10. Corrective action
10.1. Faults during commissioning
Table 11:
Faults during operation/commissioning
RemedyDescription/causeFaults
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)
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.
In spite of correct setting of mechanical limit
switching, actuator operates into the valve or
actuator end position
Check setting, if required, reset end positions.
Refer to < Check switches> and replace them,
if required.
Switch is defective or switch setting is incor-
rect.
Limit and/or torque switches do not trip.
10.2. Fuses within the actuator
Versions with positioner (PEL100 or PEL-GL) include a fuse for protecting the
positioning electronics. Please refer to wiring diagram for indications on the fuse.
10.3. Motor protection (thermal monitoring)
For thermal protection against overheating, the actuator is either equipped with a
stall-proof motor or a thermoswitch for temperature monitoring within the motor
winding.
For motor versions with stall-proof motors, the preceding overcurrent protection
device must be lower than factor five of the nominal motor current.
For motor version with thermoswitches, the thermoswitch interrupts the motor power
supply and the actuator stops as soon as the maximum admissible winding
temperature has been reached.
The motor has to cool down before operation can be resumed.
24
EQ 40 – EQ 150
Corrective action EQ 300 – EQ 600