Siemens 6DR55 Series Manual page 130

Operation
Fault description (symp-
toms)
CPU test blinks in the
•
display of the posi-
tioner (ca. every 2
secs)
Piezo valve(s) do not
•
switch
Actuator cannot be
•
moved in manual or
automatic mode, or
only in one direction
Piezo valve(s) do not
•
switch (no soft clicking
can be heard when the can be heard when the
+ or -- keys are
pressed in manual
mode)
Table 4
Fault description (symp-
toms)
Actuator does not
•
move
Piezo valve(s) do not
•
switch (although a
soft clicking can be
heard when the + or --
keys are pressed in
manual mode)
One piezo valve
•
constantly switches in
stationary automatic
mode (constant
setpoint) and in
manual mode
Table 5
128
Possible cause(s)
Water in the valve manifold
•
(from wet compressed air)
Dampness in the valve manifold
•
Screw between cover hood and
•
the valve manifold is not tight or
the hood is jammed
Dirt (swarf, particles) in the
•
valve manifold
Deposits on the contact(s)
•
between the electronics board
and the valve manifold can
occur from abrasion through
continuous stresses from strong
vibrations
Possible cause(s)
Compressed air < 1.4 bar
•
Restrictor(s) closed down
•
(screw(s) at the right end stop)
Dirt in the valve manifold
•
Pneumatic leak in the positio-
•
ner, actuator system, start leak
test in RUN 3 (Initialization)
Dirt in the valve manifold (see
•
above)
Corrective actions
At the early stages the fault can be
•
corrected by subsequent operation
with dry air (when necessary, in a
temperature cupboard at 50 to
70 °C)
Otherwise: Repair see page 160. Otherwise: Repair see page 160.
•
Tighten screw, or release cause of
•
jamming when necessary
Repair see page 160.
•
New device with integrated fine fil-
ter which can be replaced and
cleaned
Clean all contact surfaces with
•
alcohol: when necessary bend the
valve manifold contact springs
back into place
Corrective actions
Set inlet air pressure to > 1.4 bar
•
Open restrictor screw(s) (see leaf-
•
let, Figure "View of device (6)") by
turning to the left
Repair see page 160.
•
New device with integrated fine
filter which can be replaced and
cleaned
Fix leak in the actuator and/or
•
supply line
If the actuator and supply line are
•
intact:
Repair see page 160 or new
device
See above
•
SIPART PS2 PA Manual
A5E00127926--05