7.5Condensate accumulation control
Activate the Limitation of the system deviation for OPEN signal function to start up condensate accumulation plants, in particular to avoid problematic excess temperatures. The controller re- sponse to set point deviations which cause the primary valve to open is attenuated. The control- ler response to set point deviations which cause the control valve to close remains unaffected.
Function | WE | Configuration |
Limitation of the system deviation for | OFF | FB11/FB12 = ON |
OPEN signal RK1/RK2 | 2 °C | Maximum system deviation / 2 to 10 °C |
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Note!
The condensate accumulation control function can only be activated when no on/off control has been configured, i.e. when FB10 = ON or FB17 = ON.
7.6Three-step control
The flow temperature can be controlled using a PI algorithm. The valve reacts to pulses that the controller emits when a system deviation occurs. The length of the first pulse, in particular, de- pends on the extent of the system deviation and the selected Proportional 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 in- fluenced by the Reset time TN (the pause length increases as TN increases).
The Transit time TY specifies the time required by the valve to travel through the range of 0 to 100 %.
Functions | WE | Configuration |
ON | FB10 = ON | |
| 0.5 | KP (proportional gain) / 0.1 to 50 |
| 200 s | TN (reset time) / 1 to 999 s |
| 90 s | TY (valve transit time) / 15 to 240 s |
| 2 x TY | Pump lag time / 1 x TY to 10 x TY |
ON | FB17 = ON | |
| 0.5 | KP (proportional gain) / 0.1 to 50 |
| 60 s* | TN (reset time) / 1 to 999 s |
| 30 s* | TY (valve transit time) / 15 to 240 s |
* WE applies to systems Anl 5, 6; TN = 200 s, TY = 90 s applies for system Anl 4
EB 5476 EN 59
