Siemens SIPART PS2 FF Betriebsanleitung Seite 34

C.3.5 Remedial measures table 4
Symptoms
● In stationary automatic mode
(constant setpoint) and in manual
mode, both piezo valves continually
switch alternately, and the actuator
oscillates around a mean value.
● Positioner doesn't move control
valve to the stop (at 20 mA).
Error table 4
C.3.6 Remedial measures table 5
Fault profile (symptoms)
● Zero point displaces sporadically
(> 3%).
● The device function has completely
failed: No representation on the
display either.
Fault table 5
C.4 Certificate
The certificates can be found on the enclosed CD and on the Internet under:
Certificates (http://www.siemens.com/processinstrumentation/certificates)
34
Possible cause(s)
● Sticking friction of the packing gland
from the control valve or actuator
too large
● Looseness (play) in the
positioner/actuator/control valve
system
● Actuator too fast
● Supply pressure too low. Load on
the feeding controller or system
output is too low.
Possible cause(s)
● Impact or shock loads result in
accelerations so high that the
friction clutch moves, e.g. due to
"vapor shocks" in vapor lines.
● Electrical auxiliary power supply is
not adequate.
● In case of very high continuous
loads due to vibrations
(oscillations):
● Screws of the electrical connecting
terminals may be loosened.
● Electrical connecting terminals
and/or electronic components may
be knocked out.
Remedial measures
● Reduce friction or increase dead
zone of positioner (parameter
"dEbA") until the oscillation stops.
● 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.
● Increase actuating times using
throttle screws.
● If a quick actuating time is needed,
increase the dead zone (parameter
"dEbA") until the oscillation stops.
● Increase supply pressure, insert
ballast converter
● Select 3/4-wire mode
Remedial measures
● Rectify the causes for shock loads.
● Re-initialize the position controller.
● Check the electrical auxiliary power
supply.
● Tighten the screws firmly and
secure using sealing wax.
● Repair
● For prevention: Install the positioner
on the damping pads.
Functional safety for SIPART PS2 FF
A5E00489774-02, 10/2013