T 8493S EN
TROVIS SAFE 3793 Smart Positioner (HART®) for on/off valves in safetyinstrumented systems

Application
Single-acting or double-acting positioner for attachment to pneumatic on/off valves in safety-instrumented systems.
Self-calibrating, automatic adaptation to valve and actuator.
Set point
Valve travel
Opening angle

4 to 20 mA
3.6 to 300 mm
24 to 170°

The discrete analysis of the set point w is performed in automatic mode. The positioner moves the valve to the operating
point or fail-safe position depending on the adjustable limits.
An automated partial stroke test is started when the set point
is between the predefined upper and lower test limits.
TROVIS 3793 Positioner used for throttling service u T 8493.
Special features• High air capacity• Modular design: easy retrofitting or exchange of pneumatic or option modules• Integrated EXPERTplus diagnostics with partial stroke testing for valves in safety-instrumented systems u T 8389-2S• Simple attachment to all common linear and rotary actuators:
–
–
–
–
–

running without having to change the valve position.
• All parameters saved in non-volatile EEPROM• Two-wire system with a small electrical load of 495 Ω• Adjustable tight-closing function• Continuous zero monitoring• Integrated temperature sensor and operating hours
counter• Self-diagnostics, messages as condensed state conforming
to NAMUR Recommendation NE 107• Pressure sensors to monitor the supply air and signal pressure• Air capacity adjustable by software

SAMSON direct attachment
NAMUR rib
Attachment to rod-type yokes according toIEC 60534-6-1
Attachment according to VDI/VDE 3847
Rotary actuator attachment according to VDI/
VDE 3845• Non-contact position sensing• Plain-text display with NAMUR Recommendation NE 107
states and messages on the device• Integrated diagnostic functions• Simple one-knob, menu-driven operation• LCD easy to read in any mounting position thanks to selectable reading direction• Configurable with a computer over the SSP interface using
the TROVIS-VIEW software• Variable, automatic start-up with four different initialization modes• Sub (substitution) initialization mode allows the positioner
to be started up in case of emergency whilst the plant is

Fig. 1: TROVIS SAFE 3793 Electropneumatic Positioner

SAMSON AKTIENGESELLSCHAFT · Weismüllerstraße 3 · 60314 Frankfurt am Main, Germany
Phone: +49 69 4009-0 · Fax: +49 69 4009-1507 · samson@samsongroup.com · www.samsongroup.com

Edition July 2021

Design and principle of operation
The TROVIS SAFE 3793 Electropneumatic Positioner is mounted on pneumatic control valves and used to assign the valve
position (controlled variable x) to the control signal (set pointw). The discrete analysis of the set point w is performed in automatic mode. The positioner moves the valve to the operating
point or fail-safe position depending on the defined limits. An
automated step response test is started when the set point is
between the predefined upper and lower test limits.
The positioner mainly consists of a non-contact travel sensor
system (2), pneumatics and the electronics with the microcontroller (4). The output of the standard version is either single or
double acting; which means both the Output 138 and Output 238 can provide the output variable and route the signal
pressure to the actuator.
The positioner can be configured to meet requirements of an
application by adding a maximum of two pneumatic modules(A, B) and electronic option modules (C, D). The pneumatic
modules mainly consist of a microcontroller, which operates
an i/p converter with downstream spool valve. Depending on
the actuator used, an output of the positioner can be sealed toachieve a single-acting function. The option modules additionally provide individual functions, e.g. recognition of the end
positions.

Serial 6
Interface

9

7 FSK

3

The pneumatic module is supplied with air. The flow rate of
the module's output can be restricted by software.
The positioner is operated by a rotary pushbutton (9) for
menu navigation on the plain-text display (8).
The extended EXPERTplus diagnostics are integrated into thepositioner. They provide information on the control valve andpositioner and generate diagnostic and status messages,
which allow faults to be pinpointed quickly.

8

M

#

#
w

The valve position is transmitted either as an angle of rotation
or a travel to the pick-up lever, from there to the travel sensor(2) and forwarded to the microcontroller (4). The PID algorithm in the microcontroller compares the valve position measured by the travel sensor (2) to the 4 to 20 mA DC control
signal issued by the control system after it has been converted
by the A/D converter (3). In case of a set point deviation, thepneumatic module (A, B) causes the actuator (1) to be either
vented or filled with air. As a result, the closure member of thevalve (e.g. plug) is moved to the position determined by theset point.

M.1

4

E

µC

#

C
I

M.3

&

A

D

B

2

p/#
p/#

Exh

Exhaust 79

Output 238

Output 138

y

M.4
M.5
M.6

p/#

Supply 9

M.2

5

1
x

M
M.1
M.2
M.3
M.4
M.5
M.6

1
2
3
4
5
6
7
8
9

Control valve
Travel sensor
A/D converter
Microcontroller
Pressure sensors
Communication interface
HART® connection
Display
Rotary pushbutton

A
B
C
D

Slot for pneumatic module A
Slot for pneumatic module B
Slot for option module C
Slot for option module D

Available option modules
Software limit switches with binary output (NAMUR)
Software limit switches with binary output (PLC)
Inductive limit switches with binary output (NAMUR)
Mechanical limit switches
Position transmitter with binary input and output
Forced venting with binary input and output

Fig. 2: Block diagram of TROVIS SAFE 3793 Positioner

2

T 8493S EN

Technical data · TROVIS SAFE 3793 Positioner
TravelAdjustable travel for

Direct attachment to Type 3277:
Attachment according to IEC 60534-6 (NAMUR):
Attachment according to VDI/VDE 3847
Attachment to rotary actuators:

3.6 to 30 mm
5 to 300 mm
5 to 300 mm
24 to 100° (170° 1))

Set point w
Signal range

4 to 20 mA, two-wire device, reverse polarity protection,
split-range operation (can be configured as required, minimum span 4 mA)

Static destruction limit

40 V, internal current limit approx. 40 mA

Minimum current

3.75 mA for display/operation (HART® communication and configuration)
3.90 mA for pneumatic function

Load impedance≤ 9.9 V (corresponds to 495 Ω at 20 mA)

Supply air
Supply air

2.5 to 10 bar/30 to 150 psi

Air quality acc. to ISO 8573-1

Max. particle size and density:
Oil content:
Pressure dew point:

Signal pressure (output)

0 bar up to supply pressure

Hysteresis≤0.3 %

Sensitivity≤0.1 %, adjustable by software

Start-up time

After interrupted operation < 300 ms: 100 ms
After interrupted operation > 300 ms: ≤2 s

Transit time

Up to 10000 s separately adjustable for exhaust and supply by software

Class 4
Class 3
Class 3 or at least 10 K below the lowest ambient
temperature to be expected

Direction of action

Reversible

Air consumption≤300 ln/h with 6 bar supply pressure, depending on module2)

Air output capacity (when ∆p = 6 bar)
Actuator (supply)

32 mn³/h with one pneumatic module (KV max (20 °C) = 0.34)
60 mn³/h with two pneumatic modules of the same sort (KV max (20 °C) = 0.64)

Actuator (exhaust)

37 mn³/h with one pneumatic module (KV max (20 °C) = 0.40)
70 mn³/h with two pneumatic modules of the same sort (KV max (20 °C) = 0.75)

Environmental conditions and permissible temperatures
Permissible environmental conditions according to EN 60721-3
Storage

1K6 (relative humidity ≤95 %)Transport

2K4
4K4

Operation–20 to +85 °C: All versions–40 to +85 °C: With metal cable glands–55 to +85 °C: Low-temperature versions with metal cable glands
Observe the limits in the test certificate for explosion-protected versions.

Resistance to vibration

1)
2)

Vibrations (sinusoidal)

According to DIN EN 60068-2-6:
0.15 mm, 10 to 60 Hz; 20 m/s², 60 to 500 Hz per axis
0.75 mm, 10 to 60 Hz; 100 m/s², 60 to 500 Hz per axis

Bumps (half sine)

According to DIN EN 60068-2-29: 150 m/s², 6 ms; 4000 bumps per axis

Noise

According to DIN EN 60068-2-64: 10 to 200 Hz: 1 (m/s²)²/Hz; 200 to 500 Hz: 0.3 (m/s²)²/Hz;
4 h/axis

Recommended continuous operation≤20 m/s²

On request
Based on temperature range –40 to +85 °C

T 8493S EN

3Influences
Temperature≤0.15 %/10 K

Supply air

None

Requirements
EMC

Complying with EN 61000-6-2, EN 61000-6-3, EN 61326-1 and NAMUR Recommendation NE 21

Degree of protection

IP 66

Conformity
Electrical connections
Cable glands

Max. four, M20x1.5 or ½ NPT

Terminals

Screw terminals for 0.2 to 2.5 mm² wire cross-section(max. 1.5 mm² with the option modules)

Explosion protection
See table for explosion protection certificates
Materials
Housing and coverDie-cast aluminum EN AC-AlSi12(Fe) (EN AC-44300) acc. to DIN 1706, chromate and powder
coating

Window

Makrolon® 2807

Cable glands

Polyamide, nickel-plated brass, stainless steel 1.4305

Other external parts

Stainless steel 1.4571 and 1.4404 (316 L)

Weight
1.4 to 1.6 kg (depending on version)

Summary of explosion protection certificates for TROVIS SAFE 3793 Positioner
TROVIS SAFE 3793

Certification

-110

Date

2016-12-01

Number BVS 16 ATEX E117

-510

ATEX
-810

Date

2016-12-01

Number BVS 16 ATEX E117
Date

2016-12-01

Number BVS 16 ATEX E123

-850

Date

2016-12-01

II 2 G Ex ia IIC T4/T6 Gb
II 2 D Ex ia IIIC T 85 °C Db
II 2 D Ex tb IIIC T 85 °C Db
II 3 G Ex nA IIC T4/T6 Gc
II 2 D Ex tb IIIC T 85 °C Db
II 3 G Ex nA IIC T4/T6 Gc

Number TC RU C-DE.PB.B.00127
2018-06-28
Date

1Ex ia IIC T4/T6 Gb X
Ex ia IIIC T85°C Db X

Number TC RU C-DE.PB98.B.00127
2018-06-28
Date

2Ex nA IIC T4/T6 Gc X
Ex tb IIIC T85°C Db X

-111

Number IECEx BVS 16.0084
2016-12-07
Date

Ex ia IIC T4/T6 Gb
Ex ia IIIC T 85 °C Db-511

Number IECEx BVS 16.0084
2016-12-07
Date

Ex tb IIIC T 85 °C Db

Number IECEx BVS 16.0084
2016-12-07
Date

Ex nA IIC T4/T6 Gc
Ex tb IIIC T 85 °C Db

Number IECEx BVS 16.0084
2016-12-07
Date

Ex nA IIC T4/T6 Gc

-113
-813

-811

EAC

IECEx

-851

Number FM16CA0218X
2018-01-06
Date

IS Class I, II, III, Division 1,
Groups A, B, C, D, E, F, G; Type 4X
NI Class I, II, III, Division 2,
Groups A, B, C, D, E, F, G; Type 4X
Class I, Zone 1, AEx ia IIC; Type 4X-112

Number GYJ17.1245X
2017-11-21
Date

Ex ia IIC T6...T4 Gb
Ex iaD 21 T85-512

Number GYJ17.1245X
2017-11-21
Date

Ex tD A21 IP66 T85°C

Number GYJ17.1245X
2017-11-21
Date

Ex nA IIC T6...T4 Gc
Ex tD A21 IP66 T85°C

Number GYJ17.1245X
2017-11-21
Date

Ex nA IIC T4...T6 Gc

-130

-812
-852

4

Type of protection
Number BVS 16 ATEX E117

FM

NEPSI

T 8493S EN

Technical data · Optional additional functions
Analog position transmitter
VersionTwo-wire system, galvanic isolation, reverse polarity protection, reversible direction of action

Auxiliary power

10 to 30 V DC

Output signal

4 to 20 mA

Operating range

3.8 to 20.5 mA

Error indication

2.4 or 21.6 mA

No-load current

1.4 mA

Static destruction limit

38 V DC · 30 V AC

Software limit switches
VersionSignal state

NAMUR

Galvanic isolation, reverse polarity protection,
binary input of a PLC acc. to EN 61131-2,
Pmax = 400 mW

Non-conducting≤1.0 mA

Non-conducting

Conductive≥2.2 mA

Conductive (R = 348 Ω)

Static destruction limit

32 V DC/24 V AC

Binary output

16 V DC/50 mA
NAMUR

VersionSignal state

PLC

Galvanic isolation, reverse polarity protection,
switching output acc. to EN 60947-5-6

Non-conducting
Conductive

Static destruction limit

PLC

Galvanic isolation, reverse polarity protection,
switching output acc. to EN 60947-5-6

Galvanic isolation, reverse polarity protection,
binary input of a PLC acc. to EN 61131-2,
Pmax = 400 mW≤1.0 mA

Non-conducting≥2.2 mA

Conductive (R = 348 Ω)

32 V DC/24 V AC

32 V DC/50 mA

Binary input
Version

Galvanic isolation, reverse polarity protection

Voltage input

0 to 24 V DC

Input resistance≥7 kΩON switching state

Ue >15 V

OFF switching state

Ue <11 V

Static destruction limit

38 V DC/30 V AC

Forced venting
Version

Galvanic isolation, reverse polarity protection

Voltage input

0 to 24 V DC

Input resistance
Signal state≥7 kΩ
ActiveUe <11 V

Not active

Ue >15 V

Static destruction limit

38 V DC/30 V AC

Inductive limit switches
VersionFor connection to switching amplifier according to EN 60947-5-6, SJ2-SN proximity switches, reverse
polarity protection

Measuring plate not detected≥3 mA

Measuring plate detected≤1 mA

Static destruction limit

20 V DC

Permissible ambient temperature–50 to +85 °C

Mechanical limit switches
Floating contact

Changeover contact/SPDT (single-pole/double-throw type)

Static destruction limit

38 V DC · 30 V AC · 0.2 A

Permissible ambient temperature–40 to +85 °C

Pressure sensors
Pressure sensors
Pressure range

0 to 14 bar

Permissible ambient temperature–40 to +85 °C

T 8493S EN

5

Mounting the positioner

Table 2: Available option modules

The positioner can be attached directly to the Type 3277 Actuator (175 to 750 cm²) over a connection block. In actuatorswith “actuator stem extends” fail-safe action, the signal pressure is routed over an internal hole in the actuator yoke to theactuator. In actuators with “actuator stem retracts” fail-safe action, the signal pressure is routed to the actuator over readymade external piping.
Using the appropriate bracket, the positioner can also be attached according to IEC 60534-6-1 (NAMUR recommendation). The positioner can be mounted on either side of the control valve.
A pair of universal brackets is used for the attachment toType 3278 Rotary Actuators or other rotary actuators according to VDI/VDE 3845. The rotary motion of the actuator istransferred to the positioner over a coupling wheel with travelindication.

Function
Inductive limit switches
Mechanical limit switches
Software limit switches (NAMUR)
Software limit switches (PLC)
Analog position transmitter
Forced venting
Binary input
Article code

Binary output

Z3799-xxx10•

Z3799-xxx11
Z3799-xxx15
Z3799-xxx30

•
•

•

•

•
•

Z3799-xxx40
Z3799-xxx80

•
•

•

•

•

•

A special version of the positioner allows it to be attached according to VDI/VDE 3847. This type of attachment allows the
positioner to be replaced quickly while the process is runningby blocking the air in the actuator. The positioner can be attached directly to the Type 3277 Actuator using an adapter
bracket or adapter block. Alternatively, it can be attached to
the NAMUR rib of a control valve using an additional
NAMUR connection block.
VersionThe TROVIS SAFE 3793 Electropneumatic Positioner can beused as a single or double-acting positioner, depending on
the combination of the available pneumatic modules.
The modular design also allows diverse optional additional
functions (option modules) to be added and adapt the positioner on site to the specific requirements.
–

Fig. 3: Pneumatic module

TROVIS SAFE 3793 · Electropneumatic positioner for on/
off valves, HART® communication, on-site operation, local
communication with SSP interface, EXPERTplus diagnostics, pressure sensors to monitor the supply air and signal
pressure

Optional modules
The modular design of the positioner allows it to be adaptedto specific requirements. The air capacity and direction of action can be varied by the installation of different pneumatic
modules (Fig. 3). Optional additional functions are available
by using option modules (Fig. 4 and Fig. 5).

Fig. 4: Option module

If the positioner is ordered with additional pneumatic modules
and/or option modules, they are ready installed and connected upon delivery.
Table 1: Available pneumatic modules

6

Article code

Function

P3799-0000

Dummy module (seals the slot connections andmust be used when only one pneumatic module isinstalled)

P3799-0001

Output 138 and Output 238 module (single anddouble acting)

P3799-0002

Output 138 module (single acting)

P3799-0003

Output 238 module (single acting)Fig. 5: Option module with hardware limit switches

T 8493S EN

Operation
The positioner is operated using one proven, user-friendly rotary pushbutton: the various menu levels, parameters and values are selected by turning the button. By pressing the button,
the required setting is activated. All parameters can bechecked and changed on site.
All values are displayed on the plain-text display. The reading
direction of the display can be rotated by 180°.
The initialization key activates initialization which is started

according to the ready adjusted parameters (autotune). Afterinitialization is completed, the positioner immediately starts
closed-loop operation.
To configure the positioner with SAMSON’s TROVIS-VIEW
software, the positioner is equipped with an additional digitalinterface to be connected to the USB interface of a computer
using an adapter.
Additionally, all parameters of the TROVIS SAFE 3793 Positioner can be accessed using HART® communication.

14

24

44

102

277

Dimensions in mm

40

58

28

87

10...17

16

212

Attachment according to IEC 60534-6 (NAMUR)

70

Pressure gauge bracket

15
46

58

34

T 8493S EN

7

13

62

24

278

211

Attachment according to VDI/
VDE 3847 onto Type 3277 Actuator

164

13

62

38

278

211

Attachment according to VDI/
VDE 3847 to a NAMUR rib

164

8

T 8493S EN

86

56

Attachment to rotary actuators according to VDI/VDE 3845
Fixing level 1, AA1 to AA4 size

80

30
86

130

Ø101

166

Lever
z
y
x

Lever

x

y

z

M

25 mm

50 mm

66 mm
116 mm

L

70 mm

100 mm

XL

100 mm

200 mm

216 mm

XXL

200 mm

300 mm

316 mmFixing levels according to VDI/VDE 3845 (September 2010)
Mmin
Fixing level 2 (bracket surface)

25

M6
C

Fixing level 1 (actuator surface)
Actuator

Dimensions in mm

Ød

B

ØD
A

1)

T 8493S EN

Size

A

B

C

Ød

Mmin

D1)

AA0

50

25

15

5.5 for M5

66

50

AA1

80

30

20

5.5 for M5

96

50

AA2

80

30

30

5.5 for M5

96

50

AA3

130

30

30

5.5 for M5

146

50

AA4

130

30

50

5.5 for M5

146

50

AA5

200

50

80

6.5 for M6

220

50

Flange type F05 acc. to DIN EN ISO 5211

9

Pressure gauge bracket, twopressure gauges

46

Pressure gauge bracket, threepressure gauges

100

72

46

Connecting plate

15

10

T 8493S EN

Electrical connection
–12

+11

Set point (mA signal)
Table 3: Slot position and terminal assignment of the option modules
Z3799-xxx10 [N] · Software limit switches with binary output (NAMUR)
Slot

Terminal assignment

C or D
Description

Terminal

Software limit switch (NAMUR 1)

N

Software limit switch (NAMUR 2)

N
N

Binary output (NAMUR)

+45
–46
+55
–56
+83
–84

Z3799-xxx11 [X] · Software limit switches with binary output (PLC)
Slot

Terminal assignment

C or D
Description

Terminal

Software limit switch (PLC 1)

X
X

Software limit switch (PLC 2)

X

Binary output (PLC)

+91
–92
+93
–94
+95
–96

Z3799-xxx14 [P] · Inductive limit switches with binary output (NAMUR)
Slot

Terminal assignment

D
Description

Terminal

Binary output (NAMUR)

P
P

Inductive limit switch 1

P

Inductive limit switch 2

+83
–84
+41
–42
+51
–52

Z3799-xxx30 [M] · Mechanical limit switches
Slot

Terminal assignment

D
Description
Mechanical limit
switch 1(changeover contact)
Mechanical limit
switch 2(changeover contact)

T 8493S EN

Switching
function

Terminal
47

NC
C

M

48

NO

49

NC

57

C
NO

M

58
59

11

Z3799-xxx40 [T] · Position transmitter with binary input (24 V) and binary output (NAMUR)
Slot

Terminal assignment

C or D
Description

Terminal

Position transmitter 4 to 20 mA

T

+31
–32
+87

T

Binary input 24 V

–88
+83

T

Binary output (NAMUR)–84

Z3799-xxx80 [V] · Forced venting with binary input (24 V) and binary output (NAMUR)
Slot

Terminal assignment

C or DNOTICE!
Observe rotaryswitch position forforced venting.

Description

Terminal

Forced venting

V
V

Binary input 24 V

V

Binary output (NAMUR)

+81
–82
+87
–88
+83
–84

Article code
Positioner

TROVIS SAFE 3793- x

x

x

5

x

x

0

1

x

x

x

x

x

x

0

0

0

x

0

x

0

x

0

0

9

9

x

x

With LCD, autotune, HART® communication
Explosion protection
Without

ATEX

EAC

IECEx

FM

NEPSI

0

0

0

II 2 G Ex ia IIC T4/T6 Gb
II 2 D Ex ia IIIC T 85 °C Db

1

1

0

II 2 D Ex tb IIIC T 85 °C Db

5

1

0

II 3 G Ex nA IIC T4/T6 Gc
II 2 D Ex tb IIIC T 85 °C Db

8

1

0

II 3 G Ex nA IIC T4/T6 Gc

8

5

0

1Ex ia IIC T4/T6 Gb X
Ex ia IIIC T85°C Db X

1

1

3

2Ex nA IIC T4/T6 Gc X
Ex tb IIIC T85°C Db X

8

1

3

Ex ia IIC T4/T6 Gb
Ex ia IIIC T 85 °C Db

1

1

1

Ex tb IIIC T 85 °C Db

5

1

1

Ex nA IIC T4/T6 Gc
Ex tb IIIC T 85 °C Db

8

1

1

Ex nA IIC T4/T6 Gc

8

5

1

IS Class I, II, III, Division 1,
Groups A, B, C, D, E, F, G; Type 4X
NI Class I, II, III, Division 2,
Groups A, B, C, D, E, F, G; Type 4X
Class I, Zone 1, AEx ia IIC; Type 4X

1

3

0

Ex ia IIC T6...T4 Gb
Ex iaD 21 T85

1

1

2

Ex tD A21 IP66 T85°C

5

1

2

Ex nA IIC T6...T4 Gc
Ex tD A21 IP66 T85°C

8

1

2

Ex nA IIC T4...T6 Gc

8

5

2

Pneumatics
Single/double acting, KV = 0.35
Single/double acting, KV = 0.70

02Single acting, 2x independent KV = 0.35

0

3

12

T 8493S EN

Positioner

TROVIS SAFE 3793- x

x

x

5

x

x

x

x

x

x

Without/dummy module00Software limit switches + binary output (NAMUR), [N]10Software limit switches + binary output (PLC), [X] 1)

1

1

Inductive limit switches + binary output (NAMUR), [P]; –50 to +85 °C

1

5

x

x

0

0

0

x

0

x

0

x

0

0

9

9

9

9

x

x

9

6

Option module 1 (slot C)
Without/dummy module00Software limit switches + binary output (NAMUR), [N]10Software limit switches + binary output (PLC), [X] 1)

1

1

Position transmitter + binary input/output (NAMUR), [T]40Forced venting + Binary input/output (NAMUR), [V]80

Option module 2 (slot D)

Mechanical limit switches, [M]; –40 to +85 °C

30Position transmitter + binary input/output (NAMUR), [T]40Pressure sensors
Without

0Standard (Supply 9, Output 138, Output 238); –40 to +85 °C

1Electrical connection
M20x1.5 (one cable gland, three blanking plugs)

1½-14 NPT (one cable gland, three blanking plugs)

4

Housing material
Aluminum (standard)0

Special applications
Without

0

Additional certification
Without

0

Permissible ambient temperatureStandard: –20 to +85 °C, plastic cable gland0–40 to +85 °C metal cable gland

1–55 to +85 °C, low-temperature version with metal cable gland2

Display text in different languages
Standard (English and German)

0

Special version
Without

0

Cover without window

1

Hardware version
1.00.00
Firmware version
1.00.05
1)

The option module for Software limit switches + Binary output (PLC), [X] is not available in the explosion-protection version.

T 8493S EN

13

T 8493S EN

2023-09-25 · English

Specifications subject to change without notice