Corrective Measures Table 4 - Siemens 6DR50 Series Operating Instructions Manual

10.4.5

Corrective measures Table 4

Fault profile (symptoms)
In stationary automatic mode (con-
•
stant setpoint) and in "Manual"
mode, both piezo valves continually
switch alternately, and the actuator
oscillates around an average value.
Positioner doesn't move control
•
valve to the stop (at 20 mA).
Error table 4
See also
Cleaning of the screens (Page 236)
SIPART PS2 with and without HART
Operating Instructions, 09/2014, A5E00074631-12
Possible cause(s)
Stiction of the packing gland from
•
the control valve or actuator too
large
Looseness (play) in the position-
•
er/actuator/control valve system
Actuator too fast
•
Supply pressure too low. Load on
•
the feeding controller or system
output is too low.
Alarm, error, and system messages
10.4 Fault correction
Corrective measures
Reduce stiction or increase dead-
•
band of positioner (parameter "dE-
bA") 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 travel times using throttle
•
screws.
If a quick travel time is needed,
•
increase the deadband (parameter
"dEbA") until the oscillation stops.
Increase supply pressure, insert
•
ballast converter
Select 3/4-wire mode
•
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