EB 8355-2 EN 9-1
Malfunction
8 Malfunction
Risk of fatal injury due to the ignition of an
explosive atmosphere.
Î Observe EN60079-14 (VDE0165,
Part1) for work on the positioner in haz-
ardous areas.
Î Work in hazardous areas must only be
performed by personnel who has under-
gone special training or instructions or
who is authorized to work on explo-
sion-protected devices in hazardous ar-
eas.
Crush hazard arising from moving parts on
the valve.
Î Do not touch any moving valve parts
while the control valve is in operation.
Î Before performing any mounting or in-
stallation work on the positioner, put the
control valve out of operation by discon-
necting and locking the supply air and
control signal.
Î Do not impede the movement of the actu-
ator and plug stem by inserting objects
into the yoke.
8.1 Troubleshooting
Î See Table 8-1
Contact SAMSON's After-sales Service for
malfunctions not listed in the table.
8.2 Emergency action
Upon failure of the air supply or electric sig-
nal, the positioner vents the actuator, causing
the valve to move to the fail-safe position de-
termined by the actuator.
Emergency action in the event of valve or ac-
tuator failure is described in the associated
valve and actuator documentation.
Î Plant operators are responsible for emer-
gency action to be taken in the plant.
DANGER
!
WARNING
!
Note
Tip