Samson foundation 3787, Монтаж и эксплуатация, Страница: 30 / 96

4.2 Write protection and simula-
tion switches
There are two microswitches inside the
hinged cover to activate the write protection
and enable simulation.
When the write protection switch is ON, the
configuration data of the positioner are
write-protected and cannot be overwritten.
The switch must be set to OFF before any
configuration data can be changed over the
communications.
The simulation switch enables the simulation
of the position value for Analog Output
Function Block using the Simulate par-
ameter.
4.3 Activate/deactivate forced
venting function
For models with index .0 3 or higher:
1. Remove cover plate on the inside of the
positioner lid by unscrewing the four
screws.
2. Unscrew the central screw on the board
and push the board to one side.
3. Set switch to desired position:
1 ENABLED > Function activated
2 DISABLED > Function deactivated.
4.4 Default setting
All parameters are set to default values. See
chapter 7 on description of parameters.
Note!
Manual operation and activated final posi-
tion functions can cause the actuator to
filled with the maximum supply pressure.
Should this lead to impermissible forces oc-
curring, the supply pressure must be re-
stricted by a reducing station.
4.4.1 Adjusting mechanical zero
Note!
Zero must be calibrated when the valve is
closed (with actuator stem extended in three-
way valves).
Firmly push the zero switch, located on
the cover plate inside the positioner, in
the direction indicated by the arrow as
far as it will go once. The yellow pointer
will then be aligned with the white line.
For control valves which are open in their in-
itial position, e.g. when the actuator’s fail-
safe position is "actuator stem retracts", the
positioner must be first supplied with air.
The manual operation function must then be
activated so that the supply pressure builds
up and moves the valve to the closed posi-
tion. Then press the zero switch.
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EB 8383-1 EN
Operation