Smooth Automatic/Manual Mode Changeover; Smooth Changeover Between The Internal And External Reference Variable; Readjusting The Controller's Zero Point - Samson 3430 Operating Instructions Manual

Commissioning
Note!
The T restriction must be completely opened
n
with a P/PI controller is switched over to P
action to allow the operating point adjuster
to work without delay.
Version with w-dependent operating point
This version does not need to be adjusted
since the operating point automatically fol-
lows the set point w.
3.2 Smooth automatic/manual
mode changeover
(only for controller station with manual/au-
tomatic changeover, Fig. 4)
The smooth switchover ensures that no pres-
sure surges can reach the valve when the
manual/automatic switch is activated as fol-
lows:
Changeover from automatic to manual
Use the manual adjuster (1.7) to adjust
signal pressure manual yH until the differen-
tial pressure indicator (1.8) is zero. Switch
over to manual at the switch.
Differential pressure indicator
With Without deviation
Changeover from manual to automatic
If the plant is to be controlled manually to
the required value, the automatic signal
pressure yA must be matched to the manual
signal pressure yH by adjusting the set point
10
EB 7030 EN
adjuster (1.4).
The switch (1.6) can only be set to automatic
after the differential pressure indicator (1.8)
is at zero.
Set the set point again to the required value.
3.3 Smooth changeover between
the internal and external re-
ference variable
When combining the fixed set point control
and follower control, the Type 3432 Con-
troller Station is equipped with a w
switch, a pressure adjuster and a differential
pressure indicator (Fig. 10).
The differential pressure indicator must first
be brought to zero by activating the pres-
sure adjuster in order to switch between the
reference variables.
3.4 Readjusting the controller's
zero point
Should deviations arise between the actual
value and set point during operation, the
zero point adjustment can be readjusted by
turning the zero screw at the back of the dis-
play unit (5) until the actual value and set
point on the front display are the same
again.
Deviations between the actual value and set
point can also be corrected at the zero point
adjuster (8, Fig. 2) of the controller module.
/w
int ext