Table of Contents
Advertisement
Valve outputs | Valve output - General
The continuous flow of water through the valve, and thus the continuous heating of
the drives causes variations and changes to the dead times of the drives during the
opening and closing phase. The short cycle time and the dead times means that the
required command value (mean value) is only set with a possibly large deviation. For
the room temperature to be regulated constantly after a set time, the controller must
continually adjust the command value to compensate for the mean value shift caused
by the short cycle time. Usually, the control algorithm implemented in the controller
(PI control) ensures that control deviations are compensated.
9.4.4 Valve direction of action
The heating actuator possesses 6 electronic outputs, each of which can silently activ-
ate up to 4 (AC 230 V) or 2 (AC 24 V) actuators. Both deenergised closed and deen-
ergised opened actuators can be connected. The parameter "In voltage-free state
(direction of action)" on the parameter pages "VOx - General" specifies which drive
type is connected to a valve output.
Only actuators with the same characteristics may be connected to each valve
output (deenergised closed/opened). The drive type must match the configura-
tion.
The configured valve direction of action is taken into account in each valve activation.
With 1-byte command values and deenergised closed valves, the switch-on time is
derived directly from the configured PWM and the cycle time.
Example: PWM = 30%, cycle time = 10 minutes -> Switch-on time = 3 minutes,
switch-off time = 7 minutes.
In the case of 1-byte command values and deenergised opened valves, the switch-
on time is inverted. Example: PWM = 30%, cycle time = 10 minutes -> Switch-on time
= 7 minutes, switch-off time = 3 minutes.
On deenergised closed valve drives, command values are not inverted, in accord-
ance with the 1-bit data format. Example: Command value ON -> Output switched
on, Command value OFF -> Output switched off.
Heating actuator 6-gang with controller | Order no. 2139 00 | 21393100
Image 16: Ideal course of the valve stroke for a
Cycle time < Adjusting cycle time
Page 72 of 257
Advertisement
Table of Contents
