ABB 261GS User manual

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ABB MEASUREMENT & ANALYTICS | OPERATING INSTRUCTION
Pressure transmitter
Models 261GS/GC/GG/GJ/GM/GN/GR
Models 261AS/AC/AG/AJ/AM/AN/AR
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ABB Limited
Measurement & Analytics
Howard Road, St. Neots
Cambridgeshire, PE19 8EU
UK
Tel: [phone]
Fax: [phone]
Email: [e-mail]
ABB Automation Products GmbH
Measurement & Analytics
Schillerstr. 72
32425 Minden
Germany
Tel: [phone]
Fax: [phone]
abb.com/pressure
ABB Inc.
Measurement & Analytics
125 E. County Line Road
Warminster, PA 18974
USA
Tel: [phone]
Fax: [phone]
ABB S.p.A.
Measurement & Analytics
Via Luigi Vaccani 4
22016 Tremezzina (CO)
Italy
Tel: [phone]
Email: abb.instrumentatio[email protected].com
Measurement made easy
IM/261Gx/261Ax-EN Rev. 08 11.2018
—
261Gx, 261Ax
Additional Information
Additional documentation on 261Gx, 261Ax is
available for download free of charge at
www.abb.com/pressure.
Alternatively simply scan this code:
—
We reserve the right to make technical changes or modify the contents of this document without prior
notice. With regard to purchase orders, the agreed particulars shall prevail.
ABB does not accept any responsibility whatsoever for potential errors or possible lack of information in
this document.
We reserve all rights in this document and in the subject matter and illustrations contained therein. Any
reproduction, disclosure to third parties or utilization of its contents – in whole or in parts – is forbidden
without prior written consent of ABB.
Copyright© 2018 ABB
All rights reserved 3KXP200001R4201

2 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
Models 261GS/GC/GG/GJ/GM/GN/GR
Models 261AS/AC/AG/AJ/AM/AN/AR
Pressure transmitter
Operating Instruction
IM/261Gx/Ax-EN
Rev. 08
Issue date: 11.2018
Original instruction
Manufacturer
ABB Automation Products GmbH
Measurement & Analytics
Schillerstr. 72
32425 Minden
Germany
Tel: [phone]
Fax: [phone]
Customer service center
Tel.: [phone]
Fax: [phone]-29031
[email protected]

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 3
Change from one to two columns
Contents
1Safety............................................................................... 5
1.1General information and notes for the reader........ 5
1.2Intended use........................................................ 5
1.3Improper use ....................................................... 5
1.4Target groups and qualifications .......................... 5
1.5Warranty provisions ............................................. 5
1.6Plates and symbols.............................................. 6
1.6.1Safety / warning symbols, note symbols .............. 6
1.7Name plate.......................................................... 6
1.8Compliance with Pressure Equipment Directive
(2014/68/EU) ....................................................... 7
1.9Transport safety instructions ................................ 7
1.10Storage conditions............................................... 7
1.11Safety instructions for electrical installation........... 7
1.12Safety instructions for operation........................... 7
1.13Returning devices ................................................ 7
1.14Integrated management system........................... 8
1.15Disposal .............................................................. 8
1.15.1Notice on WEEE Directive 2012/19/EU (Waste
Electrical and Electronic Equipment)..................... 8
1.15.2ROHS Directive 2011/65/EU................................ 8
2Use in potentially explosive atmospheres ..................... 9
2.1Explosion protection ............................................ 9
2.2Type-examination certificate/Declaration of
conformity ........................................................... 9
2.3Type of protection "intrinsic safety Ex i"................ 9
2.4Use in areas with combustible dust...................... 9
2.5Category 3 (EPL Gc) with type of protection "nA". 9
2.6Use of handheld terminal / PC ............................. 9
3Function and system design......................................... 10
3.1Operation and system setup .............................. 10
4Mounting ....................................................................... 12
4.1Pressure transmitter........................................... 12
4.2Sealing and screw connections.......................... 13
4.3Moisture ............................................................ 13
4.4Measuring pipe.................................................. 14
5Electrical connections................................................... 15
5.1Cable connection............................................... 15
5.2Electrical connection in the cable connection area
.......................................................................... 16
5.3Electrical connection with plug........................... 17
5.3.1Assembly and connection of Han 8D (8U) socket
connector .......................................................... 18
5.4Protective conductor/Grounding (optional) ......... 18
5.5Communication setup........................................ 18
5.6Connecting cable............................................... 19
6Commissioning.............................................................. 20
6.1General remarks ................................................ 20
6.2Output signal ..................................................... 20
6.3Write protection ................................................. 20
6.4Adjusting lower range value / oblique sensor...... 21
6.5Installing/Removing the LCD indicator................ 22
6.6Pressure sensor ventilation ................................ 23
7Configuration, parameterization ................................... 24
7.1.1Standard configuration....................................... 24
7.2Configuration types............................................ 24
7.3Configuration using pushbutton on pressure
transmitter ......................................................... 24
7.3.1General remarks ................................................ 24
7.3.2Configuration ..................................................... 24
7.4Configuration with the LCD indicator.................. 25
7.4.1Menu navigation ................................................ 25
7.4.2Process display.................................................. 26
7.4.3Switching to the configuration level
(parameterization) .............................................. 26
7.4.4Menu structure .................................................. 27
7.4.5Parameter descriptions ...................................... 28
7.5Configuration with the graphical user interface
(DTM)................................................................. 31
7.5.1System requirements ......................................... 31
7.6Parameter descriptions ...................................... 31
7.7Configuration with the PC / laptop or handheld
terminal.............................................................. 33
7.8Configuration with the graphical user interface
(DTM)................................................................. 34
7.8.1System requirements ......................................... 34
7.9Parameter descriptions ...................................... 34
8Ex relevant specifications ............................................. 36
8.1Hazardous atmospheres.................................... 36
8.1.1ATEX transmitter with ‘intrinsic safety Ex ia/ib’ type
of protection in accordance with Directive
2014/34/EU....................................................... 36
8.1.2IECEx transmitter with the following types of
protection: ‘Intrinsic Safety ia’, ‘non sparking nA’
and ‘dust ignition protection by enclosure tb’ ..... 36
8.1.3Factory Mutual (FM) ........................................... 37
8.1.4Canadian Standards Association (CSA).............. 37
9Specification.................................................................. 38
9.1Functional specifications .................................... 38
9.1.1Measuring range limits and span limits ............... 38
9.1.2Span limits......................................................... 38
9.1.3Zero suppression and elevation.......................... 38
9.1.4Damping............................................................ 38
9.1.5Warm-up time.................................................... 38
9.1.6Insulation resistance........................................... 38
9.2Operating limits.................................................. 39
9.2.1Pressure limits ................................................... 39
9.2.2Temperature limits °C (°F) .................................. 39
9.2.3Limits for environmental effects .......................... 39
9.3Measuring accuracy........................................... 40
9.3.1Reference conditions according to IEC 60770.... 40
9.3.2Dynamic response (according to IEC 61298-1) ..40
9.3.3Measuring error for setting cut-off point.............. 40
9.3.4Ambient temperature ......................................... 40
9.3.5Temperature coefficient (Tk)............................... 40
9.3.6Power supply..................................................... 40
9.3.7Load.................................................................. 40
9.3.8Electromagnetic fields........................................ 40
9.3.9Mounting position .............................................. 40
9.3.10Long-term stability ............................................. 40
9.3.11Vibration effect................................................... 40

4 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
9.3.12Total performance ............................................. 41
9.4Technical specification....................................... 41
9.4.1Materials............................................................ 41
9.4.2Calibration ......................................................... 41
9.4.3Optional extras .................................................. 41
9.4.4Process connections ......................................... 41
9.4.5Electrical connections ........................................ 42
9.4.6Weight............................................................... 42
9.4.7Packaging ......................................................... 42
9.5Mounting dimensions......................................... 43
9.5.1Standard version ............................................... 43
9.5.2Version with the options “LCD indicator” and
“Harting Han plug”............................................. 44
9.5.3Transmitter with flush diaphragm ....................... 45
9.5.4Version with ball valve connection...................... 46
9.5.5Mounting with angle bracket (optional) ............... 47
10Maintenance / Repair.................................................... 48
10.1Removal ............................................................ 48
11Appendix ....................................................................... 49
11.1Approvals and certifications ............................... 49

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 5
1Safety
1.1 General information and notes for the reader
These instructions are an important part of the product and
must be retained for future reference.
Installation, commissioning, and maintenance of the product
may only be performed by trained specialist personnel who
have been authorized by the plant operator accordingly. The
specialist personnel must have read and understood the
manual and must comply with its instructions.
For additional information or if specific problems occur that are
not discussed in these instructions, contact the manufacturer.
The content of these instructions is neither part of nor an
amendment to any previous or existing agreement, promise or
legal relationship.
Modifications and repairs to the product may only be
performed if expressly permitted by these instructions.
Information and symbols on the product must be observed.
These may not be removed and must be fully legible at all
times.
The operating company must strictly observe the applicable
national regulations relating to the installation, function testing,
repair and maintenance of electrical products.
1.2 Intended use
261A pressure transmitters measure absolute pressure and
261G pressure transmitters gauge pressure or the level of
gases, vapors and liquids.
For information on measuring ranges and permissible
overload, refer to the section "Specifications".
Using these products as intended includes compliance with
the following points:
— Read and follow the instructions in this manual
— The technical limit values must be complied with (refer to
the section “Technical data").
1.3 Improper use
The following are considered to be instances of improper use
of the device:
— For operating as a flexible adapter in piping, e.g. for
compensating pipe offsets, pipe vibrations, pipe
expansions, etc.
— For use as a climbing aid, e.g. for mounting purposes
— For use as a support for external loads, e.g. as a support
for piping, etc.
— Material application, e.g. by painting over the housing,
name plate or welding/soldering on parts.
— Material removal, e.g. by spot drilling the housing.
1.4 Target groups and qualifications
Installation, commissioning and maintenance of the product
may only be performed by trained specialist personnel who
have been authorized by the plant operator to do so. The
specialist personnel must have read and understood the
manual and comply with its instructions.
The operators must strictly observe the applicable national
regulations with regards to installation, function tests, repairs,
and maintenance of electrical products.
1.5 Warranty provisions
Using the device in a manner that does not fall within the
scope of its intended use, disregarding this manual, using
underqualified personnel, or making unauthorized alterations
releases the manufacturer from liability for any resulting
damage. This renders the manufacturer's warranty null and
void.

6 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
1.6 Plates and symbols
1.6.1 Safety / warning symbols, note symbols
The warnings in these instructions are structured as follows:
DANGER
The signal word "DANGER" indicates an imminent danger.
Failure to observe this information will result in death or
severe injury.
WARNING
The signal word "WARNING" indicates an imminent danger.
Failure to observe this information may result in death or
severe injury.
CAUTION
The signal word "CAUTION" indicates an imminent danger.
Failure to observe this information may result in minor or
moderate injury.
NOTICE
The signal word "NOTICE" indicates useful or important
information about the product.
The signal word "NOTICE" is not a signal word indicating a
danger to personnel. The signal word "NOTICE" can also
refer to material damage.
1.7 Name plate
Fig. 1: Name plate for pressure transmitter model 261xx
1 Device type / Order code |
2 Options – additional information on the order code |
3 Device serial number (factory no.) | 4 Year of manufacture |
5 Identification code with reference to the Pressure Equipment
Directive (SEP or 1 G) | 6 Power supply | 7 Output signal |
8 Materials that come into contact with the medium |
9 Measuring range lower limit to measuring range upper limit (LRL to
URL) | 10 Measuring range, set to … | 11 HART output (process
variable) | 12 Measuring point tag (max. 32 characters) |
13 "SIL2" identification code (optional) | 14 Permissible pressure |
15 Degree of protection | 16 Software version |
17 Filling fluid, if present | 18 Minimum measuring span
Fig. 2: Additional name plate for devices intended for use in
explosion risk areas or for devices with direct mount or
remote seals (optional)
1 Serial number (factory no.) | 2 Type of protection |
3 Type of protection (continued) |
4 Number of the EC-type-examination certificate |
5 Order code for direct mount seal |
6 Type of seal, nominal diameter, max. pressure, temperature limits,
sealing surface, material, filling fluid |
7 Identification number of the notified body according to ATEX
(optional) | 8 Symbol: "Notice". Observe the specifications in the
operating instructions and type-examination certificate.
IMPORTANT (NOTICE)
For information on the individual letters/numbers that
make up the order code, please refer to the order
confirmation or associated data sheet.
For information about labeling in accordance with the
Pressure Equipment Directive, please observe the
information in "Compliance with Pressure Equipment
Directive".

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 7
1.8 Compliance with Pressure Equipment Directive
(2014/68/EU)
Devices with PS > 200 bar (20 MPa)
Devices with a permissible pressure of PS > 200 bar (20 MPa)
have been tested for conformity by the Technical Supervisory
Association TÜV NORD (0045) in accordance with module H
and can be used for fluids of group 1 (PED: 1G).
The name plate bears the following identification codes:
Fig. 3: Identification codes according to Pressure Equipment
Directive (example)
1 PED: 1G | 2 Identification number of the notified body according
to the Pressure Equipment Directive | 3 "SIL 2" identification code
(optional)
Devices with PS ≤ 200 bar (20 MPa)
Devices with a permissible pressure PS ≤ 200 bar (20 MPa)
conform to sec. 3 para. (3) and have not been tested for
conformity. The devices have been constructed and
manufactured according to sound engineering practice (SEP).
The CE marking on the device does not refer to the Pressure
Equipment Directive.
The name plate then contains the following identification
codes: PED: SEP.
1.9 Transport safety instructions
Observe the following instructions:
— Do not expose the device to humidity during transport.
Pack the device accordingly.
— Pack the device so that it is protected against vibrations
during transport, e.g., by using air-cushioned packaging.
Prior to installation, check the devices for possible damage
that may have occurred as a result of improper transport.
Details of any damage that has occurred in transit must be
recorded on the transport documents. All claims for damages
must be submitted to the shipper without delay and before
installation.
1.10 Storage conditions
— The device must be stored in dry and dust-free conditions.
Always keep the device in its original package during
storage / transport.
— Observe the permissible ambient conditions for transport
and storage according to the chapter “Technical Data”.
— In principle, the devices may be stored for an unlimited
period. However, the warranty conditions stipulated in the
order confirmation of the supplier apply.
1.11 Safety instructions for electrical installation
The electrical connection may only be established by
authorized specialist personnel and in accordance with the
connection diagrams.
The electrical connection information in this manual must be
observed; otherwise, the IP rating may be adversely affected.
Ground the measurement system according to requirements.
1.12 Safety instructions for operation
Before switching on the device, make sure that your
installation complies with the environmental conditions listed in
the chapter “Technical Data” or on the data sheet.
If there is a chance that safe operation is no longer possible,
take the device out of operation and secure it against
unintended startup.
1.13 Returning devices
Use the original packaging or a secure transport container of
an appropriate type if you need to return the device for repair
or recalibration purposes. Fill out the return form (see the
Appendix) and include this with the device.
According to the EU Directive governing hazardous materials,
the owner of hazardous waste is responsible for its disposal or
must observe the following regulations for shipping purposes:
All devices delivered to ABB must be free from any hazardous
materials (acids, alkalis, solvents, etc.).
Please contact Customer Center Service acc. to page 2 for
nearest service location.

8 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
1.14 Integrated management system
ABB Automation Products GmbH operates an integrated
management system, consisting of:
— ISO 9001 Quality management system,
— ISO 14001 Environmental management system,
— BS OHSAS 18001 Occupational health and safety
management system and
— Data and information protection management system.
Environmental awareness is an important part of our company
policy.
Our products and solutions are intended to have minimum
impact on the environment and on people during
manufacturing, storage, transport, use, and disposal.
This includes the environmentally-friendly use of natural
resources. We conduct an open dialog with the public through
our publications.
1.15 Disposal
This product is manufactured from materials that can be
recycled by specialist recycling companies.
1.15.1 Notice on WEEE Directive 2012/19/EU (Waste
Electrical and Electronic Equipment)
This product and its packaging are manufactured from
materials that can be recycled by specialist recycling
companies.
Bear the following points in mind when disposing of them:
— As of 8/15/2018, this product falls under the open scope
of application of the WEEE Directive 2012/19/EU and
relevant national laws (for example, ElektroG - Electrical
Equipment Act - in Germany).
— The product must be surrendered to a specialist recycling
company. Do not use municipal waste collection points.
According to WEEE Directive 2012/19/EU, these may be
used for products used in private applications only.
— If it is not possible to dispose of old equipment properly,
ABB Service can take receipt of and dispose of returns for
a fee.
NOTICE
Products which are marked with the adjacent
symbol may not be disposed of as unsorted
municipal waste (household waste). They should
be taken to a separate collection facility for
electric and electronic devices.
1.15.2 ROHS Directive 2011/65/EU
With the Electrical and Electronic Equipment Act (ElektroG) in
Germany, the European Directives 2012/19/EU (WEEE) and
2011/65/EU (RoHS) have been implemented into national law.
ElektroG defines the products that are subject to regulated
collection and disposal or reuse in the event of disposal or at
the end of their service life. ElektroG also prohibits the
marketing of electrical and electronic equipment that contains
certain amounts of lead, cadmium, mercury, hexavalent
chromium, polybrominated biphenyls (PBB), and
polybrominated diphenyl ethers (PBDE) (also known as
hazardous substances with restricted uses).

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 9
2Use in potentially explosive
atmospheres
2.1 Explosion protection
Explosion-protection should be conducted in accordance with
Directive 2014/34/EU (ATEX).
When installing explosion-proof transmitters (electrical
connection, grounding / potential equalization, etc.), observe
national regulations, DIN / VDE regulations and explosion-
protection directives.
The certified explosion-proof designation for the transmitter is
provided on the name plate.
2.2 Type-examination certificate/Declaration of
conformity
For transmitters with explosion-proof designs, the EU
declaration of conformity and this operating instruction should
be complied with. The EC type examination certificates to be
applied are available for download online on the ABB website.
2.3 Type of protection "intrinsic safety Ex i"
Only intrinsically safe devices may be installed in the
transmitter signal circuit. The signal circuit can be interrupted
while the transmitter is in operation (e.g., clamping/unclamping
signal lines).
The housing may be opened during operation.
Transmitters with and without remote seals and featuring type
of protection "intrinsic safety Ex i" may be directly integrated
into the partition separating Zone 0 and Zone 1 (sensor
diaphragm in Zone 0, transmitter in Zone1), provided that the
power is supplied via an intrinsically safe circuit with type of
protection "Ex ia".
2.4 Use in areas with combustible dust
Installation should be performed in accordance with the
EN 60079-14 installation regulations.
The transmitter should only be connected using cable glands
certified in accordance with Directive 2014/34/EU (ATEX). The
cable gland must conform to IP rating IP 67.
The smoldering temperature of the dust must be at least 75 K
above the maximum surface temperature of the transmitter.
The maximum surface temperature is 95 °C (203 °F) and is
obtained by adding together the maximum ambient
temperature (85 °C (185 °F)) and the maximum self-heating
(10 K).
WARNING! Risk of explosion!
When using remote seals with an anti-stick
coating, be aware of the risk of electrostatic
discharge (with consideration given to the filling
material and transport speed).
2.5 Category 3 (EPL Gc) with type of protection "nA"
The transmitter must be connected using a certified cable
gland (not included in scope of delivery). The cable gland must
satisfy the requirements of the ‘Increased safety Ex e’ type of
protection in accordance with Directive 2014/34/EU (ATEX).
Additionally, the conditions stipulated in the type-examination
certificate for the cable gland must be observed.
WARNING! Risk of explosion!
Opening the housing during operation (with the
supply voltage switched on) is not permitted.
Opening the cover presents a risk of spark
formation and, therefore, explosion.
Only open the housing when the supply voltage
is switched off.
2.6 Use of handheld terminal / PC
If a handheld terminal or a PC is being used for
communication / configuration / parameterization in a
potentially explosive atmosphere with type of protection
"intrinsic safety", the devices used must be certified
accordingly.
This applies even if the device is only connected for a short
period of time. This proof of "intrinsic safety" must be supplied
in addition to the transmitter.
WARNING! Risk of explosion!
The handheld terminal battery must not be
replaced in a potentially explosive atmosphere.
Replacing the battery presents a risk of spark
formation and, therefore, explosion.
The battery may only be replaced outside of the
potentially explosive atmosphere.

10 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
3Function and system design
Digital pressure transmitters are communication-ready field
devices with microprocessor-controlled electronics.
For bidirectional communication, an FSK signal is
superimposed on the 4 to 20 mA output signal in accordance
with the HART protocol.
The graphic user interface (DTM) can be used to configure,
poll, and test the pressure transmitter on a PC. Handheld
terminals also support communication.
For ‘local’ operation, a button is available on the device
electronics to set initial value and final value. In combination
with an optionally installed LCD indicator, a complete external
configuration and parameter setting of the transmitter can be
performed via the four local pushbutton controls.
The sturdy electronics housing is made of stainless steel and
is resistant to aggressive atmospheres. The process
connection is also made of stainless steel or Hastelloy C.
The name plate contains information about the specific
pressure transmitter design (see ‘Safety / Name plates’
chapter).
IMPORTANT (NOTICE)
For explosion-proof designs, the Ex design, or in
case of attached diaphragm seals, the
corresponding diaphragm seal type, is specified
on a separate plate.
In addition, a tag indicating the measuring points may be
attached (as an option).
3.1 Operation and system setup
The transmitter has a compact design and comprises the
pressure measuring cell and electronic unit with pushbutton
control. Depending on the measuring range and measured
variable, a silicon pressure sensor is used.
Silicon pressure sensor
In case of silicon pressure sensors, the pressure is transferred
via the separation diaphragm and the filling fluid to the
measuring diaphragm. The resistance values of the four piezo
resistors doped in the measuring diaphragm will change.
This pressure-proportional, internal output voltage is
converted via the electronic unit into a scaled electrical signal.
Depending on the model, the transmitter is connected to the
process by means of a spigot G ½ B (DIN EN 837-1), ½-
14 NPT male or female thread, flush diaphragm with special
thread G ½" for, e.g., ball valve connection or different
pressure sensors.
The pressure transmitter operates on the basis of two-wire
technology. The same lines are used for the operating voltage
(device-specific, see ‘Specification’ chapter) and the
standardized output signal. The electrical connection is
established via a cable entry or plug.

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 11
Fig. 4: 261G transmitter for pressure and level (example)
1 Process connection | 2 Separation diaphragm | 3 Filling fluid |
4 Measuring cell | 5 Pressure sensor |
6 Pushbutton for lower / upper range values |
7 Microprocessor-controlled electronics |
8 Output / Power supply
To measure the output signal and configure / calibrate the
pressure transmitter, an ampere meter must be connected
directly to the output circuit.
The lower and upper range values can be set via a pushbutton
on the electronic unit.
An optional fastener is available for attaching a stainless steel
tag so that the measuring points can be indicated.
The transmitter may also be equipped with an LCD indicator
that can be read from above (optional, can be retrofitted). With
the aid of this LCD indicator, the transmitter and its most
important functions / data can be fully configured using the
‘local’ control unit (four operating buttons on the indicator -see
‘Configuration’ chapter).

12 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
4Mounting
Before installing the transmitter, check whether the device
design meets the requirements of the measuring point from a
measurement technology and safety specifications point of
view. This applies in respect of the:
— Measuring range
— Overload resistance
— Temperature
— Explosion protection
— Operating voltage
The suitability of the materials must be checked as regards
their resistance to the media. This applies in respect of the:
— Process connection, separating diaphragm, etc.
In addition, the relevant directives, regulations, standards, and
accident prevention regulations must be observed (e. g.,
VDE/VDI 3512, DIN 19210, VBG, Elex V, etc.).
Measurement accuracy is largely dependent on correct
installation of the transmitter and, if applicable, the associated
impulse line(s).
As far as possible, the measuring setup should be free from
critical ambient conditions such as large variations in
temperature, vibrations, or shocks.
IMPORTANT (NOTICE)
If unfavorable ambient conditions cannot be
avoided for reasons relating to building structure,
measurement technology, or other issues, the
measurement quality may be affected.
(See ‘Specifications’ chapter).
If a remote seal with capillary tube is installed on the
transmitter, the additional operating instructions for remote
seals and the related data sheets must be observed.
4.1 Pressure transmitter
The pressure transmitter can be connected directly to the
shut-off valve. An angle bracket for wall or pipe mounting (2"
pipe) is also available as an accessory.
The pressure transmitter should be installed so that the
display and control unit are accessible during installation and
connection, as well as retrofitting.
Ideally, the pressure transmitter should be mounted in a
vertical position with the process connection pointing
downward to prevent subsequent zero position shifts.
IMPORTANT (NOTICE)
If the pressure transmitter is installed at an angle,
depending on the measuring range the filling fluid
exerts hydrostatic pressure on the measuring
diaphragm, resulting in a zero position shift.
The zero point must then be adjusted.
However, in principle the pressure transmitter can be used in
any mounting position. It is mounted by following the same
guidelines as for a manometer.
For mounting options with an angle bracket, see the section
"Specifications".

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 13
4.2 Sealing and screw connections
Connecting G ½ B spigot:
For sealing, a flat gasket must be used in accordance with DIN
EN 837-1.
NPT threaded connection:
Seal the threads with PTFE or another approved resistant
sealant.
Process connection with flush diaphragm:
Prior to mounting the device, install a welded connection or
tapped hole according to relevant soldering standards (for
process connection and welded connection dimensions, see
“Specifications”).
Process connection for ball valve:
An appropriate ball valve connection or weld-in sleeve is
required for mounting purposes. In this case, the seal is
formed by a cone at the outer end of the process connection
(metal/metal). For information on the weld-in sleeve, see
“Specifications”.
4.3 Moisture
Use suitable cables and tighten cable glands securely. The
transmitter can also be protected against the ingress of
moisture by routing the connecting cable downward before
securing it. This allows rain and condensation to drip down.
This is especially important for installation in outdoor areas
and rooms that are exposed to moisture (e.g., due to cleaning
processes) or on cooled or heated tanks.
Fig. 5: Steps for preventing the ingress of moisture

14 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
4.4 Measuring pipe
In order for the pipes to be laid correctly, the following points
must be observed:
— Keep the measuring pipe as short as possible and avoid
sharp bends.
— Lay the measuring pipe in such a way that no deposits
can accumulate in it. Gradients should not be less than
approx. 8 % (ascending or descending).
— The measuring pipe should be blown through with
compressed air or, better yet, flushed through with the
measuring medium before connection.
— Completely depressurize the measuring pipe if the medium
is a fluid.
— Lay the measuring pipe in such a way that gas bubbles
(when measuring fluids) or condensate (when measuring
gases) can flow back into the process line.
— When measuring steam, lay the measuring pipe in such a
way that hot steam cannot flow back into the process
connection (water trap, e.g., a water trap pipe that is filled
with water before installation).
— Check the tightness of the connection.

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 15
5Electrical connections
WARNING – Electrical dangers!
Observe the applicable regulations governing
electrical installation. Connections must only be
established in a dead-voltage state. The
transmitter has no switch-off elements. Therefore,
overcurrent protective devices, lightning
protection, or voltage disconnection options must
be provided at the plant.
Check that the existing operating voltage
corresponds to the voltage indicated on the name
plate.
The same lines are used for both the power
supply and output signal.
5.1 Cable connection
Depending on the model supplied, the electrical connection is
established via cable gland M16x1.5 (for diameters of
5 to 10 mm) or M20x1.5 (for diameters of 6 to 11 mm), a
threaded bore for cable gland 1/2-14 NPT, or via the Han 8U
plug, i.e., via the miniature plug connector M12 x 1 (see also
"Technical specification / Electrical connections").
The screw terminals are suitable for wiring cross-sections up
to 1.5 mm².
It is recommended that you strip approx. 30 … 35 mm
(1.18 … 1.38 inch) off the cable jacket.
Fig. 6: Stripped connecting cable
IMPORTANT (NOTICE)
After a period of several weeks, removing the screws
in the housing cover requires increased force. This is
not caused by the threads, but instead is due solely
to the type of seal.

16 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
Change from two to one column
5.2 Electrical connection in the cable connection area
Fig. 7
1 Pushbutton for lower/upper range values | 2 + Signal screw terminals for leads with cross-section of 0.5 … 1.5 mm2|
3 - Signal screw terminals for leads with a cross-section of 0.5 … 1.5 mm2| 4 Grounding / equipotential bonding terminal (optional) |
5 Cable entry | 6 Line load | 7 Grounding | 8 Handheld terminal | 9 Resistor (min. 250 Ω) |
10 Power supply / power supply unit | 11 Optional ground | 12 Receiver
application Permissible voltage range of power supply
Transmitter operated outside the potentially explosive atmosphere. 11 … 42 V
Transmitter operated inside the potentially explosive atmosphere. 11 … max. 30 V (intrinsically safe)
WARNING! Risk of explosion!
If, when using transmitters with type of protection "intrinsic safety", an ammeter is connected to the output circuit
or a modem is connected in parallel while there is a risk of explosion, the sums of the capacitances and
inductances of all circuits, including the transmitter (see EC-type-examination certificate) must be equal to or less
than the permissible capacitances and inductances of the intrinsically safe signal circuit (see EC-type-examination
certificate for the power supply unit).
Only passive or explosion-proof devices or indicators may be connected.

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 17
5.3 Electrical connection with plug
Fig. 8: Connection via plug connection
1 Harting Han 8D (8U) plug connection | 2 M12 x 1 miniature plug connector
Fig. 9: Pin assignment
1 Harting Han 8D (8U) socket insert for mating plug supplied (view of sockets) |
2 Mating plug (socket); not supplied | 3 M12 x 1 miniature plug (pins)
M10691
M12 x 1
26
1
2

18 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
Change from one to two columns
5.3.1 Assembly and connection of Han 8D (8U) socket
connector
The socket connector for connecting the cable is supplied
unassembled as an accessory for the transmitter.
IMPORTANT (NOTICE)
Please observe the specifications for the electrical
connection that have been supplied with the
connector.
Assembly is depicted in the figure below.
Fig. 10: Assembling the socket connector
1 Socket | 2 Contact | 3 Socket shell |
4 Gasket (can be cut) | 5 Thrust collar |
6 PG 11 pressure screw |
7 Cable (diameter 5 … 11 mm (0.20 ... 0.43 inch))
1.The contacts are crimped or soldered onto the cable ends
(wire cross-section of 0.75 … 1 mm2(AWG 18 … AWG
17)), from which approx. 1.5 … 2 cm (0.59 … 0.79 inch)
of the sleeve and approx. 8 mm (0.32 inch) of the
insulation have been stripped; they are then inserted into
the socket from the rear.
2.Slide the pressure screw, thrust collar, gasket, and socket
shell onto the cable in the order indicated before assembly
(you may have to adjust the gasket to fit the cable
diameter).
5.4 Protective conductor/Grounding (optional)
A terminal is available on the outside of the housing for
grounding (PE) the transmitter.
5.5 Communication setup
The transmitter can be operated via a modem, using a PC or
laptop. The modem can be connected to the transmitter in
parallel at any point in the signal circuit. Communication
between transmitter and modem occurs via AC signals that
are superimposed on the analog 4 ... 20 mA output signal.
This modulation occurs without averaging and does not,
therefore, affect the measuring signal.
Communication between transmitter and PC or laptop is only
possible if the signal circuit is set up as shown in the following
figure, “Communication mode: Point-to-point”. The resistance
between the connecting point for the FSK modem and the
power supply must be at least 250 Ω (including internal
resistance of the power supply unit). If this value is not
achieved within the context of normal installation, an additional
resistor must be used.
The ABB Contrans I supply modules with HART
communication already have a factory-installed, additional
resistor. Some of these modules offer the option of
communicating directly over the supply module in the
operating mode "FSK bus".
Power can be supplied by power supply units, batteries, or
power supplies; these must be designed to ensure that the
operating voltage UB of the transmitter always remains
between DC 11 V and 42 V (30 V for "Ex i").
In addition, the maximum current of 20 … 23.6 mA resulting
from overranging must be considered, depending on the
corresponding parameterization. This yields the minimum
value for US.
If additional signal receivers (e.g., indicators) are looped into
the signal circuit, their resistance must also be considered.

261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 19
Change from two to one column
Fig. 11: "Point-to-point" communication mode
1 Pressure transmitter | 2 Possible connecting points for a modem between A and B | 3 Power supply unit | 4 FSK modem
Fig. 12: "FSK bus" communication mode
1 FSK bus | 2 Supply module with HART isolation | 3 FSK modem
Change from one to two columns
5.6 Connecting cable
Communication between the transmitter and PC or laptop is
only possible if the cabling meets the following requirements:
The minimum wire diameter depends on the line length.
Line lengths up to 1,500 m: 0.51 mm
Line lengths above 1,500 m: 0.81 mm
The maximum line length is limited.
Dual-core cable: 3,000 m
Multi-core cable: 1,500 m
The actual possible line length of the electrical circuit depends
on the total capacitance and total line resistance, and can be
estimated using the following formula:
C
C
RxC
x
L
f 1000
6
1065 

L = Line length in m
R = Total line resistance in Ω (ohms)
C = Line capacitance in pF/m
Cf= Capacitance of the devices located in the circuit in pF
Avoid routing cables with other electrical cables (with inductive
load, etc.) or near large electrical equipment.
M10693
p
I + FSK
A
UBUS
+
+
+
– –
#
R
2600T
RS 232C
4
123
M10694
RS 232C
p
I + FSK
A
UBUS
+
++
#
R
2600T
4 & 20 mA
p
I + FSK
A
UBUS
+
++
#
R
2600T
4 & 20 mA
1
1
3
2
2

20 IM/261Gx/Ax-EN Rev. 08 | 261Gx, 261Ax
6Commissioning
6.1 General remarks
Once the pressure transmitter has been installed, it is put into
operation by switching on the operating voltage.
Check the following before switching on the operating voltage:
— Process connections
— Electrical connection
— Fill the impulse line and measuring chamber of the
measuring cell completely with measuring medium.
The transmitter can then be put into operation.
To do this, the shut-off valves must be actuated in the
following order (in the default setting, all valves are closed):
1. Open the discharge shut-off valve, if present.
2. Open the shut-off valve.
To put the transmitter out of operation, carry out the steps in
reverse order.
IMPORTANT (NOTICE)
In the case of pressure transmitters for absolute
pressure and measuring ranges of
≤ 40 kPa absolute, please note that the pressure
measuring cell has been overloaded over a long
period by the atmospheric pressure during
transport and storage. For this reason, you will
need to allow a starting time of approx. 3 hours
after commissioning until the sensor has
stabilized to such an extent that the specified
accuracy can be maintained.
When using transmitters with ‘intrinsic safety’ type of
protection, if an ampere meter is connected to the output
circuit or a modem is connected in parallel while an explosion
hazard is present, the sums of the capacitances and
inductances of all circuits, including the transmitter (see EC
type examination certificate) must be equal to or less than the
permissible capacitances and inductances of the intrinsically
safe signal circuit (see EC type examination certificate for the
power supply unit).
Only passive or explosion-proof test devices or display
instruments may be connected.
If the output signal stabilizes only slowly, it is likely that a large
damping time constant has been set on the transmitter.
6.2 Output signal
If the applied pressure is within the values indicated on the
name plate, the output current ranges between 4 und 20 mA.
If the pressure applied falls outside the set range, the output
current will be between 3.5 mA and 4 mA if the range is
undershot or between 20 mA and 23.6 mA if the range is
overshot (depending on the respective configuration).
Standard setting for normal operation
3.8 mA / 20.5 mA
A current that is < 4 mA or > 20 mA may also indicate that the
microprocessor has detected an internal error.
Standard setting for error detection
21 mA
The graphical user interface (DTM) can be used to diagnose
the error.
IMPORTANT (NOTICE)
A brief interruption in the power supply results in
initialization of the electronics (program restarts).
6.3 Write protection
Write protection prevents the configuration data from being
overwritten by unauthorized users. If write protection is
enabled, the "Lower Range Value / Upper Range Value”
pushbutton will be disabled.
It is still possible to read out the configuration data via optional
LCD indicator, handheld terminal or the graphical user
interface (DTM).
Write protection can be disabled via the graphical user
interface (DTM), a HART handheld terminal, or an optional
LCD indicator (see “Write protection” under “Configuration”).