Samson 3277-5 - Manual Mode (Versions with Handwheel Only); Additional Notes Concerning Operation

7-2 EB 8310-1 EN
Operation
Actuator stem retracts
With fail-safe action "actuator stem retracts",
the permissible supply pressure must not ex-
ceed the upper bench range value by more
than3bar:
Rated signal
range
Fail-safe
action
Max.
supply
pressure
0.2to1.0bar
Actuator stem
retracts
4bar
0.4to2.0bar 5bar
0.6to3.0bar 6bar
Actuator stem extends
With fail-safe action "actuator stem extends"
and travel stop, the supply pressure must not
exceed the upper signal range value by
more than 1.5 bar.
7.3 Manual mode (versions
with handwheel only)
In the manual mode, the valve is opened
and closed by the handwheel. The valve po-
sition is independent of the signal pressure
or actuator springs.
The handwheel must be in the neutral posi-
tion to allow the actuator to move through its
entire travel range in throttling or on/off ser-
vice.
7.4 Additional notes con-
cerning operation
Î Label actuators with reduced supply
pressure with a sticker ("Max. supply
pressure limited to ... bar").
Î Only apply the signal pressure to the sig-
nal pressure connection (S) on the dia-
phragm chamber of the actuator which
does not contain any springs (see
Fig.3-1inthe'Designandprincipleof
operation' section).
Î Only use vent plugs that let air through
them(A16inFig.3-1inthe'Designand
principle of operation' section).