Samson TROVIS 3731-3, Mounting And Operating Instructions

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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
The maximum input pressure (supply pres-
sure) is:
– 7 bar for Types 3731-321 and 3731-327
– 6 bar for Type 3731-323
DANGER!
Danger from the formation of an explosive
atmosphere!
The operator of the apparatus must ensure
that the working medium cannot form an ex-
plosive atmosphere, i.e. only such gases
may be used which are free from substances
whose presence in the medium might lead to
the formation of an explosive atmosphere
(e.g. do not use flammable gases, oxygen or
oxygen-enriched gases).
Follow the instructions below to avoid dam-
aging the positioner.
– The screw fittings with ¼ NPT thread can
be screwed directly into the positioner.
In case G ¼ threaded connections are
required, the fittings must be screwed
into the connecting plate (6) or pressure
gauge mounting block or connection
block available from the accessories.
Customary screw-in fittings for metal and
copper pipes or plastic hoses can be
used.
– The supply air must be dry and free from
oil and dust.
The maintenance instructions for upstre-
am pressure reducing stations must be
observed.
Blow through all air pipes and hoses tho-
roughly prior to connecting them.
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.
34
EB 8387-3 EN
Connections