Samson 4763, Монтаж и эксплуатация

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4.2 Starting point and input
signal (reference variable)
The attached lever and the installed range
spring of the positioner are assigned to the
values of rated valve travel (mm) and the in-
put signal (% reference variable) as in the
table below.
In standard operation, the reference vari-
able span is 100 % = 16 mA. A smaller
span of, for example, 50 % = 8 mA is only
required for split-range operation (Fig. 13).
The span can be changed by exchanging
the range spring (section 4.4). On making
adjustments to the positioner, the travel must
be adapted to the input signal and vice
versa.
14
EB 8359-2 EN
Operation
Rated travel [mm] Min./max. travel [mm] Reference variable (input signal) Range spring
Standard travels for SAMSON valves with lever I (40 to 127 mm long)
15 7.5 to 15
100 %
50 %
1
2
30 14 to 32
100 %
50 %
2
3
60 30 to 70 100 % 3
Additional travel ranges with lever I and lever extension (40 to 200 mm long)
20 7.5 to 26
100 %
50 %
1
2
40 14 to 50
100 %
50 %
2
3
> 60 30 to 90 100 % 3
100%
0%
4 20mA
Fig. 12 · Standard operation
Reference variable
Input signal
Closed
Travel
Open
100%
0%
4 12 20mA
Fig. 13 · Split-range operation, two valves
operating in opposing directions
Open
Travel
Closed
Valve 2
Valve 1
Dead band