Samson 3767 Service manual

Electropneumatic Positioner
Type 3767
Fig. 2 · Type 3767Fig. 1 · Type 3767
Mounting and
Operating Instructions
EB 8355-2 EN
Edition April 2011

Contents Page
1 Design and principle of operation. . . . . . . . . . . . . . . . . . . . 4
1.1 Versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Attachment to control valve . . . . . . . . . . . . . . . . . . . . . . 10
2.1 Direct attachment to Type 3277 Actuator . . . . . . . . . . . . . . . . 10
2.2 Attachment according to IEC 60534-6 . . . . . . . . . . . . . . . . . 15
2.2.1 Mounting sequence . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.2 Presetting the travel . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3 Attachment to rotary actuators . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 Mounting the cam follower lever . . . . . . . . . . . . . . . . . . . . 20
2.3.2 Mounting the intermediate piece . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Default setting of the cam disk . . . . . . . . . . . . . . . . . . . . . 22
2.3.4 Reversing amplifier for double-acting actuators . . . . . . . . . . . . . 26
3 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1 Pneumatic connections. . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.1 Pressure gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.2 Supply pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.2.1 Switching amplifiers . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.1 Adjusting the positioner at the valve . . . . . . . . . . . . . . . . . . 32
4.1.1 Adjusting the proportional band Xp and air delivery Q . . . . . . . . . 33
4.1.2 Adjusting the actuator: "Actuator stem extends". . . . . . . . . . . . . 33
4.1.3 Adjusting the actuator: "Actuator stem retracts" . . . . . . . . . . . . . 34
4.2 Changing the operating direction . . . . . . . . . . . . . . . . . . . 35
4.3 Adjusting the limit switches. . . . . . . . . . . . . . . . . . . . . . . 36
4.4 Adjusting the position transmitter. . . . . . . . . . . . . . . . . . . . 38
5 Converting and retrofitting the positioner . . . . . . . . . . . . . . . 40
5.1 Converting from electropneumatic to pneumatic . . . . . . . . . . . . 40
5.2 Fitting limit switches . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.3 Fitting a solenoid valve . . . . . . . . . . . . . . . . . . . . . . . . 41
5.4 Removing the solenoid valve . . . . . . . . . . . . . . . . . . . . . . 42
6 Servicing explosion-protected versions. . . . . . . . . . . . . . . . . 42
7 Dimensions in mm. . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Test certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2EB 8355-2 EN
Contents

EB 8355-2 EN 3
Safety instructions
General safety instructions
4
The positioner may only be assembled, started up or operated by trained
and experienced personnel familiar with the product.
According to these mounting and operating instructions, trained personnel is
referred to as individuals who are able to judge the work they are assigned
to and recognize possible dangers due to their specialized training, their
knowledge and experience as well as their knowledge of the relevant stan-
dards.
4
Explosion-protected versions of this positioner may only be operated by per-
sonnel who have undergone special training or instructions or who are au-
thorized to work on explosion-protected devices in hazardous areas. Refer
to section 6 on Servicing explosion-protected versions.
4
Any hazards that could be caused by the process medium, the operating
pressure, the signal pressure or by moving parts of the control valve are to
be prevented by means of the appropriate measures. If inadmissible motions
or forces are produced in the actuator as a result of the supply pressure
level, it must be restricted by means of a suitable supply pressure reducing
station.
4
Proper shipping and appropriate storage are assumed.
4
Note: The device with a CE marking fulfils the requirements of the Directives
94/9/EC (ATEX) and 89/336/EEC (EMC).
The declaration of conformity is available on request.

1 Design and principle of
operation
The positioner consists of an electro-
pneumatic converter unit (i/p converter) and
a pneumatic unit equipped with a lever for
travel pick-up, a measuring diaphragm, and
the pneumatic control system with nozzle,
diaphragm lever (flapper plate) and booster.
The positioner is designed either for direct
attachment to SAMSON Type 3277 Actua-
tors or for attachment according to NAMUR
(IEC 60534-6) with an adapter housing.
The positioner can be additionally equipped
with either inductive limit switches and/or a
solenoid valve or a position transmitter.
The DC control signal, e.g. 4 to 20 mA, is-
sued by the control unit is transmitted to the
electropneumatic conversion unit (13) where
it is converted into a proportional pressure
signal pe.
The positioner operates according to the
force-balance principle. The valve travel, i.e.
the valve position, is transmitted to the
pick-up lever (1) over the pin (1.1) and de-
termines the force of the measuring spring
(4). This force is compared to the positioning
force generated by the pressure peat the
measuring diaphragm (5).
If either the control signal or the valve posi-
tion changes, the diaphragm lever (3)
moves, altering the distance to the nozzle
(2.1 or 2.2), depending on the set operating
direction of the positioner.
The air is supplied to the booster (10) and
the pressure regulator (9). The controlled
supply air is fed to the i/p module, then
flows through the Xprestriction (8) and the
nozzle (2.1, 2.2) to finally stream on the di-
aphragm lever (flapper plate). Any change
in the reference variable or the valve stem
position cause the pressure to change up-
stream or downstream of the booster. The
air controlled by the booster (signal pressure
pst) flows through the volume restriction (11)
to the pneumatic actuator, causing the plug
stem to move to a position corresponding to
the DC input signal (reference variable).
The adjustable Xprestriction (8) and volume
restriction (11) are used to optimize the
positioner control loop. The pick-up lever (1)
and the range spring (4) must be selected to
match the rated valve travel and the nominal
span of the reference variable.
Positioner with inductive limit switches
In this version, the rotary shaft of the
positioner carries two adjustable tags which
actuate the built-in proximity switches.
Positioner with solenoid valve
When the positioner is equipped with a so-
lenoid valve, the control valve can be moved
to the fail-safe position regardless of the
positioner's output signal. If a control signal
corresponding to the binary signal "0" (off)
is applied to the input, the signal pressure
pst is shut off and the actuator is vented. The
actuator springs move the control valve to its
fail-safe position. If a control signal corre-
sponding to the binary signal "1" (on) is ap-
plied to the input, the signal pressure pst is
supplied to the actuator. The control valve is
in control operation.
4EB 8355-2 EN
Design and principle of operation

EB 8355-2 EN 5
Design and principle of operation
43 7 8 911
6.1 6.2
13
789101112
6.1 46.2
2.1
3
2.2
5
1
1.1
1.2
Pe
Supply
9
V
Pst
Q
Xp
p
imA
13
Fig. 2 · Functional diagram and inside view
1 Pick-up lever
1.1 Pin
1.2 Clamp
2.1 Nozzle >>
2.2 Nozzle <>
3 Diaphragm lever
4 Range
spring
5 Measuring
diaphragm
6.1 Span adjuster
6.2 Zero adjuster
7 Turnboard
8 Xp restriction
9 Pressure regulator
10 Booster
11 Volume restriction
12 Solenoid valve
(optional)
13 i/p converter
Travel

Positioner with position transmitter
A positioner containing a position transmit-
ter cannot be equipped with integrated limit
switches or an integrated solenoid valve
since the position transmitter requires most
of the space inside. The position transmitter
is used to establish a certain relationship be-
tween the valve position, i.e. the valve travel,
and a controller output signal of 4 to 20
mA. The position transmitter setting ensures
that both end positions "valve CLOSED" or
"valve OPEN" as well as all intermediate
positions can be signalized. Since the valve
position is signalized independently of the
input signal to the positioner, the position
transmitter is a suitable option for checking
the current valve position.
6EB 8355-2 EN
Design and principle of operation

1.1 Versions
EB 8355-2 EN 7
Versions
Electropneumatic positioner Type 3767- x x x 0 1 xxxxxx000
Explosion protection
Without 0 2
II 2 G EEx ia IIC T6 acc. to ATEX 1
FM/CSA intrinsically safe/non incendive 3
II 3 G EEx nA II T6 acc. to ATEX 8
Additional equipment
Without 0
Limit switch, inductive, 2x SJ2-SN 2
Analog position transmitter, 4 to 20 mA* 6 0 0
3/2-way solenoid valve
Without 0
6 V DC 2
12 V DC 3
24 V DC 4
Type of mounting
Standard range spring 0 1
Pneumatic connections
¼-18 NPT 1
ISO 228/1 - G ¼ 2
Electrical connections
Cable gland
M20 x 1.5, blue (plastic) 1 0
M20 x 1.5, black (plastic) 2 0
M20 x 1.5 (nickel-plated brass) 2 1
Housing version
Die-cast aluminum 1
Stainless steel (CrNiMo) 2
Reference variable
4 … 20 mA 1
0 … 20 mA 2
1 … 5 mA 3
Temperature range
Standard 0
Low temperature
Tmin ³–45 °C; optional limit switches, solenoid valve 2 1 2
Special version
None 000
* Available until December 2011

1.2 Technical data
8EB 8355-2 EN
Technical data
Positioner
Travel range, adjustable
Opening angle
Direct attachment: 7.5 to 30 mm
Attachment acc. to IEC 60534-6: 7.5 to 120 mm or
Depending on the cam disk: 30 to 90°
Reference variable
Signal range
Span
Coil reference Riat 20 °C
4 (0) to 20 mA
8 to 20 mA
200 W
1 to 5 mA
2 to 4 mA
880 W
Supply air 1.4 to 6 bar (20 to 90 psi)
Air quality acc. to ISO 8573-1: Max. particle size and density: Class 4,
Oil content: Class 3, pressure dew point: Class 3
Signal pressure pst (output) Can be limited between approx. 2.5 to 6.0 bar (38 to 90 psi)
Characteristic Linear characteristic, deviation from terminal-based conformity £1 %
Hysteresis £0.3 %
Sensitivity £0.1 %
Operating direction Reversible
Proportional band Xp< 1 to 2.5 % (proportional-action coefficient Kp> 100 to 40)
Air consumption With supply air = 1.4 bar: £280 ln/h With supply air = 6 bar: £280 ln/h with
min. adjusted pressure regulator
Air delivery Actuator pressurized: 3.0 mn
3/h
Actuator vented: 4.5 mn
3/h 8.5 mn
3/h
14.0 mn
3/h
Permissible
ambient temperature
–20 to 80 °C with plastic cable gland
–40 to 80 °C with metal cable gland (special version down to –45 °C)
–20 to 70 °C for positioners with position transmitter
See attached certificate for explosion-protected devices
Influences Temperature: £0.3 %/10 K
Supply air: £1 % between 1.4 and 6 bar
Vibration: None between 10 and 150 Hz and 4 g
Explosion protection Type of protection EEx ia IIC T6, see attached certificate
Degree of protection IP 54 (upgradable to IP 65 using a filter check valve, see Accessories table)
Electromagnetic
compatibility Complying with requirements specified in EN 61000-6-2, EN 61000-6-3 and
NAMUR Recommendation NE 21
Weight Approx. 1 kg

EB 8355-2 EN 9
Technical data
Inductive limit switches
2 proximity switches Type SJ 2-SN
Control circuit Ratings according to downstream transistor relay
Hysteresis at rated travel £1 %
Solenoid valve
Input Binary direct current signal
Nominal signal 6 V DC 12 V DC 24 V DC
Signal 0 (no pick-up),
DC signal at –25 °C £1.2 V £2.4 V £4.7 V
Signal 1 (safe pick-up),
DC signal at 80 °C ³5.4 V ³9.6 V ³18 V
Maximum permissible signal 28 V 25 V 32 V
Coil resistance Riat 20 °C 2909 W5832 W11714 W
Air consumption in steady state In addition to that of the positioner: "Off" £60 ln/h · "On"£10 ln/h
Closing time with
Rated travel and
signal pressure
range
(KVS = 0.14)
Type 3277
Actuator 120 cm² 240 cm² 350/355 cm² 700 cm²
0.2 to 1 bar
£0.5 s
£1 s £1.5 s £4 s
0.4 to 2 bar £2 s £2.5 s £8 s
0.6 to 3 bar ££1 s £1.5 s £5 s
Position transmitter* – Intrinsically safe output current circuit
Output signal Two-wire circuit 4 to 20 mA, reversible operating direction
Power supply Min. terminal voltage 12 V DC, max.
45 V DC Only with intrinsically safe circuit
Performance Characteristic: output linear to input, deviation from characteristic £1 %
Hysteresis £0.6 %
Response £0.1 %
Influence of power supply £1 % when voltage changes occur within the specified limits
HF influence £0.1 %, f = 150 MHz, 1 W power output at a distance of 0.5 m
Load influence £0.1 %
Permissible ambient temperature –20 to 70 °C –20 to … Refer to certificate
Ambient temperature influence £0.4 % on lower measuring range value, ££0.2 % on measuring span
Ripple of output signal £0.3 %
* Data refer to standard spring (15 mm travel with Type 3277 Actuator) and gain of 100.

2 Attachment to control valve
The positioner is attached either directly to
SAMSON Type 3277 Actuator or to valves
with cast yokes or with rod-type yokes in ac-
cordance with IEC 60534-6 (NAMUR).
When combined with an intermediate piece,
the device can also be attached to rotary ac-
tuators as a rotary positioner. As the
positioner is also available as a basic unit
without accessory equipment, refer to the ta-
bles on the following pages for both the re-
quired mounting parts and their associated
order numbers.
Do not remove the protective cover on the
back of the positioner before actually start-
ing to attach the positioner.
Mounting position and operating direction
The operating direction of the positioner
also determines its mounting position on the
actuator as illustrated in Figs. 3, 4 and 6.
The turnboard (7, Fig. 2) at the positioner
must be mounted correspondingly. For an
increasing input signal (reference variable),
the signal pressure pst can either be increas-
ing (direct action >>) or decreasing (reverse
action <>). This also applies when the refer-
ence variable decreases: direct action >>
causes the signal pressure to decrease, re-
verse action <> causes the signal pressure to
increase.
On the turnboard (7), the operating direc-
tion is indicated by symbols (direct >>, re-
verse <>). Depending on the position of the
turnboard, the adjusted operating direction
and the associated symbol become visible.
If the required operating direction does not
correspond to the visible symbol, or if you
want to change the operating direction, re-
move the fastening screw at the turnboard,
turn the board by 180°, and refasten the
turnboard with the screw. Make sure the
three rubber gaskets inserted in the housing
remain in position.
Note: When any subsequent changes are
made, e.g. reversing the operating direction
of the positioner control loop or changing
the actuator from “Actuator stem extends” to
“Actuator stem retracts” or vice versa, the
positioner's mounting position must be
changed accordingly.
2.1 Direct attachment to Type
3277 Actuator
Required accessories are listed in Tables 1
to 4 on page 14.
The attachment of the positioner either on
the left or right side of the actuator (always
looking at the signal pressure connection or
switchover plate) is determined by the re-
quired operating direction of the positioner,
i.e. >> or <>.
10 EB 8355-2 EN
Attachment to control valve