Corrective Actions; Faults During Operation/Commissioning - AUMA SQEx 05.2 Operation Instructions Manual

12 Corrective actions

12.1 Faults during operation/commissioning

Table 21: Faults during operation and commissioning
Faults
Mechanical position indicator cannot
be set.
In spite of correct setting of mechan-
ical limit switching, actuator operates
into the valve or actuator end position.
No value can be measured at measur-
ing points of the RWG.
Measuring range 0/4 – 20 mA or max-
imum value 20 mA at position trans-
mitter cannot be set or supplies an in-
correct value.
the measuring range 0/4 – 20 mA at
EWG position transmitter cannot be
set.
Limit and/or torque switches do not
trip.
Handwheel rotates on the shaft
without transmitting torque.
Description/cause
Reduction gearing is not suitable for actuator
swing angle.
The overrun was not considered when setting the
limit switching.
The overrun is generated by the inertia of both the
actuator and the valve and the delay time of the
actuator controls.
The current loop across the RWG is open.
(Position feedback 0/4 – 20 mA is only possible if
the current loop is closed across the RWG.)
Reduction gearing is not suitable for actuator
swing angle.
The LED on the EWG either flashes in setting
mode a) single flash or b) triple flash:
a) EWG is not calibrated.
b) Magnet positions of EWG are not aligned.
Switch is defective or switch setting is incorrect.
Actuator in version with overload protection for
manual operation: Shear pin rupture due to ex-
cessive torque at handwheel.
Switch check
The red test buttons [1] and [2] are used for manual operation of the switches:
Figure 45: Test buttons
[1]
1. Turn test button [1] in direction of the DSR/TSC arrow (clockwise closing): Torque
switch CLOSE trips.
2. Turn test button [2] in direction of the DÖL/TSO arrow (counterclockwise opening):
Torque switch OPEN trips.
If the actuator is equipped with DUO limit switching (option), the intermediate position
switches WDR/LSA and WDL/LSB will be operated at the same time as the torque
switches.
1. Turn test button [1] in direction of the WSL/LSC arrow (clockwise closing): Limit
switch CLOSED trips.
2. Turn test button [2] in direction of the WÖL/LSO arrow: Limit switch OPEN trips.
Remedy
Exchange reduction gearing.
• Determine overrun: Overrun = travel covered
from switching off until complete standstill.
• Set limit switching again considering the over-
run. (Turn handwheel back by the amount of
the overrun)
• Connect link across RWG to XK (terminals
23/24).
• Connect external load to XK, e.g. remote in-
dication.
• Observe maximum load R
Exchange reduction gearing.
Request AUMA Service.
Check setting, if required, reset end positions.
Refer to Switch check [} 45], or replace switches,
if required.
Dismount handwheel. Replace overload protection
and remount handwheel.
Corrective actions
.
B
[2]
45