Samson 3785 series, Монтаж и эксплуатация

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2.3.4 Reversing amplifier for
double-acting actuators
For the use with double-acting actuators,
the positioner must be fitted with a revers-
ing amplifier.
The reversing amplifier is listed as an acces-
sory in the Table 6 on page 21.
The output signal pressure of the positioner
is supplied at the output A
1
of the reversing
amplifier. An opposing pressure, which
equals the required supply pressure when
added to the pressure at A
1,
is applied at
output A
2
. The rule A
1
+ A
2
= Z applies.
Mounting
1. Screw the special nuts (1.3) from the ac-
cessories of the reversing amplifier into
the threaded connections of the posi-
tioner.
2. Remove the sealing plug (1.5) from the
reversing amplifier. The rubber seal
(1.4) must remain installed.
3. Insert the gasket (1.2) into the recess of
the reversing amplifier and push both
the hollowed special screws (1.1) into
the connecting boreholes A1 and Z.
4. Place the reversing amplifier onto the
positioner and screw tight using both
the special screws (1.1).
5. Replace the venting plug in the revers-
ing amplifier with the filter check valve
included.
Signal pressure connections
A
1
: Output A
1
leading to the signal press-
ure connection at the actuator which opens
the valve when the pressure increases
A
2
: Output A
2
leading to the signal press-
ure connection at the actuator which closes
the valve when the pressure increases
Enter the actuator as "Double-acting
without spring-return mechanism" in the
user interface under Start-up
→
Actuator
type.
2.4 Fail-safe position of the
actuator
NOTE
If the fail-safe position of the actuator is
changed subsequently by modifying the ac-
tuator springs from "Actuator stem extends"
to "Actuator stem retracts", the mechanical
zero must be readjusted and the positioner
must be re-initialized.
22
EB 8382-1 EN
Reversing amplifier for double-acting actuators