans run at normal speed or the set value for pressure/flow control and the
digital output Free cooling is active. The outputs Y1-Heating, Y2-Heat exchanger and Y3-Cooling are shut
down. After free cooling has been activated, the heating output is blocked for 60 minutes (configurable).
5 Interface Description
5.1 Control Panel
The SCP control panel is delivered with a 10 m cable (up to 100 m can be used) that is connected to
the panel and with a fast coupling contact, connected to the Topvex unit. The contact is connected to
the
Corrigo
controller in the electrical connection box. The cable can be unscrewed in the back of the
control panel (figure 5).
Operation and Maintenance Instructions
132616
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Systemair Sverige AB
