Samson 373 Series User Manual

20 EB 8384-2 EN
Design and principle of operation
The valve position is transmitted as a either
an angle of rotation or travel to the pick-up
lever and to the travel sensor (2) and supplied
toananalogPDcontroller.AnA/Dconverter
(4) transmits the position of the valve to the
microcontroller (5). The PD controller com
-
paresthisactualpositiontothe4to20mA
DC control signal (reference variable) after it
hasbeenconvertedbytheA/Dconverter(4).
In case of a set point deviation, the activation
ofthei/pconverter(6)ischangedsothatthe
actuator of the control valve (1) is pressurized
or vented accordingly over the downstream
booster (7). As a result, the closure member
of the valve (e.g. plug) is moved to the posi
-
tion determined by the set point.
The supply air is supplied to the booster (7)
and the pressure regulator (8). An intermedi-
ateowregulator(9)withxedsettingsis
used to purge the positioner and, at the same
time, guarantees trouble-free operation of the
booster. The output signal pressure supplied
by the booster can be limited by software.
The volume restriction Q (10) is used to opti
-
mize the positioner.
TheextendedEXPERTplusdiagnosticsarein-
tegrated into the positioner. They provide in-
formation on the positioner and generate di-
agnostic and status messages, which allow
faults to be pinpointed quickly.
3.1 Mounting versions
The positioner is suitable for the following
types of attachment using the corresponding
accessories(seesection3.4):
− Direct attachment to SAMSON
Type3277 Actuator
Î Seesection5.3.
− Attachment to actuators according to
IEC60534-6:
Î Seesection5.4.
− Attachment according to VDI/
VDE3847-1/-2:
Î Seesection5.5andsection5.6.
− Attachment to Type3510 Micro-ow
Valve
Î Seesection5.7.
− Attachment to rotary actuators accord-
ing to VDI/VDE3845:
Î Seesection5.8.
3.2 Additional equipment
Solenoid valve
If the operating voltage for the solenoid
valve (12) fails, the signal pressure for the
booster is vented to the atmosphere. As a re-
sult, the actuator is vented and the valve
moves to its fail-safe position.
The manual set point is automatically reset to
0% after the solenoid valve is activated.
A different manual set point must be entered
again (Code 1).
Position transmitter
The position transmitter (13) is a two-wire
transmitter and issues the travel sensor signal
NOTICE
!

Samson 373 Series Specifications

General

Brand	Samson
Model	373 Series
Category	Valve Positioners
Language	English