Samson 4763, Инструкция по монтажу и эксплуатации

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EB 8359-2 EN 5-11
Installation
b) Actuator with “actuator stem
retracts” (FE) fail-safe action
When using an actuator with fail-safe action
"actuator stem retracts", the diaphragm
chamber must be pressurized with a signal
pressure that is high enough to tightly close
the valve against the upstream pressure in
the plant.
Î
Operating direction <<: Upper range
value of set point 20 mA
Î
Operating direction <>: Lower range val -
ue of set point 4 mA
The required signal pressure is either indicat-
ed on the positioner label or it can be rough-
ly calculated as described in section 5.4.2.
Starting point, e.g. 20 mA
1. Set the input signal at the ammeter to
20 mA.
Turn the zero adjustment screw (4) until
the plug stem just starts to move out of its
initial position.
2. Increase the input signal and slowly re-
duce it again to 20 mA. Check whether
the plug stem starts to move at exactly
20 mA.
Correct any deviation at the zero adjust
-
ment screw (4). Turning it counterclock-
wise causes the plug stem to move from
its end position earlier; turning it clock-
wise causes it to move from its end posi-
tion later.
Upper range value (span), e.g. 4 mA
3. Once the starting point has been set, in-
crease the input signal to 4 mA at the
ammeter.
At exactly 4 mA, the plug stem must
stand still, having moved through 100 %
travel (watch the travel indicator at the
valve).
4. If the upper range value is incorrect,
move the pin (2) to correct it. Readjust
20 mA and turn the zero adjustment
screw (4) until the pressure gauge indi-
cates the
required signal pressure .
If no pressure gauge has been installed,
set the starting point to 19.5 mA instead.
5.7 Electrical connection
For electrical installation, observe the rele-
vant electrotechnical regulations and the ac-
cident prevention regulations that apply in
the country of use. In Germany, these are
the VDE regulations and the accident pre-
vention regulations of the employers’ liability
insurance.
Incorrect electrical connection will render
the explosion protection unsafe.
Î
Adhere to the terminal assignment.
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Do not undo the enameled screws in or
on the enclosure.
WARNING !