Malfunction; Troubleshooting; Emergency Action - Samson 4763 Mounting And Operating Instruction

8 Malfunction

DANGER
!
Risk of fatal injury due to the ignition of an
explosive atmosphere.
Î Installation, operation or maintenance of
the positioner must only be performed by
personnel who has undergone special
training or instructions or who is autho-
rized to work on explosion-protected de-
vices in hazardous areas.
WARNING
!
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.
EB 8359-2 EN

8.1 Troubleshooting

Î See Table 8-1
Note
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.
Tip
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.
Malfunction
9-1