Fault And Remedy - Siemens SIPART PS2 Series Operating Instructions Manual

11.4

Fault and remedy

Fault profile (symptoms)
Positioner remains in "RUN 1".
Positioner remains in "RUN 2".
Positioner remains in "RUN 3".
Positioner remains in "RUN 5", does not
go to "FINISH" (waiting time > 5 min.).
"CPU test" flashes on the local display
approximately every 2 seconds.
The pneumatic block does not switch.
In the manual and automatic modes, the
actuator cannot be moved or can be
moved only in one direction.
SIPART PS2 with 4 to 20 mA/HART
Operating Instructions, 11/2019, A5E00074631-AE
Possible cause(s)
● Initialization started from the end po‐
sition
● The response time of a maximum of
1 minute was not observed
● Supply pressure PZ not connected
or supply pressure PZ too low.
● Compressed air line blocked, e.g.
solenoid valve
● Transmission ratio selector and pa‐
rameter 2
● "YAGL" and the real stroke do not
match.
● Incorrectly set stroke on the lever
● The pneumatic block does not
switch.
● Actuator travel time is too high
● "Gap" (play) in the positioner - ac‐
tuator - control valve system
● Diagnostic value "9.TUP" or
"10.TDOWN" < 1.5 s
● Water in the pneumatic block (due to
wet compressed air)
● Moisture in the pneumatic block
Diagnostics and troubleshooting
11.4 Fault and remedy
Remedy
● A waiting time of up to 1 minute is
required
● Do not start initialization from the
end position.
● Ensure supply pressure PZ.
● Free up blocked lines
● Check settings: Parameters 2 and 3
● Check the stroke setting on the lever
● Open the restrictor completely
and/or set supply pressure PZ to the
highest permissible value.
● Use a booster if required.
● Part-turn actuator: Check for firm
seating of set screw on coupling
wheel
● Linear actuator: Check for firm seat‐
ing of lever on positioner shaft.
● Correct any other play between the
actuator and the control valve.
● Set the traversing velocity to > 1.5 s
using the internal restrictor.
● At an early stage, this fault can be
rectified with subsequent operation
using dry air, in a temperature cabi‐
net at 50 to 70 °C if required.
● Otherwise: Repair
235