Samson 2780-1, Mounting And Operating Instructions, Page: 29 / 52

EB 5840 EN 7-1
Malfunctions
7 Malfunctions
7.1 Troubleshooting
Malfunction Possible reasons Recommended action
Actuator stem does not
move on demand.
Actuator is blocked. Check attachment.
Unblock the actuator.
WARNING! A blocked actuator (e.g. due to seizing
up after remaining in the same position for a long
time) can suddenly start to move uncontrollably.
Injury to hands or fingers is possible if they are
inserted into the actuator or valve.
Before trying to unblock the actuator stem, discon‑
nect and lock the pneumatic air supply as well as
the control signal. Before unblocking the actuator
stem, release any stored energy in the actuator (e.g.
spring compression). See 'Relieving the spring com‑
pression in the actuator' in the 'Removal' section.
Insufficient signal
pressure
Check the signal pressure.
Check the signal pressure line for leakage.
Signal pressure not
connected to the correct
diaphragm chamber.
See 'Signal pressure routing' in the 'Design and
principle of operation' section.
Diaphragm in the
actuator defective
See 'Replacing the diaphragm' in the 'Servicing'
section.
Actuator stem does not
stroke through its com‑
plete travel range.
Insufficient signal
pressure
Check the signal pressure.
Check the signal pressure line for leakage.
Incorrect setting of
valve accessories.
Check the actuator without valve accessories.
Check the settings of the valve accessories.
Contact our after‑sales service for malfunctions not listed in the table.
Note