Starting Point And Input Signal (Reference Variable) - Samson 4765 Mounting And Operating Instructions

Operation
If the operating direction of the required
function does not match the symbol or if the
operating direction is to be changed,
proceed as follows:
1. Remove both screws of the cover plate,
and lift off the nozzle block (10) along
with the cover plate.
2. Reinstall the nozzle block turned 180° to-
gether with the cover plate and fasten.
Make sure that the nozzle block and flapper
are correctly located above or below the
feeler pin (9.1) as shown in Fig. 10.
If the operating direction is to be changed
after the initially determined arrangement of
positioner and actuator, note that the
positioner must be mounted in a different lo-
cation and the nozzle block must be turned.
Always consider the location of the lever (1)
and the plate (20), "lever on top of plate" or
reversed "plate on top of lever" as shown in
Figs. 6 to 9.
Cover plate
Nozzle block
Operating direction increasing/increasing (direct <<)
feeler pin on top of flapper
Fig. 10 · Position of nozzle block, cover plate removed
12
EB 8359-1 EN
Range spring
Feeler pin
4.2 Starting point and input
signal (reference variable)
The attached lever and the installed range
spring of the positioner correspond to the
rated valve travel and the reference variable
(input signal) according to Table 1.
In standard operating mode, the reference
input span is 100 % = 0.8 bar. A narrower
span of, for example 50 % = 0.4 bar, is
only required in split-range operation.
This span can be changed by subsequently
replacing the range spring (see section 4.4).
On adjusting the positioner, the travel must
be adjusted to the reference variable and
vice versa.
With a reference input span from 0.2 to
1 bar, the valve must have passed full travel
from 0 to 100 % where the starting point
then begins at 0.2 bar and the span ends at
1 bar.
Flapper
Marking
Operating direction increasing/decreasing (reverse <>)
flapper on top of feeler pin