Samson 5857, Mounting And Operating Instructions, Page: 64 / 80

16-4 EB 5857 EN
Annex A (configuration instructions)
16.4 Blockage
16.4.1 Blockage detection
The positioner can only detect a valve blockage after either an initialization ('Start-up and
configuration' section) or a transit time measurement ('Service' folder in 'Start-up' or 'Func -
tions') has been performed after the actuator is started up for the first time.
The positioner detects a valve blockage when the actuator stem extends and with absolute
travel adjustment by comparing the travel after the limit switch has been triggered with the
travel measured on initialization. If the comparison shows that the limit switch was triggered
too early, this indicates that there is a valve blockage. The
red LED blinks:
− Blockage
On
Off
2 4 6 8 10
Time in s
Settings\Actuator\Blockage
Function WE Adjustment range
Blockage detection No No, Yes
16.4.2 Blockage removal
When the Blockage removal function is active, the actuator stem extends and retracts 1 mm
at the adjusted stroking speed three times in sequence. The action is indicated by the yellow
LED (only when the Blockage removal function is active).
− Removing blockage
On
Off
Time in s
Note