Pneumatic Connection - Samson 3277-5 Mounting And Operating Instructions

5.2.2

Pneumatic connection

The maximum permissible supply pressure is
specified in the order confirmation for the
control valve. It is, however, restricted to
6 bar in throttling service. See the 'Opera-
tion' section for restrictions in on/off service.
How and with which accessories the air sup-
ply is connected depends on the actuator
model and its direction of action. See 'Direc-
tion of action and signal pressure routing' in
the 'Design and principle of operation' sec-
tion.
Determine the lower and upper signal pres-
sure range values before connecting the sup-
ply air:
− The lower signal pressure range value
corresponds to the minimum value of the
bench range or operating range (when
the travel range is adapted, see 'Adapt-
ing the travel range' in the 'Start-up' sec-
tion).
− The upper signal pressure range value
corresponds to the maximum value of the
bench range or operating range (when
the travel range is adapted, see 'Adapt-
ing the travel range' in the 'Start-up' sec-
tion).
a) Type 3271-5
Version with fail-safe action "actuator stem
extends" (FA)
Î Connect the signal pressure to the bottom
signal pressure connection (S). See
Fig. 5-1.
EB 8310-1 EN
The signal pressure is routed to the bot-
tom diaphragm chamber and moves the
actuator stem (A7) upward opposing the
spring force.
Î Screw the vent plug into the connection
on the top diaphragm case.
Version with fail-safe action "actuator stem
retracts" (FE)
Î Connect the signal pressure to the top
signal pressure connection (S).
The signal pressure is routed to the top
diaphragm chamber and moves the ac-
tuator stem (A7) downward opposing the
spring force.
Î Screw the vent plug into the connection
on the bottom diaphragm case.
b) Type 3277-5
Operation with positioner (switchover plate)
Î Turn the switchover plate to align the
symbol (A2.4) matching the fail-safe
action and attachment side with the
marking (A2.5). See Fig. 5-5.
Operation without positioner (connecting
plate)
Î Turn the connecting plate to align the
symbol (A2.4) matching the fail-safe
action with the marking (A2.5). See
Fig. 5-5.
Î Make sure that the gasket for the con-
necting plate is correctly inserted.
Î The connecting plate has threaded holes
with NPT and G threads. Seal the con-
nection that is not used with the rubber
seal and square plug.
Installation
5-7