Zehnder EASY 5.0
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When the measured air pressure is lower than the setpoint, the controller increases the value (0-10V voltage) of the fan
speed setpoint signal to increase the air volume and thus the resulting pressure, and vice versa.
It should be noted that as the network has a variable air volume, the thermal power delivered by any heating and/or
cooling coils is variable, whether they are integrated into the ventilation unit or not.
A curved air duct placed directly at the inlet or outlet of the machine can interfere with pressure and operational
instability. A distance of at least 5 times the diameter of the air duct must be maintained between the curved air duct
and the machine.
The pressure settings for reduced and normal operation are identical ex factory as VAV air systems generally operate on
a single pressure level. However, it is possible to set a normal operation pressure setpoint that is different (higher) than
the reduced operation pressure setpoint, in order to potentially manage 2 different pressure levels or to further increase
the resulting air volume when night cooling is activated. In the latter case, it must be ensured that the reduced operation
remains active for the entire duration of the night cooling period (00:00 - 07:00).
19.5. MAC2 controller
The MAC2 controller is a closed-loop constant air volume (CAV) controller.
The speed of the supply and return air fans is adjusted individually and continuously by means of a PID algorithm in
order to obtain a volume equivalent to the volume setpoint set in the controller, regardless of the extent to which the air
filters are clogged.
When the measured air volume is lower than the setpoint, the controller increases the value (0-10V voltage) of the fan
speed setpoint signal to increase the resultant air volume, and vice versa.
Z-MASTER-V1122-CSY-INM-Zehnder Easy5.0
Volume flow
Constant volume
flow HS
Pa
Return air
Fresh air (outdoor)
Exhaust air
Supply air
VAS
VAR
Supply volume setpoint
Return volume setpoint
Air flow value reflection
Air flow value reflection
Setpoint speed
Setpoint speed
+
+
-
-
PID
PID
TRPS
TRPR
