Samson 3274 Service manual

Electrohydraulic Actuator
Type 3274
Mounting and
Operating Instructions
EB 8340 E
Edition June 2001
Fig. 1 ⋅Type 3274

Contents Page
Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1. Design and principle of operation . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Additional electric equipment . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Assembl of actuator and valve . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1 Manual operation of the actuator . . . . . . . . . . . . . . . . . . . . . . . 12
4.1.1 Version with electric override . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1.2 Version with manual override . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 djusting additional electric equipment . . . . . . . . . . . . . . . . . . . 14
4.2.1 Positioner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2.2 Position transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2.3 Potentiometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.4 Limit switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5. Dimensions in mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Contents
2EB 8340 EN

Safety instructions
Assembly, start-up and operation of the de ice may only be performed by
trained and experienced personnel familiar with this product.
According to these mounting and operating instructions, trained personnel
refers to indi iduals who are able to judge the work they are assigned to and
recognize possible hazards due to their specialized training, their knowledge
and experience as well as their knowledge of the applicable standards.
Any hazards which could be caused by the process medium, the signal press-
ure and mo ing parts of the control al e are to be pre ented by means of ap-
propriate measures.
Proper shipping and appropriate storage are assumed.
The actuators are designed for use in electrical power installations. For wiring
and maintenance, you are required to obser e the rele ant safety regulations.
Only use power interruption de ices which are protected against unintentional
reconnection of the power supply.
Take special care when making adjustments on li e parts. Do not remo e any
co ers!
EB 8340 EN 3

ctuator T pe 3274 -11 -12 -13 -14 -15 -16 -17 -18 -21 -22 -23
Manual override Electric Mechanical Electric
Fail-safe action Without With
Operating direction OUT IN OUT
Rated travel 15 or 30 mm
Nominal transit time

60 s for 15 mm, 120 s for 30 mm, depending on temperature and required thrust
Positioning rate for
fail-safe action mm/s

Standard
Optional
1
3.3
1
3.3
1.3
5
Thrust
N
Travel
15 mm When
stem
moves:
IN 2100 500 4300 500 2100 500 4300 500 2100 1800 500
OUT 2000 3400 4300 7700 2000 3400 4300 7700 2000 2300 3400
Travel
30 mm
IN 2100 500 4300 500 2100 500 4300 500 2100 1800 500
OUT 1800 3000 4300 7300 1800 3000 4300 7300 1800 2100 3000
Power suppl 230 V, 110 V and 24 V, 50 or 60 Hz (±10 %)
Power consumption Min. 80 VA / max. 155 VA

Permissible ambient temperature 10 to +60°C (with heating: 35 to +60 °C)
Permissible storage temperature 25 to +70 °C
Degree of protection IP 65
Weight 12 13 12
Motor electronics Radio interference level acc. to DIN VDE 0857
dditional electric equipment
Electric positioner Suppl same as power suppl
Control signal 4 to 20 mA, 0 to 20 mA (R
E
= 50 Ω), 0 to 10 V DC, 2 to 10 V DC (R
E
= 10 Ω)
Zero shift 0 to 100 %
Change of range 30 to 100 %
Output (feedback) 4 (0) to 20 mA, R = ≤200 Ω; 0 (2) to 10 V, R = ≤2 kΩ
H steresis Approx. 3 %
Potentiometer 0 to 1000 Ω, 0 to 200 Ω, 0 to 100 Ω, 0 to 275 Ω, 0 to 138 Ω
(for rated travel, 80 % of the final value); perm. load 0.5 W
Electric limit switch Maximum of three separatel adjustable double-throw contacts, max. 250 V AC, 5 A
Inductive limit switch Proximit switch SJ 2-N (normall closed contact onl )
Control circuit Rating according to the isolating switch amplifier used
Heating Approx. 45 W On: < 10 °C, off: > 0 °C above installed thermostats
Materials
Case, cover C linder Piston Piston rod Actuator stem H draulic oil
Die-cast aluminum H draulic
c linder tube
Steel/NBR
combination
C 45, hard
chromium plating 1.4104 Special HPL, silicone free

Other values on request

Depending on the version, up to 200 VA at high speeds and when heating is on
Technical data
4EB 8340 EN

1. Design and principle of operation
The electroh draulic actuators are espe-
ciall suitable for attachment to control
valves of the Series 240, 250 and 280, etc.
The actuators are connected to the valve
bonnet via ring nut. The actuator and plug
stem are tightl connected b a stem connec-
tor. The actuator essentiall consists of the
actuator housing, the motor including oil
pump as well as the c linder housing plus
piston.
Pilot valves control the suppl and dis-
charge of the compressed oil at the piston.
The actuator is equipped with compression
springs which determine the positioning
forces. Actuator versions with spring mech-
anism also serve to ensure the fail-safe posi-
tion of the valve in the operating direction
"Actuator stem retracts or extends" in case
the power suppl fails.
1.1 Versions
The following versions are available for dif-
ferent applications:
Versions with electric override
Type 3274-11 ⋅ Electroh draulic actuator
with a nominal thrust FIN of 2100 N for
operating direction "Actuator stem retracts"
and a nominal thrust FOUT of 1800 N for
operating direction "Actuator stem extends".
Type 3274-12 ⋅ Electroh draulic actuator
with FIN of 500 N and FOUT of 3000 N.
Type 3274-13 ⋅ Electroh draulic actuator
with FIN and FOUT of 4300 N each.
Type 3274-14 ⋅ Electroh draulic actuator
with FIN of 500 N and FOUT of 7300 N.
Versions with mechanical override
With these versions, the electric override is
replaced with a mechanical version.
Type 3274-15 ⋅ Electroh draulic actuator
with thrusts as for T pe 3274-11.
Type 3274-16 ⋅ Electroh draulic actuator
with thrusts as for T pe 3274-12.
Type 3274-17 ⋅ Electroh draulic actuator
with thrusts as for T pe 3274-13.
Type 3274-18 ⋅ Electroh draulic actuator
with thrusts as for T pe 3274-14.
Versions with fail-safe action and electric
override
Type 3274-21 ⋅ Electroh draulic actuator
with a nominal thrust FIN of 2100 N and
FOUT of 1800 N. Fail-safe action "Actuator
stem extends".
Type 3274-22 ⋅ Electroh draulic actuator
with a nominal thrust FIN of 1800 N and
FOUT of 2100 N. Fail-safe action "Actuator
stem retracts".
Type 3274-23 ⋅ Electroh draulic actuator
with a nominal thrust FIN of 500 N and
FOUT of 3000 N. Fail-safe action "Actuator
stem extends".
Typetesting
The T pe 3274-21 and 3247-23 Actuators
are t petested with different SAMSON
valves according to TÜV.
See name plate for the DIN register number.
EB 8340 EN 5
Design and rinci le of o eration

1.2 Principle of operation
The pressure-tight actuator housing (1, Fig.
2 on page 7) also serves as an oil reservoir
and incorporates the c linder housing (2),
c linder (5.1) and piston (5.2), motor (6.1),
pump (6.2) and solenoid pilot valves (6.4).
The motor (6.1) driven b the oil pump
(6.2) feeds compressed oil to the corre-
sponding c linder chamber via the check
valve (6.3) and pilot valve (6.4). In the de-
energized state, the solenoid valves are
closed. The open when the controller issues
a signal. When reaching final positions, or
external forces cause the nominal force of
the actuator to be exceeded, the motor is
deactivated.
Depending on the version, the actuators are
equipped with or without one or two com-
pression springs (5.7, 5.8). With T pes
3274-11, -12, -15, -16 and -21 to -23, the
motor moves the actuator stem in onl one
direction. The stem is then retracted b the
tension of the compression spring. Actua-
tors with electric override have two pushbut-
tons to open or close the valve.
Actuators with mechanical override are ad-
ditionall equipped with a gear case. An ex-
ternall mounted hexagon nut is used to
operate the mechanical override. The re-
lease button on the top of the actuator
serves to either open or close the control
valve.
Versions with fail-safe action are equipped
with a spring return mechanism and an ad-
ditional safet solenoid valve which opens
when the power suppl is interrupted, thus
reducing the oil pressure in the c linder
chamber. This mechanism moves the valve
plug to the fail-safe position. The operating
direction "Actuator stem extends or re-
tracts", depends on the spring arrangement
in the actuator.
1.3 dditional electric equipment
All additional electric equipment is located
in the terminal box (3). A rack-and-pinion
gear converts the linear travel of the actua-
tor stem into a rotar motion which is
picked off at the shaft to operate the switch-
ing and signaling elements. This additional
electric equipment can be retrofitted. The
maximum equipment configuration is
shown in the table "Additional equipment"
in section 4.2.
Electric positioners
Electric positioners compare the output sig-
nal of either 4(0) to 20 mA or 0(2) to 10 V
from an electric controller with the position
of a potentiometer (proportional to the
travel of the control valve) and produce a
three-point stepping signal.
Electric position transmitters
In the version with three-point stepping sig-
nal, an 0(4) to 20 mA or 0(2) to 10 V out-
put signal is generated proportional to the
travel of the valve using a 0 to 1000 Ω
potentiometer.
Potentiometers
The actuators can be equipped with two
potentiometers. A gear segment is driven b
a shaft. An easil adjustable transmission
mechanism including a twin pinion ensures
that the angle of rotation of 260° remains
the same for rated travels of 15 and 30 mm.
6EB 8340 EN
Design and rinci le of o eration

Electric limit switches
The actuators can be equipped with a maxi-
mum of three overrideable electric limit swit-
ches on request. The are actuated via infi-
nitel adjustable cams.
The motor is switched off with force-depend-
ent, fixed switches located in the actuator
case (1).
Actuators with spring return mechanism
onl contain one force-dependent switch,
since the springs (5.7 and 5.8) determine
the other end position.
Priority circuit
The positioner version is equipped with a
priorit circuit at terminals 82 and 83 (see
section 4.2.1).
Heating
For lower ambient temperature ranges, the
oil reservoir can be equipped with a heat-
ing b the manufacturer. It is activated via
thermostats when the oil temperature falls
below 10 °C and deactivated when the oil
reaches a temperature of > 0 °C.
The electrical connection is established via N
and L.
The heating is not protected b an internal
fuse.
Fig. 2 ⋅Functional diagram
Caution!
The case cover is secured b lead-
sealed screws.
All parts in the actuator case are
maintenance-free and must not be
adjusted.
Onl the manufacturer is authorized
to open the case.
1 Actuator case with oil reservoir
2Clinder housing
3 Electric terminal box
5.1 C linder
5.2 Piston
5.4 Coupling
5.6 Actuator stem
5.7 Compression spring
5.8 Compression spring
6.1 Motor
6.2 Gear pump
6.3 Check valve
6.4 Pilot valve
3
5.2
5.7
5.8
1
6.4
6.3
6.2
6.1
5.1
2
5.4
5.6
EB 8340 EN 7
Design and rinci le of o eration

2. Installation
Mounting position: To meet the mounting re-
quirements of actuators with heating
and/or manual override, the following
mounting positions should be observed.
The installation of the actuator also depends
on the mounting position of the control
valve used (see the associated mounting
and operating instructions).
For valve sizes DN 100 or above, install the
actuator verticall upright to facilitate an
maintenance required.
Alwa s observe minimum clearance for
removal of the connection cover or the com-
plete actuator (see dimensional drawings,
section 5).
2.1 ssembly of actuator and
control valve
If valve and actuator have not been preas-
sembled prior to deliver , proceed as fol-
lows (see Fig. 4):
Check whether actuator stem is retracted.
For versions with electric override: con-
nect actuator to power suppl (see sec-
tion 3). Disconnect isolating terminal 81
(see section 4.1) and use pushbutton IN to
start to retract the actuator stem.
For versions with mechanical override:
press button on the top of the actuator
case. Then use a hexagonal wrench to
operate the rack-and-pinion gear and
slowl retract the actuator stem.
For versions with fail-safe action "stem
extends", keep the power suppl to the
actuator connected, otherwise the fail-
safe function will extend the actuator
stem again.
Valve sizes DN 15 to 80 (Series 240)
1. Replace coupling nut (9.3) with an ex-
ternal Ø 10 mm located on the plug
stem with a Ø 16 mm nut (order no.
0250-0674).
2. After ou have replaced the nut (9.3),
adjust dimension x to 75 mm with the
valve closed, tighten lock nut (9.4).
3. Place the actuator on the valve bonnet,
thread it tight using the ring nut (8.1).
4. Push plug stem (9.5) upward, connect
coupling nut (9.3) and actuator stem b
means of the stem connector clamps
(8.2).
Fig. 3 ⋅Mounting position
permissible
not permissible
permissible
not permissible
8EB 8340 EN
Installation

5. Move valve to its end position, align
travel indicator scale (9.2) with the tip of
the stem connector.
Valve sizes DN 100 to 150 (Series 240,
250 and 280, Kvs 40 to160)
1. Check that dimension x = 90 mm, read-
just, if necessar , b turning the coup-
ling nut (9.3).
2. Place linear actuator on the valve bon-
net, secure tightl b using the ring nut
(8.1).
3. Connect coupling nut (9.3) and actua-
tor stem (5.6) using the stem connector
clamps (8.2), screw together tightl .
4. Move control valve to its end position,
align travel indicator scale (9.2) with tip
of the stem connector (8.2), screw tight.
Fig. 4 ⋅Actuator attachment
8 Actuator
8.1 Ring nut
5.6 Actuator stem
8.2 Stem connector clamp
9.1 Valve bonnet
9.2 Travel indicator scale
9.3 Coupling nut
9.4 Lock nut
9.5 Plug stem
8
8.1
5.6
8.2
9.3
9.4
9.2
9.5
9.1
x
EB 8340 EN 9
Installation

3. Electrical connections
Upon installation of the electric wir-
ing, you are required to obser e the
regulations go erning electrical
power plant installation according
to DIN VDE 0100 as well as the
regulations of your power supplier.
WARNING! Only connect to mains
when the power is switched off.
Use power interruption de ices
which ensure that the power cannot
be switched on again unintention-
ally.
Particularly for 24 V, 50 Hz actua-
tors, use wires with a sufficiently
large cross section in order to guar-
antee that the permissible oltage
tolerances of ±10 % are not ex-
ceeded.
Note:
When electrical connections are made as
described in the circuit diagrams, special
electronics in the motor ensure that the con-
tacts of controllers output relays (e.g. with
three-step controllers) are protected and
only a relati ely low power load is used.
A triac and a relay in the motor electronics
connect the power.
Remove the side case cover. Guide the
wires through the cable glands on the
case to the terminals and connect them
(see Figs. 5 to 7 or the circuit diagram in-
side the case cover).
Knock out the sealing plugs next to the exist-
ing cable entries, if required, to use two ad-
ditional cable entries.
Connect safet conductor to the separate
safet conductor terminal on the inside
case wall.
Electrical additional equipment
Connection diagrams 5 to 7 also appl to
the additional equipment.
Note that the limit switches must not be con-
nected to the terminal strip but to separate
screw terminals.
In the version with positioner (Fig. 6) and
position transmitter (Fig. 7), output signals
which are proportional to the valve travel
can be provided at the terminals 31, 32, 33
to be used for control and signaling pur-
poses (signal increases when the actuator
stem retracts).
Important: If any de ice is connected at the
oltage output, terminals 31 and 32 must
be jumpered.
Fuses
The board with the electronics section of the
motor contains a clamp with a 5 x 20 mm
glass-tube fuse which is used to protect the
actuator and the contacts of the external
controller when the actuator is wired as
shown in Figs. 5 to 7.
Suppl voltage
230 V, 50/60 Hz T1L 250 (1 A slow fuse),
Actuators with a transit time of 60 s/30 mm
travel:
230 V, 50 Hz T1.25, 250 (1.25 slow fuse)
110 V, 50 Hz T1.25 (1.25 A slow fuse)
24 V, 50 Hz T6.3 (6.3 A slow fuse)
10 EB 8340 EN
Electrical connections

Fig. 5 ⋅Circuit diagram for actuators with three-point stepping signal
Fig. 6 ⋅Circuit diagram for actuators with positioner
M
F
F
e
a
NLaL eL a43 e53 81
82 83 12 11 13 32 31 33 2.312.322.33
1
2
4
ae
"e" "a"
PE NL
-+-+
-+-+
3274-11...-18,-21,-23 3274-13,-14,-17,-18,-22
(0)4...20 mA (0)4...20 mA
(0)2...10V (0)2...10V
ϑ
Safet circuit,
onl for T pe 3274-2x
White
Green
Brown
Input
Control
signal
In Out
Priorit circuit
Output
(feedback)
Jumper for 0(2)...10 V
Feedback absolutel
necessar
Heating resistor
NLaL eL a43 e53 81 1.311.32 1.33 2.312.32 2.33
eaae
"e" "a"
1
2
4
M
F
F
e
a
PE NL
3274-11...-18,-21,-23 3274-13,-14,-17,-18,-22
ϑ
Controller
Safet circuit, onl for T pe 3274-2x
In Out
Heating resistor
C UTION!
The controller output rela used to control
the input signals aL and eL for the actuator
should onl be operated and connected
using the terminal 81 (same electric poten-
tial).
EB 8340 EN 11
Electrical connections

4. Operation
4.1 Manual operation of the actuator
4.1.1 Version with electric override
T pe 3274-11 to -14 and -22, -23
The actuator stem can be either retracted or
extended b pressing one of the two push-
buttons located on the side cover. In this
wa , the attached valve can be brought into
the required position.
fter releasing the button, the actuator
uses the controller signal again.
Important: If, e.g. upon start-up of the
plant, the control signal is to be interrupted
and the control al e is to remain in a cer-
tain position, the isolating terminal 81 must
be disconnected (Fig. 8).
For this purpose, proceed as follows:
1. Switch off power
2. Loosen the two fastening screws on the
side case cover and remove cover.
3. Place screwdriver under the release but-
ton of the isolating terminal 81 and
lever up button until it engages. The red
marking pin is not visible.
4. Reinstall cover with screws.
5. Switch on power.
Fig. 7 ⋅Circuit diagram for actuators with position transmitter
MF
F
e
a
NLaL eL a43 e53 81
82 83 12 11 13 32 31 33 2.312.322.33
1
2
4
ae
"e" "a"
PE NL
-+
-+
3274-11...-18,-21,-23 3274-13,-14,-17,-18,-22
(0)4...20 mA
(0)2...10V
ϑ
Safet circuit,
onl for T pe 3274-2x Output
In Out
Controller
Jumper for 0(2)...10 V
Feedback absolutel
necessar
Heating resistor
12 EB 8340 EN
O eration

The control signal is now interrupted and
the valve can be moved to the desired posi-
tion b using the two pushbuttons IN and
OUT. The valve will then remain in the ad-
justed position.
If the controller signal must have priorit
again, proceed as follows:
1. Switch off power. Remove case cover.
2. Firml press release button until it en-
gages so that the red marking pin
becomes visible.
3. Reattach case cover using screws,
switch on power.
Fig. 8 ⋅Terminal box with adjusting knobs
1
2
3
4
5
6
7
8
13
12
11
10
9
Release button
Red marking pin
Isolating terminal
Disconnect
isolating terminal
Connect isolating
terminal
1Fuse
2 Motor electronics
3 Adjuster for version
with positioner
4 Gear segment
5Push rod
6 Release button
7Marking pin
8Isolating terminal
9 Pushbutton OUT (extending)
10 Pushbutton IN (retracting)
11 Potentiometer
12 Limit switch
13 Switch block for version
with positioner
EB 8340 EN 13
O eration

4.1.2 Version with mechanical
override
1. Press black release button located on
the top of the actuator case.
2. Use a hexagonal wrench (SW 24) to
operate the rack-and-pinion gear at the
end of the shaft, projecting out of the
case, until ou have moved the valve to
the desired position.
As soon as the button is released, the actua-
tor operates according to the controller sig-
nal again.
If the valve is to remain in the manuall ad-
justed position, the isolating terminal 81
must be disconnected as described in sec-
tion 4.1.1.
4.2 djusting additional electric
equipment
The actuators can be equipped with differ-
ent combinations of additional electric
equipment. Such equipment can also be
retrofitted.
The maximum equipment configuration is
shown in the vertical columns of the table
below.
Table of additional electric equipment
Positioner ••
Position transmitter ••
Potentiometer 1 •

•

•

•

••••
Potentiometer 2 ••••••
Electric limit switch 1 ••
Electric limit switch 2 •••••
Electric limit switch 3 •••••
Inductive limit switch 1 •••••
Inductive limit switch 2 •••••

1000 Ω, required to transmit position for positioner/
position transmitter
4.2.1 Positioners
The actuator is controlled b a load-inde-
pendent DC current or DC voltage signal
which is used as reference variable w.
The valve travel must also be assigned to
this reference variable, normall a signal in
the range from 4 to 20 (0 to 20) mA or 2 to
10 (0 to 10) V, see Fig. 9.
In the split-range mode, the control valves
use smaller reference variables. The control-
ler output signal used to control two valves
is divided in such a wa that these valves
move through their entire travel range each
Fig. 9 ⋅Characteristics
100%
0%
4 20 mA12
420 mA
100%
0%
< > < <
< > < <
Actuator stem
retracted
Travel
Actuator stem
extended
Split-range mode
Valve 1 and 2
operating in
opposite directions
1 2
Reference variable
Dead band
14 EB 8340 EN
Adjusting additional electric equi ment

at half of the input signal range (for
example, first control valve adjusted to 12
to 4 mA and second control valve to 12 to
20 mA.
Note for split-range mode:
To pre ent the al es from o erlapping
when they are being adjusted, a dead band
as shown in Fig. 9, for example, ±0.5 mA
should be taken into account. Val e 1
would then be set from 11.5 to 4 mA and
Val e 2 from 12.5 to 20 mA, the corre-
sponding alues also apply for V input sig-
nals.
djusting knobs
The adjusting knobs (Fig. 10) are located
on the cover plate of the electronics unit. To
access them, unthread the two screws on
the side case cover and remove the cover.
C UTION! Device is energized!
The following functions can be selected at
the switch block SW b using the individual
switches SW 1 to 4.
Priority circuit  SW 1
If an external contact connected to terminals
82 and 83 is closed, the following function
results:
SW 1 set to ON  actuator stem retracts.
SW 1 set to OFF  actuator stem extends.
If the contact at terminals 82 and 83 is
open, the valve position is determined b
the controller signal again.
The mechanical fail-safe action is not af-
fected b the priorit circuit used in the actu-
ators.
Operating direction  SW 2
SW 2 set to ON <> actuator stem extends
when the reference variable increases.
SW 2 set to OFF >> actuator stem retracts
when the reference variable increases.
Output signal  SW 3 and 4
Depending on the signal connected to termi-
nals 31, 32 and 33
SW 3 and 4 set to ON  4 to 20 mA or 2
to 10 V
SW 3 and 4 set to OFF  0 to 20 mA or 0
to 10 V
Important: Both switches SW 3 and SW 4
must be in the same position!
Fig. 10 ⋅Adjusting knobs
on
off 1234
Zero Span Span
in out in
20
40 60 80
100
Switch SW
Final value
(range)
Start of operation
(zero)
Output signal
Feedback
EB 8340 EN 15
Adjusting additional electric equi ment

djustments at the valve
The following description refers to a globe
valve which closes when the actuator stem
extends and to a three-wa valve which pro-
vides tight closure of two ports.
The reference variable selected is 4 to
20 mA.
Pre-adjustments:
(required for both operating directions >>
and <> )
1. Open isolating terminal 81 b pulling
up the release button (Fig. 8).
2. Use the manual override to move the
control valve to the lower end position,
i.e. the actuator stem must be extended
as far as it will go in the valve seat.
With an electric override, press the +
button, with a mechanical override,
operate the rack-and-pinion gear (sec-
tions 3.1.1 and 3.1.2).
3. Turn the associated gear segment
around its axis according to the nomi-
nal travel of the control valve (15 or
30 mm) until the marking arrow is
above the point where the gears mesh
(Fig. 11).
4. Hold the gear segment and the gear in
this position. Then use a screwdriver to
turn the axis of the feedback poten-
tiometer P1 to the right as far as it will
go.
5. Select output signal for valve position in-
dication at the switches SW 3 and
SW 4.
6. Connect a suitable current or voltage
source (or controller) to the input signal
terminals (reference variable w).
Subsequentl connect an ammeter for
valve position indication to the termi-
nals 31, 32.
Operating direction >> :
7. Set switch SW 2 to OFF.
Turn Zero adjusting knob to the left as
far as it will go (0 %) and Spanin adjust-
ing knob to the mid position (mark).
8. Set input signal to the starting point
(4 mA) on the current source.
9. Slowl turn Zero adjusting knob clock-
wise until the LED turns off and then con-
tinue to turn it slightl until the LED
lights up again. This causes the maxi-
mum closing force to be produced in
the valve.
10. Use manual override to move the valve
to the upper end position, i.e. retract
the actuator stem.
Fig. 11 ⋅Tra el adjustment
15
30
P1 P2
Segment for 15 mm travel
Segment for 30 mm travel
Position of marking
arrow when push rod is
extended to the maximum
Potentiometer
Feedback potentiometer 0...1000 Ω for version
with positioner and position transmitter
16 EB 8340 EN
Adjusting additional electric equi ment

11. Set input signal at the current source to
the end value (20 mA).
12. Turn Spanout adjusting knob until the
ammeter indicates an output signal of
20 mA.
13. Turn Spanin adjusting knob all the wa
to the left. Then slowl turn back to the
right to the point where the LED just
turns off (when a globe valve is open).
Continue turning in the same direction
a little bit more until the LED lights up
again (when the second port of a three-
wa valve is closed) in order to produce
maximum closing forces.
14. If ou do not want to change the opera-
ting direction to <>, close isolating ter-
minal 81 b pressing the release button.
Operating direction <>
15. Set switch SW 2 to ON.
Turn Zero adjusting knob to the right as
far as it will go (100 %).
16. Set input signal to starting point 4 mA
again.
17. Slowl turn Zero adjusting knob to-
wards the left to the point where the
LED turns off (when a globe valve is
open). Then turn slightl in the same di-
rection until the LED just lights up again
(when the second port of a three-wa
valve is closed) in order tor produce
maximum closing forces.
Do not operate any other adjusting knob
after that!
18. Close isolating terminal 81 b pressing
the release button.
Note:
The positioner can also e used as a
"mere position transmitter".
To proceed, remo e the wires that lead
from the positioner case to the terminals aL
and eL and strip the insulation off the free
wire ends.
Then wire the wires of the external three-
point stepping signal (controller) to the ter-
minals aL, eL and 81.
The terminals 11, 12 and 13 as well as the
priority circuit no longer function.
4.2.2 Position transmitter
1. Select the output signal for position
transmitter at switch SW 3 and SW 4.
SW 3 and 4 to ON = 4 to 20 mA or 2
to 10 V
SW 3 and 4 to OFF = 0 to 20 mA or 0
to 10 V.
2. Connect an ammeter to terminals 31,
32 or after jumpering the terminals 32
and 31 connect a voltmeter to terminals
32 and 33 to indicate the valve position.
3. Move the valve to the lower end posi-
tion, i.e. the actuator stem must be ex-
tended as far it will go into the valve
seat using the manual override (section
4.1) or controller signal.
4. Turn the associated gear segment
around its axis according to the nomi-
nal travel of the control valve (15 or
30 mm) until the marking arrow is
above the point where the gears mesh
(Fig. 11).
5. Hold the gear segment and the gear in
this position. Then use a screwdriver to
turn the axis of the feedback poten-
EB 8340 EN 17
Adjusting additional electric equi ment

tiometer P1 to the right as far as it will
go.
6. Turn potentiometer P1 in the opposite
direction until the required intial value
of the output signal is indicated on the
measuring instrument.
7. Open the control valve, the final value
of the output signal should be indicated
on the measuring instrument. If the
value is incorrect, readjust the final
value correspondingl at the Spanout
adjusting knob.
The feedback signal increases as the ac-
tuator stem retracts.
If a signal with decreasing charac-
teristic is required, reverse the white
and green connecting wires at the
potentiometer.
4.2.3 Potentiometers
The actuator can be equipped with either
one or two potentiometers (Fig. 11), de-
pending on its version. Actuators equipped
with a positioner require a potentiometer
(P1) for internal valve position feedback. Its
resistance value cannot be used for external
signaling purposes.
Potentiometer P1:
1. Extend actuator stem all the wa into
the valve.
2. Depending on the nominal travel of the
valve, turn gear segment 15 or 30 mm
on its axis until the marking arrow is
above the point where the gears mesh
(Fig. 11).
3. Hold gear segment and gear in this po-
sition. Then use a screwdriver to turn
the axis of the potentiometer P1 all the
wa to the right.
Potentiometer P2:
This potentiometer is driven b the pinion of
potentiometer P1. Opposed resistance
values arise.
Adjust potentiometer as described for P1,
however, turn axis to the left as far as it will
go while holding the gear segment and the
gear.
4.2.4 Limit switches
The switching point of the additional limit
switches (Fig. 12) is infinitel adjustable
within the travel range.
Electric limit switches:
Move control valve to the desired switch-
ing position, turn adjustment screw until
the operating cam contacts the roller
and reverses the microswitch. If necess-
ar , move actuator in opposite direction,
check whether the cam reaches the
switching point at the desired switching
position.

Inductive limit switches:
When using inductive contacts, isolating
switch amplifiers must be connected in the
output circuit according to EN 50 227.
Move control valve to the desired switch-
ing position. Turn adjustment screw until
the metal tag triggers the contact.
18 EB 8340 EN
Adjusting additional electric equi ment

5. Dimensions in mm
Fig. 12 ⋅Electric (left) and inducti e (right) limit switches
Operating cam Roller Switch (covered) Metal tag Proximit switch
Clamping screw
Adjustment screw
Adjustment screw
.
.
.
.
T pe 3274-... Actuator with
mechanical override T pe 3274-... Actuator with electric override
75 for 15 mm travel 90 for 30 mm travel
75 for 15 mm travel
EB 8340 EN 19
Dimensions in mm

SAMSON AG ⋅ MESS- UND REGELTECHNIK
Weismüllerstraße 3 ⋅ 60314 Frankfurt am Main ⋅ German
Phone: [phone] ⋅ Fax: [phone]
Internet: http://www.samson.de
S/Z 2008-07
EB 8340 EN