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AB Industrietechnik srl – Via Julius Durst, 70 – 39042 BRESSANONE (BZ) Italy – Tel: +39 0472/830626 – [email protected] – www.industrietechnik.it
Control of speed based on CO
2
(
009
=1):
In some situations in which rooms are crowded, it is necessary to regulate the air quality to ensure the air is renewed when
the CO
2
concentration exceeds a given threshold.
To control the speed of the fan based on the CO
2
, set the parameter
009
to 1.
Configure
023
=5 and position jumper JP1 in position “3-2”; the input sensor AI3 is automatically configured as input 0..10 V
for air quality; the corresponding scale is set at 0..2000 ppm (
206
=0 and
207
=2000) with the unit of measurement (
208
=0).
Then define the parameters of the PI controller for reduction of CO
2
(
167
: setpoint
168
: proportional band and
169
: integral
time).
Depending on the type of fan, they will work according to the following chart:
CO2
167
OFF
Fan 1
on/off speed
CO2
167
168
0
Modulating
fan
ON
CO2
167
168
OFF
Fan 2
on/off speed
FAN1
FAN2
CO2
167
168
OFF
Fan 3
on/off speed
FAN1
FAN3
FAN2
FAN1
FAN3
167
air exchange setpoint
168
air exchange proportional band
VEL1: speed 1= [
(
154
/ 100) x (
151
-
150
)
] +
150
for the supply and =[(
154
/ 100) x (
153
-
152
)] +
152
for the extraction.
VEL2: speed 2= [(
155
/ 100) x (
151
-
150
)] +
150
for the supply and =[(
155
/ 100) x (
153
-
152
)] +
152
for the extraction.
VEL3: speed 3= [(
156
/ 100) x (
151
-
150
)] +
150
for the supply and =[(
156
/ 100) x (
153
-
152
)] +
152
for the extraction.
For the two-speed fan:
if CO
2
<=
167,
speed 1 is ON, and if CO
2
increases when CO
2
> (
167
+
168
), speed 2 is ON,
if CO
2
decreases and CO
2
<= (
167
+
168
/2), speed 1 is ON,
For the three-speed fan:
if CO
2
<=
167,
speed 1 is ON,
if CO
2
increases and CO
2
>= (
167
+ (
168
*(2/3))) and CO
2
< (
167
+
168
), speed 2 is ON,
if CO
2
> (
167
+
168
), speed 3 is ON,
if CO
2
decreases and CO
2
<= (
167
+ (
168
*(2/3))) and CO
2
> (
167
+ (
168
*(1/3))), speed 2 is ON,
