The master loop has a P control response with adjustable
Exhaust air humidity set point or
Room humidity set point and Kp Humidity master loop. The supply air control is implemented
by a PID control algorithm with adjustable
Humidity set point of the slave loop. The humidity
control loop can be used either just for humidifying or for humidifying and dehumidifying by
involving the cooling coil in sequence to the humidifier. The requirements of the humidity
control loop for dehumidifying and the temperature control loop for cooling are converted
internally into one common control signal Y3 for the cooling unit. Each output can be adap-
ted to the dynamics of the corresponding system components by means of the
K
P
, T
N
and
T
V
control parameters that are adjustable. The set point of the supply air humidity control loop
is shifted depending on the system deviation in the exhaust air or room humidity control
loop:
Each deviation in humidity by the amount x shifts the supply air humidity set point by the
amount x multiplied by the parameter
K
P
Humidity master loop within the range Supply air
humidity minimum limit and Supply air humidity maximum limit.
4
x = Exhaust air humidity set point – Exhaust air humidity actual value
4
Humidity set point of the slave loop
calculated
=
Humidity set point of the master loop + x · K
P
Temperature of the master loop
Note!
If the calculated set point is not within the limit, the minimum or maximum limit applies as
the new set point.
Functions
WE
Configuration
Control method
Exhaust air/room cascade control (–> page 17)
Sensor F6, supply air humidity
or
assignment of inputs AE1 to AE4
OFF
Fb6 = ON oder
Fb18 = ON,
option:
AE2F6
Sensor F7, exhaust air or room humidiy
or
assignment of inputs AE1 to AE4
OFF
Fb7 = ON oder
Fb18 = ON,
option:
AE4F7
Parameters
WE
Range of values
Exhaust air humidity set point
or
room humidity set point
50 %rH
50 %rH
0 to 100 %rH
0 to 100 %r
Humidity set point of the slave loop
50 %rH 0 to 100 %rH
K
P
Humidity master loop
1.0
0.1 to 99.9
Supply air humidity minimum limit
40 %rH 0 %rF up to supply air humidity maximum limit
Supply air humidity maximum limit
60 %rH Supply air humidity min. limit up to 100 %rH
K
P
0.5
0.1 to 99.9
T
N
60 sec
1 to 999 sec
T
V
– – –
– – – to 999 sec
EB 5477 EN
43
Control methods and system components