Samson Type 3766 Mounting And Operating Instructions - Attachment to Control Valve
2
Attachment to control valve
The positioner is attached either directly to
SAMSON Type 3277 Actuator or to valves
with cast yokes or with rod-type yokes in ac-
cordance with IEC 60534-6-1 (NAMUR).
When combined with an intermediate piece,
the device can also be attached to rotary ac-
tuators as a rotary positioner.
As the positioner is also available as a basic
unit without accessory equipment, refer to
the tables on the following pages for both
the required mounting parts and their asso-
ciated order numbers.
Do not remove the protective cover on the
back of the positioner before actually start-
ing to attach the positioner.
Mounting position and operating direction
The operating direction of the positioner
also determines its mounting position on the
actuator as illustrated in Figs. 3, 4 and 6.
The turnboard (7 in Fig. 2) at the positioner
must be mounted correspondingly.
For an increasing input signal (reference
variable), the signal pressure p
st
can either
be increasing (direct action >>) or decreas-
ing (reverse action <>).
This also applies when the reference vari-
able decreases: direct action >> causes the
signal pressure to decrease, reverse action
<> causes the signal pressure to increase.
On the turnboard (7), the operating direc-
tion is indicated by symbols (direct >>, re-
verse <>).
Depending on the position of the turnboard,
the adjusted operating direction and the as-
sociated symbol become visible.
If the required operating direction does not
correspond to the visible symbol, or if you
want to change the operating direction, re-
move the fastening screw at the turnboard,
turn the board by 180° and refasten the
turnboard with the screw. Make sure the
three rubber gaskets inserted in the housing
remain in position.
NOTICE
When any subsequent changes are made,
e.g. reversing the operating direction of the
positioner control loop or changing the actu-
ator from “Actuator stem extends” to “Actu-
ator stem retracts” or vice versa, the
positioner's mounting position must be
changed accordingly.
2.1
Direct attachment to Type
3277 Actuator
Required accessories are listed in Tables 1
to 4 on page 14.
The attachment of the positioner either on
the left or right side of the actuator (always
looking at the signal pressure connection or
switchover plate) is determined by the re-
quired operating direction of the positioner,
i.e. >> or <>.
1. Screw the clamp (1.2) to the actuator
stem. Make sure that the fastening screw
is located in the groove of the actuator
stem.
10
EB 8355-1 EN
Attachment to control valve