Samson 3730-6, Mounting And Operating Instructions

Page: 45 / 124

5 Connections
WARNING!
Mount the positioner, keeping the following
sequence:
1. Mount the positioner on the control valve
2. Connect the supply air
3. Connect the electrical power
4. Perform the start-up settings
The connection of the electrical auxiliary
power may cause the actuator stem to move,
depending on the operating mode.
Do not touch the actuator stem or obstruct it
to avoid risk of injury to hands or fingers.
5.1 Pneumatic connections
NOTICE
Follow the instructions below to avoid dama-
ging the positioner.
– The threaded connections in the
positioner housing are not designed di-
rect air connection!
– The screw glands must be screwed into
the connecting plate, the pressure gauge
mounting block or the connection block
from the accessories.
The air connections are optionally de-
signed as a bore with ¼ NPT or G ¼
thread.
The customary fittings for metal and cop-
per pipes or plastic hoses can be used.
– The supply air must be dry and free from
oil and dust.
The maintenance instructions for up-
stream pressure reducing stations must
be observed.
If the positioner is attached directly to the
Type 3277 Actuator, the connection of the
positioner's output pressure to the actuator is
fixed. For attachment according to
IEC 60534-6 (NAMUR), the signal pressure
can be routed to either the top or bottom di-
aphragm chamber of the actuator, depend-
ing on the actuator's fail-safe action "Actua-
tor stem extends" or "Actuator stem re-
tracts".
For rotary actuators, the manufacturer's
specifications for connection apply.
5.1.1 Signal pressure gauges
To monitor the supply air (Supply) and sig-
nal pressure (Output), we recommend that
pressure gauges be attached (see accesso-
ries in Tables 2 to 6).
5.1.2 Supply pressure
The required supply air pressure depends on
the bench range and the actuator's operat-
ing direction (fail-safe action).
The bench range is registered on the name-
plate either as spring range or signal pres-
sure range depending on the actuator. The
direction of action is marked FA or FE , or by
a symbol.
Note: If the supply pressure p
s
is lower than
the upper spring range value detected dur-
ing plotting of the valve signature, PLOW is
indicated under Code 0 .
EB 8384-6 EN
45
Connections