3. Connections
3.1 Pneumatic connections
The air connections are either NPT 1/4 or
G 1/4 tapped holes. The customary fittings
for metal and copper tubes or plastic hoses
can be used.
NOTE
The supply air must be dry and free from oil
and dust. The maintenance instructions for
upstream pressure reducing stations must
be adhered to. Carefully purge all air tubes
and hoses before connecting them.
If the positioner is attached directly to the
Type 3277 Actuator, the connection of the
positioner output pressure to the actuator is
fixed. For NAMUR attachment, the signal
pressure can be applied to either the upper
or lower diaphragm chamber of the actua-
tor, depending on the actuator’s fail-safe ac-
tion (either "Actuator stem retracts" or "stem
extends").
Exhaust air:
The exhaust air connection of
the positioner is located at the mounting kit.
For direct attachment of the positioner, a
vent plug is located at the plastic cover of
the actuator. For NAMUR attachment, the
vent plug can be found at the adapter hous-
ing and for attachment to rotary actuators,
it is either located at the intermediate piece
or the reversing amplifier.
To guarantee the IP 65 degree of protec-
tion, the vent plug must be replaced with
the filter check valve included with the de-
vice. See also chapter 2 on page 10.
3.1.1 Pressure gauge
To monitor the positioner operation, it is
recommended that pressure gauges for sup-
ply air and signal pressure indication to the
positioner be connected. These parts are
listed as accessories in Table 3, 4 or 6.
Fig. 8
⋅
Mounting the pressure gauge
2...3mm
Nut Throttle Filter
24
EB 8382-1 EN
Connections
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