Corrigo ventilation 3.4 manu

44 Chapter 5 Functional description Manual Corrigo Ventilation, revision R
The extract air fan and the supply air fan have individual start and stop delays which are normally
set so that the extract air fan is started before the supply air fan. If there are not enough digital
outputs for individual control, both fans will have to be started using the signal for the supply air
fan, and the delay be created using an external time relay.
5.4.1 Pressure control
Frequency control pressure
During pressure control, two separate analogue output signals are used for supply and extract air
and two separate analogue input signals for supply and extract air for pressure transmitters. The fan
speeds are controlled via frequency converters, thereby maintaining constant pressure. The pressure
transmitter inputs are scalable using “Min volt input (Vmin)” and “Max volt input (Vmax)”.
A digital activation signal is normally used for each fan ("SAF Freq Start " and " EAF Freq Start "),
for sending a start signal to the frequency converters. The start signal is activated as long as the fan
is expected to be running.
For the supply and extract air fans, there are two individually settable setpoint values, one
corresponding to normal speed and one corresponding to reduced speed. Changing between the two
setpoint values is done using the timer channels for normal and reduced speed or using digital input
signals ("Extended Operation, Normal" and "Extended Operation, Reduced").
Outdoor compensation
When running pressure control, it is also possible to outdoor compensate the pressure setpoint
value.
The outdoor compensation is linear and is set using two parameter pairs which give the value of the
compensation at two different outdoor temperatures. The compensation can be positive or negative.
The outdoor compensation is set in the menu Actual/Setpoint.
Using E tool
©
, you can also choose to only outdoor compensate the pressure value of the supply air
fan. In that case, the extract air fan is controlled with constant flow, independent of the outdoor
temperature.
The compensation can be selected to apply to both normal and reduced speed, or for normal speed
only (factory setting = both speeds).
Extra compensation curve
As a complement to the above outdoor compensation, there is a function called ”Extra
compensation curve pressure/flow setpoint” which can be used to set a compensation based on the
room, extract air, supply air or outdoor temperature. The curve has three parameter pairs which
correspond to the value of the compensation at three different temperatures.
Controller output-dependent extra compensation curve
The compensation is made using the control curve, one for heating demand and one for cooling
demand. It is possible to select whether the compensation (0...10000) should increase or decrease
the pressure setpoint. The 0...10000 compensation follows the current control quantity for the fans.