Samson 3767 - Connections; Pneumatic Connections

34 EB8355-2EN
Connections
4 Connections
4.1 Pneumaticconnections
The pneumatic connections are optionally
designedasaborewith¼NPTorG¼
thread.Customaryttingsformetalorcop-
pertubingorplastichosescanbeused.
NOTICE
The supply air must be dry and free
from oil and dust. The maintenance
instructions for upstream pressure
reducing stations must be observed.
Blow through all air pipes and hoses
thoroughly before 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
xed.Forattachmentaccordingto
IEC60534-6(NAMUR),thesignalpressure
canberoutedtoeitherthetoporbottom
diaphragmchamberoftheactuator,
dependingontheactuator'sfail-safeaction
"actuator stem extends" or "actuator stem
retracts".
Exhaustair
Modelswithindex3767-x...x.03 and higher
are equipped with a hinged cover without its
own exhaust air hole. The exhaust air con-
nections for these models are included in the
accessories.
The vent plug is located on the plastic cover
of the actuator for direct attachment, where-
as for NAMUR attachment, it is located on
the adapter housing. The vent plug is located
on the intermediate piece or reversing ampli-
erforattachmenttorotaryactuators.
NOTICE
If you intend to replace older models
with index 3767-x...x.02 or lower,
the mounting parts may need to be
replaced as well.
4.1.1 Pressuregauges
To precisely tune the positioner, we recom-
mend installing pressure gauges for the sup-
ply air and signal pressure.
The required parts are listed as accessories
inTable4,Table5andTable7.
4.1.2 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writtenonthenameplate
either as the spring range or signal pressure
range. The operating direction is marked FA
or FE,orbyasymbol.
Actuatorstemextends(FA):
Fail-close
(forglobeandanglevalves)
Required supply pressure =
Upperbenchrangevalue+0.2bar,
atleast1.4bar.