Samson 3725 series Service manual

Series 3725
Electropneumatic Positioner
Type 3725
Mounting and
Operating Instructions
EB 8394 EN (1300-1621)
Firmware version 1.0x
Edition February 2012
Fig. 1 · Type 3725 Positioner

2EB 8394 EN
WARNING!
indicates a hazardous situation which, if not
avoided, could result in death or serious
injury.
NOTICE
indicates a property damage message.
Note: Supplementary explanations,
information and tips
Definitions of the signal words used in these instructions

Contents Page
1 Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Article code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Design and principle of operation. . . . . . . . . . . . . . . . . . . . 8
3.1 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4 Attachment to the control valve – Mounting parts and accessories . . . 12
4.1 Direct attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1.1 Type 3277-5 Actuator . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1.2 Type 3277 Actuator . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 Attachment according to IEC 60534-6 . . . . . . . . . . . . . . . . . 20
4.3 Attachment to Type 3372 Actuator (V2001) . . . . . . . . . . . . . . 23
4.4 Attachment to rotary actuators . . . . . . . . . . . . . . . . . . . . . 24
4.5 Mounting parts and accessories . . . . . . . . . . . . . . . . . . . . 26
5 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1 Pneumatic connections . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1.1 Signal pressure gauges . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1.2 Supply pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.2 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . 29
6 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.1 Operator controls . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7 Start-up – Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.1 Enabling configuration. . . . . . . . . . . . . . . . . . . . . . . . . 34
7.2 Setting the volume restriction Q . . . . . . . . . . . . . . . . . . . . 35
7.3 Adapting the display. . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.4 Entering the opening direction . . . . . . . . . . . . . . . . . . . . . 36
7.5 Defining the direction of action. . . . . . . . . . . . . . . . . . . . . 36
7.6 Limiting the signal pressure. . . . . . . . . . . . . . . . . . . . . . . 36
7.7 Setting other parameters . . . . . . . . . . . . . . . . . . . . . . . 37
7.8 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.9 Zero calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.10 Manual mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
7.11 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
EB 8394 EN 3
Contents

7.12 Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8 Code list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
9 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10 Servicing explosion-protected devices . . . . . . . . . . . . . . . . . 47
11 Dimensions in mm . . . . . . . . . . . . . . . . . . . . . . . . . . 48
11.1 Fixing levels according to VDI/VDE 3845 (September 2010) . . . . . . 49
Test certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4EB 8394 EN
Contents

EB 8394 EN 5
Firmware revisions
Firmware revisions
1.02 (previous) 1.03 (new)
Internal revisions

1 Safety instructions
For your own safety, follow these instructions concerning the mounting, start up and opera-
tion of the positioner:
4The positioner is to be mounted, started up or operated only by trained and experi-
enced personnel familiar with the product.
According to these Mounting and Operating Instructions, trained personnel refers to
individuals who are able to judge the work they are assigned to and recognize possi-
ble dangers due to their specialized training, their knowledge and experience as well
as their knowledge of the relevant standards.
4Explosion-protected versions of this positioner may only be operated by personnel
who have undergone special training or instructions or who are authorized to work
on explosion-protected devices in hazardous areas.
4Any 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.
4If inadmissible motions or forces are produced in the actuator as a result of the supply
pressure, the supply pressure must be restricted by means of a suitable supply pres-
sure reducing station.
4Proper shipping and appropriate storage are assumed.
To avoid damage to any equipment, the following also applies:
4Do not operate the positioner with the back of the positioner/vent opening facing up-
wards.
The vent opening must not be sealed when the positioner is installed on site.
4Do not ground electric welding equipment near to the positioner.
Note: The device with a CE marking fulfills the requirements of the Directives 94/9/EC
(ATEX) and 89/336/EEC (EMC).
The Declaration of Conformity is available on request.
6EB 8394 EN
Safety instructions
Vent opening

2 Article code
EB 8394 EN 7
Article code
Positioner Type 3725- xxx00000009999
With LCD and autotune, 4 to 20 mA reference variable
Explosion protection*
Without 000
II 2 G Ex ia IIC T4 acc. to ATEX 1100
* Other approvals in preparation

3 Design and principle of
operation
The electropneumatic positioner is mounted
on pneumatic control valves. It is used to as-
sign the valve stem position (controlled vari-
able x) to the control signal (reference vari-
able w). The electric control signal received
from a control system is compared to the
travel or rotational angle of the control valve
and a signal pressure (output variable y) is
produced for the pneumatic actuator.
The positioner consists of an anisotropic
magnetoresistive (AMR) sensor (2), an ana-
log i/p converter (7) with a downstream
booster and the electronics unit with
microcontroller (4).
The travel or opening angle is measured by
the pick-up lever connected to a magnet and
a non-contact AMR sensor (2) installed in
the housing and the electronics.
The motion of the pick-up lever causes the
direction of the magnetic field to change.
This change is sensed by the AMR sensor.
The microprocessor determine the momen-
tary valve position from this information.
The position of the valve is transmitted to the
microcontroller (4) over the A/D converter
(3). The PD control algorithm in the micro-
processor (4) compares this actual position
to the 4 to 20 mA control signal (reference
variable) after it has been converted by the
A/D converter (3).
In case of a system deviation, the operation
of the i/p converter (6) is changed so that
the actuator (1) is filled or vented by the
downstream air capacity booster (7).
The pneumatic air capacity booster (7) and
the pressure regulator (8) are supplied with
supply air.
The output signal pressure supplied by the
booster can be limited to 2.4 bar by soft-
ware.
The volume restriction Q (10) is used to opti-
mize the positioner by adapting it to the ac-
tuator size.
Tight-closing function
The pneumatic actuator is completely filled
with air or vented as soon as the reference
variable falls below 1 % or exceeds 99 %
(see end positions set over parameter codes
P10 and P11).
Air to open (ATO): P10 ®ON; P11 ®OFF
Air to close (ATC): P10 ®OFF; P11 ®ON
8EB 8394 EN
Design and principle of operation

EB 8394 EN 9
Design and principle of operation
%
S
mm
%
mm
Q
34
11
6
7
8
10
1
w
9
x
y
2
5
Fig. 2 · Functional diagram
1 Control valve
2 AMR sensor
3 A/D converter
4 Microcontroller
5 D/A converter
6 i/p converter
7 Air capacity booster
8 Pressure regulator
9 Fixed restriction
10 Volume restriction
11 Display

3.1 Technical data
10 EB 8394 EN
Technical data
Type 3725 Positioner
Travel, adjustable Direct attachment to Type 3277 Actuator: 3.75 to 30 mm
Attachment acc. to IEC 60 534-6-1 (NAMUR): 3.75 to 50 mm
Attachment to Type 3372 Actuator: 15/30 mm
Attachment to rotary actuators: 24 to 100°
Reference
variable w
Signal range 4 to 20 mA · Two-wire device with reverse polarity protection
Split range
operation 4 to 11.9 mA and 12.1 to 20 mA
Static destruction
limit ±33 V
Minimum current 3.8 mA
Load impedance £6 V (corresponds to 300 Wat 20 mA)
Supply air
Supply pressure 1.4 to 7 bar (20 to 105 psi)
Air quality
acc. to
ISO 8573-1 (2001)
Max. particle size and density: Class 4 · Oil content: Class 3
Pressure dew point: Class 3 or at least 10 K below the lowest ambient temperature
to be expected
Signal pressure (output) 0 bar up to the capacity of the supply pressure · Can be limited to approx. 2.4
bar by software
Characteristics 3 characteristics for globe valves · 9 characteristics for rotary valves
Hysteresis £0.3 %
Sensitivity £0.1 %
Transit time < 0.5 s not permissible for initialization, adaptation using volume restriction
Direction of action w/x reversible
Air consumption £100 ln/h with a supply pressure up to 6 bar and a signal pressure of 0.6 bar
Air output
capacity
Actuator pressurized At Dp = 6 bar: 8.5 mn³/h ·At Dp = 1.4 bar: 3.0 mn³/h ·KVmax (20 °C) = 0.09
Actuator vented At Dp = 6 bar: 14.0 mn³/h · At Dp = 1.4 bar: 4.5 mn³/h · KVmax (20 °C) = 0.15
Permissible ambient temperature –25 to +80 °C
Limits in test certificates additionally apply for explosion-protected devices.
Influences
Temperature £0.15 %/10 K
Supply air None
Vibrations £0.25 % up to 2000 Hz and 4 g according to IEC 770
Electromagnetic compatibility Complying with the requirements of EN 61000-6-2, EN 61000-6-3, EN 61326-1
and NAMUR Recommendation NE 21
Electrical connections One M20x1.5 cable gland for 6 to 12 mm clamping range
Cage clamp terminals for 0.2 to 1.5 mm² wire cross-sections
Explosion protection II 2 G Ex ia IIC T4
Degree of protection IP 66