Samson 3730-0 - Operating the Positioner; Setting Zero; Activate Tight-Closing Function

54 EB 8384-0 EN
Operating the positioner
7 Operating the positioner
7.1 Setting zero
Before setting zero, settings using switches
S1 to S5 as well as switches S7 and S8 must
be made rst (see section5.10).
Î Set SPAN adjuster to 0.
Î Adjust the input signal according to the
table below using an ammeter.
Î Turn ZERO adjuster until the plug stem
just starts to move from its initial position.
Direction of
action
Set
point[mA]
Input signal for
zero [mA]
> > 4 to 20 4
> > 4 to 12 4
> > 12 to 20 12
< > 4 to 20 20
< > 4 to 12 12
< > 12 to 20 20
7.2 Reducing gain
Î Move the valve in small steps. If the valve
tends to hunt, set switch S6 to ON to re-
duce the gain of the control loop.
7.3 Adapting the travel
In case the rated travel of the control valve
does not correspond with the selected travel
according to the table in section 5.10.3:
Î Adjust the upper range value of the input
signal(e.g.4,12or20mA)usingthe
ammeter.
Î Turn the SPAN adjuster until the plug
stem moves as far as it will go to the end
position.
7.4 Activate tight-closing
function
Havingadjustedzeroandspan,the
tight-closing function (description on
page13)mustbeactivatedatswitchesS9
and S10 to ensure a tight valve shut-off.
AIR TO OPEN S9:ON S10: OFF
AIR TO CLOSE S9:OFF S10: ON
Three-way valve S9:ON S10: ON
Tight-closing func-
tion deactivated
S9:OFF S10: OFF
NOTICE
!