90
EB 5573 EN
System-wide functions
8.5
Condensate accumulation control
Activate the
limitation of set point deviation for OPEN signal
function to start up condensate
accumulation plants, in particular to avoid problematic excess temperatures. The controller
response to set point deviations which cause the primary valve to open is attenuated. The
controller response to set point deviations which cause the control valve to close remains un-
affected.
The
condensate accumulation control
function can only be activated when the control circuit
concerned is controlled using a PI algorithm (three-step control).
Functions
WE
Configuration
Control mode
1
CO1, 2, 4 > F12 - 1
Limitation of set point deviation for OPEN
signal
0
3.0 °C
CO1, 2, 4 > F13 - 1
Max. system deviation: 3.0 to 10.0 °C
8.6 Three-step control
The flow temperature can be controlled using a PI algorithm. The valve reacts to pulses that
the controller sends when a system deviation occurs. The length of the first pulse, in particu-
lar, depends on the extent of the system deviation and the selected 'Gain KP' (the pulse
length increases as KP increases). The pulse and pause lengths change continuously until the
system deviation has been eliminated. The pause length between the single pulses is greatly
influenced by the 'Reset time Tn' (the pause length increases as Tn increases). The 'Valve
transit time TY' specifies the time required by the valve to travel through the range of 0 to
100 %.
Functions
WE
Configuration
Control mode
1
2.0
120 s
0 s
35 s
CO1, 2, 4 > F12 - 1, HC_
KP (gain): 0.1 to 50.0
Tn (reset time): 1 to 999 s
TV (derivative-action time):
do not change the
value.
TY (valve transit time): 15, … , 240 s
Note
