Samson Type 3766 Service manual

Pneumatic Positioner
Type 3766
Mounting and
Operating Instructions
EB 8355-1 E
Edition September 2009
Fig. 1 ⋅Type 3766

Contents
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 Act ator . . . . . . . . . . . . . . . . . . . 10
2.2 Attachment according to IEC 60534-6 . . . . . . . . . . . . . . . . . . . . 15
2.2.1 Mo nting seq ence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.2 Presetting the travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3 Attachment to rotary act ators . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 Mo nting the cam follower lever . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.2 Mo nting the intermediate piece . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Defa lt setting of the cam disk . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.4 Reversing amplifier for do ble-acting act ators . . . . . . . . . . . . . . . . 26
3 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1 Pne matic connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.1 Press re ga ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.2 S pply press re . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.2.1 Switching amplifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4Operation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.1 Adj sting the positioner at the valve . . . . . . . . . . . . . . . . . . . . . 31
4.1.1 Adj sting the proportional band Xp and air delivery Q . . . . . . . . . . . . 32
4.1.2 Adj sting the act ator: "Act ator stem extends" . . . . . . . . . . . . . . . . 32
4.1.3 Adj sting the act ator: "Act ator stem retracts" . . . . . . . . . . . . . . . . 33
4.2 Changing the operating direction . . . . . . . . . . . . . . . . . . . . . . . 34
4.3 Adj sting the limit switches . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.4 Adj sting the position transmitter . . . . . . . . . . . . . . . . . . . . . . . 37
5 Converting and retrofitting the positioner . . . . . . . . . . . . . . . . . . 39
6 Dimensions in mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Test c er tificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2EB 8355-1 EN

Note!
Positioners with model index 3766-x...x. 03 and higher are equipped with a hinged co er
without ent connection. The required exhaust air connection is now included in the mount-
ing accessories. If these positioners are mounted on older actuator models, make absolutely
sure that there is a ent connection. If necessary, replace the mounting accessories as well.
Safety instructions
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 indi iduals who are able to judge the work they are assigned to
and recognize possible dangers due to their specialized training, their knowl-
edge and experience as well as their knowledge of the applicable standards.
Explosion-protected ersions of this positioner may only be operated by per-
sonnel who ha e undergone special training or instructions or who are auth-
orized to work on explosion-protected de ices in hazardous areas.
Any hazards that could be caused in the positioner by the process medium,
the operating pressure, the signal pressure or by mo ing parts are to be
pre ented by means of the appropriate measures.
If inadmissible motions or forces are produced in the pneumatic actuator as a
result of the supply air pressure le el, it must be restricted by means of a suit-
able supply pressure reducing station.
Proper shipping and appropriate storage are assumed.
Note! Positioners with a CE marking fulfill the requirements of the directi es
94/9/EC (ATEX) and 89/336/EEC (EMC). The declaration of conformity can
be iewed and downloaded on the Internet at http://www.samson.de.
EB 8355-1 EN 3

1 Design and principle of operation
The pne matic positioner is sed to ens re
a preselected assignment between the valve
stem position (controlled variable) and the
control signal (reference variable). In this
process, the o tp t signal from a control de-
vice is compared to the travel of the control
valve and a pne matic signal press re (o t-
p t variable) is s pplied to the act ator.
The positioner consists of the lever for travel
pick- p, the meas ring diaphragm, and the
pne matic control system comprising the
nozzle, diaphragm lever (flapper plate),
and the booster.
The positioner is designed either for direct
attachment to SAMSON Type 3277 Act a-
tors or for attachment according to NAMUR
(IEC 60534-6).
The positioner can additionally be eq ipped
with either ind ctive limit switches and/or a
solenoid valve or a position transmitter.
The positioner operates according to the
force-balance principle. The travel, i.e. the
valve position, is transmitted to the pick- p
lever (1) over the pin (1.1), determining the
force of the range spring (4).
This force is compared to the force gener-
ated by the press re pe at the meas ring
diaphragm (5).
If either the control signal or the valve posi-
tion changes, the diaphragm lever (3)
moves, alterating the distance to the
nozzle (2.1 or 2.2) depending on the set
operating direction.
The air is s pplied to the booster (10) and
the press re reg lator (9). The controlled
s pply air flows thro gh the Xp restric-
tion (8) and the nozzle (2.1, 2.2) against
the diaphragm lever (flapper plate).
Any change of the reference variable or the
valve stem position ca se the press re to
change pstream or downstream of the
booster.
The air controlled by the booster (signal
press re pst) flows thro gh the vol me re-
striction (11) to the pne matic act ator,
ca sing the pl g stem to move to a position
corresponding to the reference variable.
The adj stable restrictions Xp (8) and
Q (11) are sed to optimize the positioner
control loop.
The pick- p lever (1) and range spring (4)
m st be selected to match the rated valve
travel and the nominal span of the refer-
ence variable.
Positioner ith inductive limit s itches
In this version, the rotary shaft of the posi-
tioner carries two adj stable tags which ac-
t ate the b ilt-in proximity switches.
Positioner ith solenoid valve
When the positioner is eq ipped with a sole-
noid valve, the control valve can be moved
to its fail-safe position regardless of the posi-
tioners o tp t signal. If a control signal
corresponding to the binary signal "0" (off)
is applied to the inp t, the signal press-
re pst is sh t off and the act ator is vented.
The act ator springs move the control valve
to its fail-safe position.
If a control signal corresponding to the bi-
nary signal "1" (on) is applied to the inp t,
the signal press re pst is s pplied to the ac-
t ator. The control valve is in control oper-
ation.
4EB 8355-1 EN
Design and principle of operation

Fig. 2 ⋅Functional diagram and inside iew
789101112
6.1 46.2
2.1
3
2.2
5
1
1.1 1.2
P
e
Supply
9
V
P
st
Q
Xp
e
p
Travel
4 3 7 8 9 11
6.1 6.2
6.1 Span adj ster
6.2 Zero adj ster
7Trnboard
8X

restriction
9Pressre reglator
10 Booster
11 Vol me restriction
12 Solenoid valve (optional)
1Pick-p lever
1.1 Pin
1.2 Clamp
2.1 Nozzle >>
2.2 Nozzle <>
3 Diaphragm lever
4Range spring
5 Meas ring diaphragm
EB 8355-1 EN 5
Design and principle of operation

Positioner ith position transmitter
A positioner containing a position transmit-
ter cannot be eq ipped with integrated limit
switches or an integrated solenoid valve
since the position transmitter req ires most
of the space inside.
The position transmitter is sed to ens re a
preselected relationship between valve posi-
tion, i.e. valve travel, and a controller o t-
p t c rrent signal of 4 to 20 mA.
The position transmitter setting allows both
valve end positions valve CLOSED or
valve OPEN as well as all intermediate po-
sitions to be indicated. Since the valve posi-
tion is always indicated regardless of the po-
sitioners inp t signal, the position transmit-
ter is a s itable device to check the c rrent
valve position.
EB 8355-1 EN
Design and principle of operation

1.1 Versions
Pneumatic Positioner Type 3766- x x x 0 1 xxxx1x000
Explosion protection
Witho t 0 2
II 2 G EEx ia IIC T6 acc. to ATEX 1
FM/CSA intrinsically safe /non incendive 3
Ex ia / Ex n I/IIC T6 IP 65 IECEx TSA A stralia 6
II 3 G EEx nA II T6 acc. to ATEX 8
Additional eq ipment
Witho t 0
Limit switch, ind ctive, 2x SJ2 SN 2
Analog position transmitter 4 ... 20 mA 6 0 0
3/2-way solenoid valve
Witho t 0
6 V DC 2
12 V DC 3
24 V DC 4
Pne matic connections

⁄

−

NPT 1
ISO 228/1 - G

⁄

2
Electrical connections
Witho t (witho t additional eq ipment or solenoid valve) 0 0 0 0
Cable gland
M20 x 1.5 bl e (plastic) 1 0 0
M20 x 1.5 black (plastic) 2 0 0
M 20 x 1.5 (nickel-plated brass) 2 1 3
Ho sing version
Al min m die-cast 0
Stainless steel (CrNiMo) 2
Temperat re range
Standard 0
Low temperat re
T

≥ −50 °C; optional limit switches, solenoid valve 2 1 3
Special version
None 000
Device f nctioning only as analog position transmitter 3766- x 60000xxx00000
EB 8355-1 EN 7
Versions

1.2 Technical data
Positioner
Travel range, adj stable
Opening angle
Direct attachment: 7.5 to 30 mm,
Attachment according to IEC 60534-6: 7.5 to 120 mm
Depending on the type of cam disk: 30 to 90°
Reference variable
Signal range
Span
Max. overload limit
0.2 to 1bar (3 to 15 psi)
0.4 to 0.8 bar (6 to 12 psi)
2 bar (29 psi)
S pply press re 1.4 to 6 bar (20 to 90 psi)
Signal press re p

(o tp t) Can be limited between approx. 2.5 to 6.0 bar (38 to 90 psi)
Characteristic Linear
Deviation from terminal-based conformity
≤1%
Hysteresis ≤0.3 %
Sensitivity ≤0.1 %
Operating direction Reversible
Proportional band X

<1 to 2.5 % (proportional-action coefficient Kp: >100 to 40)
Air cons mption At 1.4 bar s pply press re
≤230 l

/h
At 6 bar s pply press re
≤230 l

/h with min. adj sted press. reg lator
Air delivery Filling the act ator: 3.0 m

/h
Venting the act ator: 4.5 m

/h
8.5 m

/h
14.0 m

/h
Permissible ambient
temperat re
20 °C to +80 °C with plastic cable gland; 40 °C to +80 °C with metal cable gland
(special version down to 45 °C available)
Positioner with position transmitter only 20 to 70 °C,
See attached inspection certificates for explosion-protected versions
Infl ences Temperat re: ≤0.3 %/10 K S pply press re:
≤1 % between 1.4 and 6 bar
Vibration: none from 10 to 150 Hz and 4 g
Explosion protection Type of protection EEx ia IIC T6 (see attached inspection certificate)
Degree of protection IP 54 (IP 65 by sing a filter check valve, see Accessories table)
Electromagnetic
compatibility
Req irements according to EN 61000-6-2, EN 61000-6-3,
and NAMUR Recommendation 21 are f lfilled
Weight Approx. 1 kg
Inductive limit s itches
2 proximity switches Type SJ 2-SN
Control circ it Ratings according to downstream transistor relay
Hysteresis at rated travel ≤1 %
8EB 8355-1 EN
Technical data

Solenoid valve
Inp t Binary direct c rrent signal
Nominal signal 6 V DC 12 V DC 24 V DC
Signal 0 (no pick- p) , DC signal at 25 °C ≤1.2 V ≤2.4 V ≤4.7 V
Signal 1 (safe pick- p), DC signal at +80 °C ≥5.4 V ≥9.6 V ≥18 V
Max. permissible signal 28 V 25 V 32 V
Coil rsistance R

at 20 °C 2909 Ω5832 Ω11714 Ω
Air cons mption in steady state, K

= 0.14 m

/h In addition to that of the positioner: "Off"
≤60 l

/h; "On" ≤10 l

/h
Closing time for
For rated travel and
signal press re
range
Type 3277 Act ator cm

120 240 350 700
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  Instrinsically safe o tp t c rrent circ it
O tp t signal Two-wire system 4 to 20 mA, reversible operating direction
Permissible load U

 12 V
R

= 
20 mA
Power s pply Voltage range 12 to 45 V DC Only with intrinsically safe c rrent circ it
Characteristic O tp t linear to inp t, deviation from characteristic
≤1 %
Hysteresis ≤0.6 %
Response span ≤0.1 %
Power s pply infl ence ≤1 % when voltage changes within the specified limits
HF infl ence ≤0.1 %, f = 150 MHz, 1 W transmitter power at a distance of 0.5 m
Load infl ence ≤0.1 %
Permissible ambient temperat re 20 to +70 °C 20 to ... See declaration of conformity
Ambient temperat re infl ence ≤0.4 % on lower meas ring range limit,
≤0.2 % on meas ring span
Ripple of o tp t signal ≤0.3 %
Data refer to standard spring (15 mm travel with Type 3277 Act ator) and gain of 100
EB 8355-1 EN 9
Technical data

2 Attachment to control valve
The positioner can be attached either di-
rectly to a SAMSON Type 3277 Act ator
or to valves with cast yokes or rod-type
yokes according to IEC 60534-6 (NAMUR).
When combined with an intermediate
piece, the device can also be attached to
rotary act ators as a rotary positioner.
As the positioner is also available as a
basic nit witho t accessory eq ipment,
refer to the tables on the following pages
for both the req ired mo nting parts and
their associated order n mbers.
Do not remove the protective cover on the
positioners rear side before act ally start-
ing to attach the positioner.
Mounting position and operating direction
The operating direction of the positioner
also determines its mo nting position on the
act ator as ill strated in Figs. 3, 4, and 6.
The t rnboard (7, Fig. 2) at the positioner
m st be mo nted correspondingly.
For an increasing inp t signal (reference
variable), the signal press re pst can either
be increasing (direct action >>) or decreas-
ing (reverse action <>).
This also applies when the reference vari-
able decreases: direct action >> ca ses the
signal press re to decrease, reverse ac-
tion <> ca ses the signal press re to in-
crease.
On the t rnboard (7), the operating direc-
tion is indicated by symbols (direct >>,
reverse <>).
Depending on the position of the t rnboard,
the adj sted operating direction and the as-
sociated symbol become visible.
If the req ired operating direction does not
correspond to the visible symbol, or if yo
want to change the operating direction,
remove the fastening screw at the t rn-
board, t rn the board by 180°, and re-
fasten the t rnboard with the screw. Make
s re the three r bber gaskets inserted in the
ho sing remain in position.
Important!
When any subsequent changes are made,
e.g. re ersing the operating direction of the
positioner control loop or changing the actu-
ator from Actuator stem extends to Actu-
ator stem retracts or ice ersa, the posi-
tioner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 act ator (always
looking at the signal press re connection or
switchover plate) is determined by the re-
q ired operating direction of the positioner,
i.e. >> or <>.
10 EB 8355-1 EN
Attachment to control valve