Baelz Automatic 6490B Device Manual page 21

Page 21
Device manual 6490B / 6490B-y / 6590B
3.15.4 Start up behaviour with setpoint ramp SP.r
Fig. 3)
A soon as the STOP command is inactive the setpoint SP is automatically equated with the
current temperature PV (2).
Therefore no control deviation Xw is given for the controller and no OPEN pulse is generated.
Then the setpoint returns to the adjusted setpoint SP according to the setpoint ramp SP.r.
If the speed of the setpoint ramp SP.r (gradient) is adjusted 0.75 to 0.5 times of the natural temperature
rise rate (temperature change in fig. 1), the setpoint will be reached within a very short time without any
considerable overshoot.
3.15.5 Start up behaviour with delta setpoint dSP and setpoint ramp SP.r
It is possible to combine delta setpoint and setpoint ramp.
A soon as the STOP command is inactive the setpoint SP is equated with the current temperature and
an OPEN or CLOSE pulse is given according to the adjusted setpoint lowering value dSP.
Then the setpoint returns to the adjusted setpoint SP according to the setpoint ramp SP.r.
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