Samson TROVIS SAFE 3731-3, Mounting And Operating Instructions

Page: 29 / 104

4.5 Reversing amplifier for
double-acting actuators
For the use with double-acting actuators, the
positioner must be fitted with a reversing
amplifier, e.g. the SAMSON Type 3710 Re-
versing Amplifier (see Mounting and Oper-
ating Instructions EB 8392 EN).
If a different reversing amplifier (item no.
1079-1118 or 1079-1119) is used, follow
the mounting instructions described in sec-
tion 4.5.1.
The following applies to all reversing am-
plifiers:
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.
A
1
: Output
A
1
leading to the signal pressure
connection at the actuator which opens the
valve when the pressure increases
A
2
: Output
A
2
leading to the signal pressure
connection at the actuator which closes the
valve when the pressure increases
4.5.1 Reversing amplifier
(1079-1118 or 1079-1119)
NOTICE
Do not unscrew sealing plug (1.5) out of the
reversing amplifier.
1. Thread the special nuts (1.3) from the
accessories of the reversing amplifier
into the boreholes of the positioner.
Remove the rubber seal (1.4).
2. 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
A
1
and
Z
.
3. Position the reversing amplifier (1) and
screw tight using both the special
screws (1.1).
4. Use a screwdriver (8 mm wide) to
screw the enclosed filters (1.6) into the
connecting boreholes
A
1
and
Z
.
NOTICE
On start up of double-acting actuators, the
following settings as described in section 7
must be made:
– Pressure limit (Code 16 ) = No
– Fail-safe position (Code
0
) =
AtO
(AIR
TO OPEN)
Pressure gauge attachment
The mounting sequence shown in Fig. 10 re-
mains unchanged. Screw a pressure gauge
bracket onto the connections
A
1
and
Z
.
Pressure gauge G ¼ 1400-7106
bracket: ¼ NPT 1400-7107
Pressure gauges for supply air Z and output
A
1
as listed in Tables 1 to 4.
EB 8387-3S EN
29
Attachment to the control valve – Mounting parts and accessories