Samson 3785 series, Mounting And Operating Instructions

Page: 10 / 80

2. Attaching the positioner
The positioner can be attached either di-
rectly to a SAMSON Type 3277 Actuator,
or according to NAMUR (IEC 60534-6), to
control valves with casted yokes or rod-type
yokes.
In combination with an intermediate piece,
the device can also be attached as rotary
positioner to rotary actuators.
Since the standard positioner unit is de-
livered without accessories, refer to the re-
quired mounting parts and their order num-
bers in the corresponding tables.
NOTE:
The positioner does not have its own vent-
ing plug, so that the air is exhausted to the
atmosphere through the venting plugs lo-
cated on the accessories (see also Figs. 3, 5
and 6).
A
filter check valve for the exhaust air is in-
cluded with each positioner (underneath the
transparent cover on the back of the posi-
tioner.
Replace the standard venting plug included
in the accessories with this filter check valve.
This is necessary to achieve the IP 65 de-
gree of protection by preventing dirt and
moisture from entering the device.
2.1 Direct attachment to Type
3277 Actuator
For the selection of the required mounting
parts, refer to tables 1, 2 and 3 on page
13.
When looking at the signal pressure connec-
tion or the switchover plate respectively (ac-
tuator 120 cm
2 ) from the top, the posi-
tioner must be attached to the left side of
the actuator.
The
arrow on the black case cover (Fig. 11)
should then point
towards
the
diaphragm
chamber.
Exception:
Control valves in which the plug
closes the seat area when the actuator stem
retracts. In this case, the positioner has to
be attached to the right side of the yoke,
i.e. with the arrow pointing away from the
diaphragm chamber.
1. Screw the clamp (1.2) to the actuator
stem, ensuring that the fastening screw
is located in the groove of the actuator
stem.
2. Screw the associated lever D1 or D2
(for 700 cm 2 actuator) to the trans-
mission lever of the positioner.
3. Fasten distance plate (15) with seal to-
wards the actuator yoke.
4. Place positioner on the plate so that the
lever D1 or D2, will slide centrically
over the pin of the clamp (1.2). Then
screw to distance plate (15).
5. Mount cover (16).
10
EB 8382-1 EN
Attaching the positioner