Samson Type 3766, Mounting And Operating Instructions

Page: 26 / 52

2.3.4 Reversing amplifier for
double-acting actuators
When used with double-acting actuators,
the positioner must be equipped with a re-
versing amplifier.
The reversing amplifier is listed as an acces-
sory in Table 7 on page 19.
The output signal pressure of the positioner
is supplied at output A
1
of the reversing am-
plifier. An opposing pressure, which equals
the required supply pressure when added to
the pressure at A
1
, is supplied at output A
2
.
A
1
+ A
2
= Z applies.
On using the reversing amplifier, it is im-
portant to make sure that the adjuster of the
pressure regulator (9 in Fig. 2) is turned as
far as it will go in the clockwise direction.
Refer also to section 3.1.2).
Assembly
Important!
Remove the sealing plug (1.5) before install-
ing the reversing amplifier. The rubber
seal (1.4) must remain installed.
1. Screw the special nuts (1.3) included in
the accessories of the reversing ampli-
fier into the threaded connections of the
positioner.
2. Insert the gasket (1.2) into the recess of
the reversing amplifier and push the
two hollowed special screws (1.1) into
the connecting bore holes A1 and Z.
3. Place the reversing amplifier onto the
positioner and screw tight using the two
special screws (1.1).
Signal pressure connections
A
1
: Connect output A
1
to the signal press-
ure connection on the actuator that opens
the valve when the pressure increases.
A
2
: Connect output A
2
to the signal press-
ure connection on the actuator that closes
the valve when the pressure increases.
26
EB 8355-1 EN
Reversing amplifier for double-acting actuators