Samson 3761, Монтаж и эксплуатация

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2.1 Determining the operating di-
rection
Important!
The positioner with either single-acting or
double-acting output is fixed and cannot be
changed by subsequently adding or remov-
ing an amplifier.
Single-acting positioners:
The operating direction of the positioner is
determined by the mounting position of the
amplifier. When the input signal (reference
variable) increases, the signal pressure p
st
can either increase (direct operating direc-
tion) or decrease (reverse operating direc-
tion).
The same applies when the input signal de-
creases. For direct operating direction, the
signal pressure decreases whereas it in-
creases for reverse operating direction.
For direct operating direction, screw the am-
plifier in mounting position
1 (Fig. 2); for re-
verse operating direction, screw the ampli-
fier in mounting position
2 . Screw the cover
plate onto the unoccupied position so that
the associated supply air bore is sealed.
Note!
When relocating the amplifiers, make abso-
lutely sure that both O-rings remain in the
base of the housing.
Double-acting positioners:
The operating direction is determined by the
assignment of the signal pressure out-
puts
1 38 and 2 38 to the two connections
(y1 and y2) of the rotary actuator.
Note!
The designation of the signal pressure con-
nections on the rotary actuator varies de-
pending on the manufacturer.
In Figs. 5 and 6, y1 and y2 have been as-
signed the following functions:
Single-acting actuator
Increasing the signal pressure at y1 opens
the valve if the closure member rotates coun-
terclockwise.
Double-acting actuator
Increasing the signal pressure at y1 and de-
creasing the pressure at y2 opens the valve
if the closure member rotates counterclock-
wise; or
increasing the signal pressure at y2 and de-
creasing the pressure at y1 opens the valve
if the closure member rotates clockwise.
EB 8386 EN
9
Attachment to rotary actuators