Samson 3730-4 - Operation; Operator Controls and Readings

54 EB 8384-4 EN
Connections
The bench range is written on the nameplate
either as the spring range or signal pressure
range depending on the actuator. The direc-
tion of action is marked FA or FE, or by a
symbol.
Actuator stem extends FA (AIR TO OPEN)
Fail-close (for globe and angle valves):
Required supply pressure = Upper bench
range value + 0.2bar, at least 1.4bar.
Actuator stem retracts FE (AIR TO CLOSE)
Fail-open (for globe and angle valves):
For tight-closing valves, the maximum signal
pressure pst
max
is roughly estimated as fol-
lows:
pst
max
= F +
d² · π · ∆p
[bar]
4 · A
d = Seat diameter [cm]
∆p = Differential pressure across the valve [bar]
A = Actuator diaphragm area [cm²]
F = Upper bench range value of the actuator [bar]
If there are no specications, calculate as
follows:
Required supply pressure = Upper bench
range value + 1bar
5.1.3 Signal pressure (output)
The signal pressure at the output (38) of the
positioner can be restricted to 1.4bar,
2.4bar or 3.7bar in Code16.
The limitation is not activated [No] by de-
fault.
5.2 Electrical connections
Riskoffatalinjuryduetotheformationof
anexplosiveatmosphere.
The following regulations apply to installa-
tion in hazardous areas: EN60079-
14:2008 (VDE 0165, Part1) Explosive At-
mospheres– Electrical Installations Design,
Selection and Erection.
Incorrect electrical connection will render the
explosion protection unsafe.
Adhere to the terminal assignment.
Do not undo the enameled screws in or on
the housing.
Do not exceed the maximum permissible val-
ues specied in the EC type examination cer-
ticates when interconnecting intrinsically
safe electrical equipment (U
i
or U
0
, l
i
or I
0
, P
i
or P
0
, C
i
or C
0
and L
i
or L
0
).
Selecting cables and wires
Observe clause12 of EN60079-14: 2008
(VDE0165, Part1) for installation of the in-
trinsically safe circuits.
Clause12.2.2.7 applies when running multi-
core cables and wires with more than one
intrinsically safe circuit.
The radial thickness of the insulation of a
conductor for common insulating materials
(e.g. polyethylene) must not be smaller than
0.2mm. The diameter of an individual wire
in a ne-stranded conductor must not be
DANGER
!
WARNING
!