12.4.4 Corrective measures Table 3
Fault profile (symptoms) Possible cause Corrective measures
● Actuator does not move. ● Compressed air < 1.4 bar ● Set pressure of supply air PZ to
> 1.4 bar.
● Piezo valve does not switch
(however, a gentle clicking sound
can be heard when the or
button is pressed in "Manual" mode.)
● Restrictor valve turned off (screw at
the right endstop)
● Open the restrictor screw by turning
it anticlockwise, see leaflet, Fig.
"Device view ⑥".
● Dirt in the pneumatic block ● Repair or a new device; clean and/or
replace the built-in fine screens.
● A piezo valve is switched constantly
in stationary automatic mode
(constant setpoint) and in "Manual"
mode.
● Pneumatic leakage in the positioner
- actuator system; start the leakage
test in "RUN 3" (initialization).
● Rectify leakage in the actuator
and/or feed line.
● In case of an intact actuator and tight
feed line: Repair or new device
● Dirt in the pneumatic block ● See above
Fault table 3
See also
Repair/Upgrading (Page 244)
12.4.5 Corrective measures Table 4
Fault profile (symptoms) Possible cause(s) Corrective measures
● In stationary automatic mode
(constant setpoint) and in "Manual"
mode, both piezo valves continually
switch alternately, and the actuator
oscillates around an average value.
● Stiction of the packing gland from
the control valve or actuator too large
● Reduce stiction or increase
deadband of positioner (parameter
"dEbA") until the oscillation stops.
● Looseness (play) in the positioner/
actuator/control valve system
● Part-turn actuator: Check for firm
seating of set screw on coupling
wheel.
● Linear actuator: Check for firm
seating of lever on positioner shaft.
● Correct any other play between the
actuator and the control valve.
● Actuator too fast ● Increase travel times using throttle
screws.
● If a quick travel time is needed,
increase the deadband (parameter
"dEbA") until the oscillation stops.
● Positioner doesn't move control
valve to the stop (at 20 mA).
● Supply pressure too low. Load on
the feeding controller or system
output is too low.
● Increase supply pressure, insert
ballast converter
● Select 3/4-wire mode
Error table 4
Diagnostics and troubleshooting
12.4 Fault correction
SIPART PS2 with PROFIBUS PA
Operating Instructions, 05/2019, A5E00127926-AC 279
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