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1.2 Start-up
The positioner must be initialized to use the
full scope of the valve diagnostics. During
initialization the positioner adapts itself opti-
mally to the friction conditions and the signal
pressure required by the control valve.
The positioner can be initialized using one of
the following initialization modes: maximum
range (MAX), nominal range (NOM) and
manual adjustment (MAN).
− Maximum range (MAX)
Initialization mode for simple start-up of
valves with two clearly defined mechani-
cal end positions, e.g. three-way valves
− Nominal range (NOM)
Initialization mode for all globe valves
− Manually selected range (MAN)
Initialization mode for globe valves re-
quiring OPEN position to be entered
manually
The application type, pressure limit and the
start-up parameters required for the selected
initialization must be entered to initialize the
positioner.
Note:
Positioner start-up is described in de-
tail in the mounting and operating in-
structions (see u EB 8384-3S EN).
During positioner initialization, the propor-
tional-action coefficient Kp and deriva-
tive-action time Tv levels are optimally set. If
the positioner tends to overshoot impermissi-
bly due to other disturbances, the propor-
tional-action coefficient and derivative-action
EB 8389S EN
time can be adapted accordingly. Increment
the derivative-action time until the desired
behavior is reached. When the maximum
value of 4 is reached for the derivative-ac-
tion time, the proportional-action coefficient
can be reduced in steps.
NOTICE
Changing the proportional-action co-
efficient influences the set point de-
viation!
Start-up
− Application type (Code 49 - h0):
[Control valve], Open/Close valve
− Initialization mode (Code 6):
[Maximum range (MAX)], Nominal range
(NOM) or Manual adjustment (MAN)
− Pin position (Code 4): [Off], 17, 25, 35, 50,
70, 100, 200, 300 mm, 90°
− Pressure limit (Code 16): [Off], 3.7, 2.4, 1.4 bar
Settings > Positioner > Performance
characteristics
− Required proportional-action coefficient Kp
(level) (Code 17): 0 to 17, [7]
− Required derivative-action time Tv (level)
(Code 18): Off, 1 to 4, [2]
Description
9
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