Electropneumatic Positioner Part Manual

Operation
138
SIP ART PS2 Manual
A5E00074631--06
Fault indication
(symptoms)
possible cause(s) Remedies
• Actuator does not move • Compressed air < 1.4 bar • Set supply air pressure to
> 1.4 bar.
• Piezo valve(s) do(es) not
switch (quiet “clicking” can
be heard however when
the + or – button is pressed
• Reactor valve(s) closed
(screw(s) at the right-hand
stop)
• Open reactor screw(s) (see
leaflet, figure “device v iew (6)”
by turning it/them
anti-clockwise.
t
h
e
+
o
r
b
u
t
t
o
n
i
s
p
r
e
s
s
e
d
in manual mode).
• Dirt in the pneumatic block • Repair (see chapter 5,
page 145) or new device;
integrated fine screen,
also replace and clean.
• A piezo valve switches
continuously in stationary
automatic mode (constant
setpoint) and in manual
mode.
• Pneumatic leakage in the
positioner – actuator system
Start leakage test in “RUN 3”
(initialization)!!!
• Eliminate leakage in the
actuator and/or supply line
• If the actuator is intact and the
supply line is leak-tight:
Repair (see chapter 5,
page 145) or new device
• Dirt in the pneumatic block
(see above)
• see above
Table 7
Fault indication
(symptoms)
possible cause(s) Remedies
• Both piezo valves switch
continuously and
alternately in s tationary
automatic mode (constant
• Too much slipstick of stuffing
box of control valve or actuator
• Reduce slipstick or increase
dead zone of SIPART PS 2
(dEbA parameter) until
oscillation stops.
a
u
t
o
m
a
t
i
c
m
o
d
e
(
c
o
n
s
t
a
n
t
setpoint) and in manual
mode, actuator oscillates
around a mean value.
• Batches (play) in the positioner
-- actuator – control valve
system
• Part--turn actuator:
Check if set screw of the
coupling wheel is inserted
firmly
• Linear actuator:
Check if lever is connected
firmly to positioning shaft.
• Eliminate any other play
between actuator and control
valve.
• Actuator too fast • Increase actuating times via
reactor screws.
• If fast actuating time is
required, increase dead zone
(dEBA parameter) until
oscillation stops.
• SIPART PS 2 does not
“drive” control valve up to
the stop (at 20 mA).
• Supply pressure too low.
• Load of the feeding controller
or system output is too low.
• Increase s upply pressure
• Interconnect load converter
• Select 3/4 transmitter
operation
Table 8