Parameters
WE
Range of values
K
P
Humidifier
0.5
0.1 to 99.9
T
N
Humidifier
60 sec 1 to 999 sec
T
V
Humidifier
– – –
– – – to 999 sec
5.6
Fans with variable speed
The analog output AA can be used to control the speed of the fans and the air volume based
on the air quality. If the air quality falls below the parameter
Air quality set point, the air vol-
ume is increased based on the
Minimum air volume flow.
When an exhaust air cascade control or a room temperature cascade control is used, the
controller can be programmed so that the air volume is increased when the supply air tem-
perature limit is reached to eliminate the system deviation as quickly as possible. This func-
tion has priority over the air quality control. After the system deviation has been balanced
out, the air quality control is enabled again. The function is activated when the
Factor of
change K
P
is selected greater than 0.
Example:
The supply air temperature has reached its minimum permissible value at 50 % air volume
(y
AA
= 50 %).
4
Exhaust air temperature set point = 22 °C
4
Exhaust air temperature
= 24 °C
4
Factor of change K
P
= 5
4
Y
Y
XD K
AA
P
neu
= +
⋅
(
)
=
+
° −
°
÷
° ⋅
⋅
50
24
22
40
100
5
%
%
C
C
C
=
75%
(XD is the percentage error in relation to the measuring range. Its maximum limit is 10 %)
.
EB 5477 EN
51
Control methods and system components
Fig. 20 · Output signals, e.g. in system code number 6 (humidifier only)
Control
signal
Controlled variable