Burkert 8791 REV.2 User manual

Operating instructions
Type 8791 REV.2
Positioner SideControl BASIC
Electro-pneumatic positioner
STATUS
COM

We reserve the right to make technical changes without notice.
Technische Änderungen vorbehalten.
Sous réserve de modifications techniques.
© Bürkert Werke GmbH & Co. KG, 2009–2022
Operating Instructions 2211/04_ENen_00815310/Original DE

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Content
1ABOUT THESE INSTRUCTIONS............................................................................................................8
1.1 Symbols........................................................................................................................................8
1.2 Denitionofterms........................................................................................................................9
1.3 Firmwaremodications ...............................................................................................................9
2INTENDED USE ....................................................................................................................................10
3BASIC SAFETY INSTRUCTIONS .........................................................................................................11
4GENERAL NOTES.................................................................................................................................12
4.1 Contactaddress.........................................................................................................................12
4.2 Warranty .....................................................................................................................................12
4.3 InformationontheInternet........................................................................................................12
5PRODUCT DESCRIPTION....................................................................................................................13
5.1 Generaldescription....................................................................................................................13
5.1.1 Characteristics............................................................................................................13
5.1.2 Combination with valve types and mounting variants................................................14
5.1.3 Optional external position feedback unit with inductive proximity switch..................14
5.1.4 Overview of mounting options....................................................................................15
6STRUCTURE.........................................................................................................................................16
6.1 Illustration...................................................................................................................................16
7FUNCTION............................................................................................................................................17
7.1 Functionaldiagram ....................................................................................................................17
7.2 Positioncontrolfunction............................................................................................................18
7.2.1 Schematic presentation of the position control..........................................................19
7.2.2 Functions of the positioner software ..........................................................................20
7.3 Positionerinterfaces .................................................................................................................22
8TECHNICAL DATA ................................................................................................................................23
8.1 Standardsanddirectives...........................................................................................................23
8.2 Operatingconditions .................................................................................................................23
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8.3 Mechanicaldata.........................................................................................................................23
8.4 Typelabel ...................................................................................................................................24
8.5 Electricaldata ............................................................................................................................24
8.5.1 Electricaldata,withouteldbuscommunication........................................................24
8.5.2 Electrical data, IO-Link ...............................................................................................25
8.5.3 Electrical data, büS.....................................................................................................25
8.6 Pneumaticdata ..........................................................................................................................26
8.7 Safetyendpositionsafterfailureoftheelectricalorpneumaticauxiliarypower...................27
8.8 Positionerfactorysettings.........................................................................................................28
8.8.1 Functions that can be activated via DIP switch.......................................................... 28
8.8.2 Functions that can be activated via the communication software .............................28
9OPERATION..........................................................................................................................................29
9.1 Safetyinstructions .....................................................................................................................29
9.2 Operatingstate .............................................................................................................................29
9.3 Operatinganddisplayelementsofthepositioner ...................................................................29
9.3.1 Assignment of the keys ................................................................................................ 30
9.3.2 DIP switch function....................................................................................................... 31
9.3.3 LED display................................................................................................................... 32
9.3.4 Status indicator............................................................................................................. 32
9.3.5 Status LED, green.......................................................................................................34
9.4 Errornotications .........................................................................................................................35
9.4.1 Noticationsondevicestatus:Outofspecication..................................................... 35
9.4.2 Messages:Actuatorismovingtosafetyposition......................................................... 35
10 FUNCTIONS..........................................................................................................................................37
10.1 Basicfunctions.............................................................................................................................37
10.1.1 DIR.CMD -
Inversion of direction of the positioner set-point value ..............................................38
10.1.2 CUTOFF -
Sealing function for the positioner..............................................................................39
10.1.3 CHARACT -
Characteristic correction between the input signal (position set-point value) and stro-
ke ................................................................................................................................40
10.1.4 INPUT -
Inputofstandardsignal(onlyvariantwithouteldbuscommunication) ....................42
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10.1.5 RESET/FACTORY RESET -
Reset device to factory settings .................................................................................43
10.1.6 X.TUNE -
Automatic calibration of the positioner to the respective operating conditions .........43
10.2 Auxiliaryfunctions ........................................................................................................................44
10.2.1 DIR.ACT -
Actuator inversion of direction....................................................................................45
10.2.2 SPLTRNG -
Signal split range ........................................................................................................46
10.2.3 X.LIMIT -
Stroke limitation..........................................................................................................47
10.2.4 X.TIME -
Actuating time limit .....................................................................................................48
10.2.5 X.CONTROL -
control parameter of the positioner ............................................................................49
10.2.6 SAFEPOS -
Denitionofsafetyposition ........................................................................................49
10.2.7 SIG.ERROR -
Conguringthecablebreakdetection(onlyforvariantswithouteldbuscommunica-
tion).............................................................................................................................50
10.2.8 BINARY.IN -
Conguringthedigitalinput(onlyforvariantswithouteldbuscommunication).......50
10.2.9 OUTPUT (variant) -
Conguringtheanalogueoutput(onlyforvariantswithouteldbus
communication) ..........................................................................................................51
10.2.10 Setting LED operation mode, device status...............................................................51
11 MOUNTING AND INSTALLATION ........................................................................................................52
11.1 Safetyinstructions .....................................................................................................................52
11.2 MountingonacontinuousvalvewithlinearactuatoraccordingtoNAMUR ..........................53
11.2.1 Attachment kit (in accordance with IEC 534-6) on linear actuators
(order number 787215) ............................................................................................... 53
11.2.2 Installation...................................................................................................................54
11.2.3 Attaching the mounting bracket .................................................................................56
11.2.4 Aligning the lever mechanism.....................................................................................57
11.3 Mountingonacontinuousvalvewithrotaryactuator..............................................................58
11.3.1 Attachment kit (in accordance with VDI/VDE 3845) on rotary actuator
(Order number 787338)...............................................................................................58
11.3.2 Installation...................................................................................................................58
11.4 Remoteoperationwithexternalpositionsensor......................................................................61
11.4.1 Attachment accessories .............................................................................................61
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11.4.2 Connection and start-up of the remote sensor Type 8798.........................................62
12 PNEUMATIC CONNECTION.................................................................................................................63
12.1 Safetyinstructions .....................................................................................................................63
13 ELECTRICAL INSTALLATION WITHOUT FIELDBUS COMMUNICATION...........................................65
13.1 Safetyinstructions .....................................................................................................................65
13.2 Electricalinstallationwithcircularplug-inconnector ..............................................................65
13.2.1 Designation of circular plug-in connector M12, 8-pin ................................................65
13.2.2 Pin assignment for input signals from control centre (e.g. PLC) ................................66
13.2.3 Pin assignment for the output signals to the control centre (PLC, for example), only
for the analogue output variant ..................................................................................66
13.2.4 Pin assignment for operating voltage.........................................................................67
13.3 Electricalinstallationwithcablegland......................................................................................67
13.3.1 Designation of screw-type terminals ..........................................................................67
13.3.2 Connection of terminals..............................................................................................67
13.3.3 Terminal assignment for input signals from control centre (e.g. PLC) ........................68
13.3.4 Terminal assignment for the output signals to the control centre (PLC, for example),
only for analogue output variant.................................................................................68
13.3.5 Terminal layout for operating voltage ........................................................................69
13.3.6 Terminal assignment for external position sensor
(only for remote variant) ..............................................................................................69
14 ELECTRICALINSTALLATION,IO-LINK................................................................................................70
14.1 Connectionassignmentforexternalpositionsensor
(onlyforremotevariant).............................................................................................................70
15 ELECTRICAL INSTALLATION, BÜS .....................................................................................................72
15.1 Connectionassignmentforexternalpositionsensor
(onlyforremotevariant).............................................................................................................72
16 START-UP .............................................................................................................................................73
16.1 Safetyinstructions .....................................................................................................................73
16.2 Deningbasesettings ...............................................................................................................73
16.2.1 Execute the X.TUNE automatic adjustment...............................................................73
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16.3 SetdevicewithBürkertCommunicator ....................................................................................74
16.3.1 Connecting the IO-Link device to the Bürkert Communicator ...................................74
16.3.2 Connecting the büS device to the Bürkert Communicator ........................................75
17 IO-LINK .................................................................................................................................................76
17.1 Information,IO-Link ...................................................................................................................76
17.2 Technicaldata,IO-Link ..............................................................................................................76
17.3 Conguringtheeldbus ............................................................................................................76
18 BÜS.......................................................................................................................................................77
18.1 Information,büS.........................................................................................................................77
18.2 Conguringtheeldbus ............................................................................................................77
19 MAINTENANCE ....................................................................................................................................78
20 ACCESSORIES.....................................................................................................................................78
20.1 Communicationsoftware...........................................................................................................78
21 PACKAGING,TRANSPORT,DISPOSAL ..............................................................................................79
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About these instructions
1 ABOUT THESE INSTRUCTIONS
The operating instructions describe the entire life cycle of the device.
→Keep these instructions ready to hand at the operating site.
Importantsafetyinformation!
▶Read these instructions carefully.
▶Above all, observe the safety instructions, intended use and operating conditions.
▶Persons who work on the device must read and understand these instructions.
1.1 Symbols
DANGER!
Warnsofanimmediatedanger.
▶Failure to observe these instructions will result in death or serious injuries.
WARNING!
Warnsofapotentiallyhazardoussituation.
▶Failure to observe these instructions may result in serious injuries or death.
CAUTION!
Warnsofapotentialdanger.
▶Failure to observe these instructions may result in moderate or minor injuries.
WARNING!
Warnsofdamage.
▶Failure to observe these instructions may result in damage to the device or the system.
Indicatesimportantadditionalinformation,tipsandrecommendations.
Referstoinformationintheseinstructionsorinotherdocumentation.
▶Designates instructions to avoid a danger.
→Highlights a procedure which you must carry out.
Designates a result.
Menu Marks a user interface text.
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About these instructions
1.2 Denition of terms
Intheseinstructions,theterm“device”referstothefollowingtypesofdevices:
Type8791positionerREV.2
The term “büS” (Bürkert system buS) used in this manual stands for the communication buS developed by
Bürkert, based on the CANopen protocol.
The abbreviation “Ex” used in these instructions always stands for “potentially explosive atmosphere”.
1.3 Firmware modications
Fromrmware
version
Modications
A.1.6 Informationfor“Valvepositioninbetween”changedfrom“LEDo”to“LEDlightswhite”
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Intended use
2 INTENDED USE
ThePositionertype8791REV.2hasbeendesignedformountingonpneumaticactuatorsofprocess
valvestocontroltheowofmedia.Thepermittedmediaarelistedinthe"Technicaldata".
▶Use the device only as intended. Non-intended use of the device may be dangerous to people, nearby
equipment and the environment.
▶Prerequisites for safe and trouble-free operation are correct transportation, correct storage, installation,
start-up, operation and maintenance.
▶To use the device, observe the permitted data, operating conditions and application conditions. These
specicationscanbefoundinthecontractdocuments,theoperatinginstructionsandontheTypelabel.
▶Use the device only in conjunction with third-party devices and components recommended or approved
by Bürkert.
▶When used outdoors, protect the device against adverse weather conditions.
▶In potentially explosive areas, only use devices that are approved for these areas. These devices are
identiedbyaseparate“Ex”typelabel.Beforeuse,notetheinformationontheseparateExtypelabel
and the Ex additional instructions or the separate Ex operating Instructions.
▶DonotusepulsatingDCvoltage(rectiedACvoltagewithoutsmoothing)asthesupplyvoltage.
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Basic safety instructions
3 BASIC SAFETY INSTRUCTIONS
These safety instructions do not take into account any unforeseen circumstances and events which occur
during installation, operation and maintenance.
Theoperatorisresponsibleforobservingthelocation-specicsafetyregulations,alsowithreferenceto
personnel.
DANGER!
Riskofinjuryduetohighpressureandanyescapingmedia.
▶Switchothepressurebeforeworkingonthedeviceorsystem.Ventoremptythelines.
DANGER!
Riskofinjuryfromelectricshock.
▶Switchothepowersupplybeforeworkingonthedeviceorsystem.Secureagainstreactivation.
▶Observe the applicable accident prevention and safety regulations for electrical devices.
Topreventinjuries,observethefollowing:
▶Ensure that the device or system cannot be activated unintentionally.
▶Only trained technicians may perform installation and maintenance work.
▶Perform installation and maintenance work using suitable tools only.
▶Do not make any changes to the device and do not subject it to mechanical stress.
▶Use the device only when it is in perfect condition and in accordance with the operating instructions.
▶Observe the general rules of technology.
▶Install the device according to the regulations applicable in the respective country.
▶Do not feed any aggressive or combustible media into the connections of the device.
▶Do not feed any liquids into the device’s connections.
▶Onlyrestarttheprocessinacontrolledmannerfollowingdisruptions.Observesequence:
1. Apply supply voltage or pneumatic supply.
2. Pressurise with medium.
▶Observe the intended use.
WARNING!
Electrostaticallysensitivecomponentsandassemblies.
Thedevicecontainselectroniccomponentsthataresusceptibletotheeectsofelectrostatic
discharging(ESD).Componentsthatcomeintocontactwithelectrostaticallychargedpersonsor
objectsareatrisk.Intheworst-casescenario,theywillbedestroyedimmediatelyorwillfailafter
start-up.
▶Observe requirements of EN 61340-5-1 for minimising or avoiding the possibility of damage caused by
sudden electrostatic discharge.
▶Also ensure that you do not touch the electronic components when the voltage is applied.
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General notes
4 GENERAL NOTES
4.1 Contact address
Germany
Bürkert Fluid Control System
Sales Centre
Christian-Bürkert-Str. 13-17
D-74653Ingelngen
Tel. + 49 (0) 7940 - 10 91 111
Fax + 49 (0) 7940 - 10 91 448
Email:[email protected]
International
The contact addresses can be found on the back pages of the printed operating instructions.
AlsoontheInternetat:
country.burkert.com
4.2 Warranty
ApreconditionforthewarrantyisthattheType8791positionerisusedasintendedandthatthespecied
conditions of use are taken into account.
4.3 Information on the Internet
OperatinginstructionsanddatasheetsfortheType8791canbefoundontheInternetat:
country.burkert.com
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Product description
5 PRODUCT DESCRIPTION
5.1 General description
The Type 8791 positioner is a digital electro-pneumatic positioner for pneumatically actuated continuous
valves. The device contains the main functional groups
- Position sensor
- Pilot valve system (electro-pneumatic actuating system)
- Microprocessor electronics
The position sensor measures the current positions of the continuous valve.
The microprocessor electronics continuously compare the current position (actual value) with a position set-
point value prescribed by the standard signal input and supply the positioner with the result.
Ifthereisacontroldierence,thepilotvalvesystemcorrectstheactualposition.
5.1.1 Characteristics
•Variant
The positioner is available with position control function.
The position of the actuator is controlled according to the position set-point value. The position set-point
valueisspeciedbyanexternalstandardsignal(orviaeldbus).
•Positionsensor
- Internal high-resolution conductive plastic potentiometer or
- External contactless wear-free position sensor (remote).
•Microprocessor-controlledelectronicsassembly
for signal processing, closed-loop control and valve control.
•Controlmodule
The device is controlled with two keys and four DIP switches.
Two LEDs (one RGB-LED for the device status and one green LED for the status of the communication
interface)enabledierentdevicestatusestobedisplayed.
•Pilotvalvesystem
Theactuatingsystemconsistsoftwosolenoidvalvesandfourdiaphragmampliers.Forsingle-acting
actuators, working port 2 must be sealed with a threaded plug.
•Positionfeedback
The position of the valve can be transferred either via 2 proximity switches or via a 0/4...20 mA output
(variantwithouteldbuscommunication)ortransferreddigitallyviaaeldbuscommunication(for
example, büS, IO-Link) to the PLC. The proximity switches or basic positions can be changed by the user
using control vanes.
•Pneumaticinterfaces
Internal thread G1/4“
•Electricalinterfaces
(circular plug-in connector or cable gland)
•Communicationinterface
To exchange process data and for configuration and parameterisation
•Housing
Plastic-coated aluminium housing with hinged cover and captive screws.
The housing of the positioner is protected against internal pressure that is too high, for example following
leakages, by a pressure limiting valve.
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Product description
•Mounting
On linear actuator in accordance with NAMUR recommendation (DIN IEC 534-6) or on rotary actuator in
accordance with VDI/VDE 3845.
•Optional
Remote variant for standard rail assembly or for mounting brackets
5.1.2 Combination with valve types and mounting variants
The positioner Type 8791 can be attached to various continuous valves. For example, to valves with piston,
diaphragm or rotary actuators. The actuators can be single- or double-acting.
•In single-acting actuators, only one chamber is aerated and vented. The pressure generated works against
a spring. The piston moves until a force equilibrium is reached between the compressive force and spring
force. For this, one of the two air connections is sealed with a threaded plug.
•For double-acting actuators, the chambers on both sides of the piston are pressurised. The aeration of
one chamber aerates the other chamber and vice versa. No spring is installed in the actuator for this
variant.
ForthepositionerType8791,twobasicdevicevariantsareoered,whichdierintermsoftheattachment
option and the position sensor.
NAMURdevicevariant:
An internal device position sensor is used which is designed as a rotary potentiometer. The positioner is
mounted directly on the actuator.
Remotedevicevariant:
An external position sensor (linear or rotative) is connected via a digital interface.
The positioner is either mounted with a standard rail or with a mounting bracket on a wall (remote variant)
for this.
5.1.3 Optional external position feedback unit with inductive
proximity switch
ThepositionerType8791canbettedwithanexternalpositionfeedbackunit(seedatasheetinthe
accessory).
The installation and settings are described in the assembly instructions enclosed with the external position
feedback unit.
The assembly instructions can also be found on the Internet.
country.burkert.com →Type 8791
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Product description
5.1.4 Overview of mounting options
NAMUR mounting on
rotary actuator
NAMUR mounting
with
mounting bracket on
a linear actuator
Remote mounting
with fastening
bracket
Remote mounting on
standard rail
Table 1: Overview of mounting options
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Structure
6 STRUCTURE
The positioner Type 8791 consists of the microprocessor-controlled electronic mechanism, the position sensor
and the pilot valve system.
The device is controlled with two keys and four DIP switches. Two LEDs (one RGB-LED for the device status and
onegreenLEDforthestatusofthecommunicationinterface)enabledierentdevicestatusestobedisplayed.
The pilot valve system for single- and double-acting actuators consists of two solenoid valves.
6.1 Illustration
Mechanical position indicator
Display module with two LEDs
Working port 2
(Connection:A2)
Pressure port 1.4...7 bar
(Connection:P)
Working port 1
(Connection:A1)
Exhaust port/
Exhaustlter
Internal position sensor
Shaft for position sensor
Cable gland
Electronic module
Pilot valve system
Pressure-relief valve
Fig. 1: Structure, positioner Type 8791
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Function
7 FUNCTION
7.1 Functional diagram
Exemplary presentation with single-acting actuator
*Pilot valve system
1:Aerationvalve
2:Exhaustvalve
Compressed air
supply
Position
sensor
Positioner
Pilot valve
system*
1
2
Position
set-point
value
Exhaust air
PositionerType8791 Valve(proportionalvalve)with
single-actingactuator
Actual position
Fig. 2: Positioner Type 8791 functional diagram
Fortheremotevariant,thepositionsensorisconnecteddirectlytothevalveoutsideoftheposi-
tionerandisconnectedtothisusingacable.
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Function
7.2 Position control function
The position sensor records the current position (POS) of the pneumatic actuator. This actual position is
compared by the positioner to theset-point value (CMD)speciedasthestandardsignal.Ifthereisacontrol
dierence(Xd1),theactuatorisaeratedandventedviathepilotvalvesystem.Inthisway,thepositionofthe
actuatorischangeduptocontroldierence0.Z1isadisturbance.
Valve opening
ValvePilot valve
system
Position sensor
PositionerPosition
set-point
value
CMD Xd1 B1
E1
PK
Z1
POS
Position control loop
+-
Fig. 3: Positioner signal ow plan
Type 8791, REV.2
english

19
Function
7.2.1 Schematic presentation of the position control
büS, IO-Link 4...20mA(factorysetting) 0...20mA
DIR.CMDSPLTRNG1) CHARACT CUTOFF X.TIME1)
DIR.ACT1) X.LIMIT1)
X.CONTROL DBND
POS
CMD*
CMD
1) Can only be activated with com-
munication software
Fig. 4: Schematic presentation of the position control
Type 8791, REV.2
english

20
Function
7.2.2 Functions of the positioner software
Basicfunctions
•Activation with DIP switch
•Parameter setting with communication software
Function Eect
Sealing function
CUTOFF
Valvesealsoutsideofthecontrolrange.Speci-
cation of the value (in %) from which the actuator is
completely vented (at 0%) or aerated (at 100%) (see
Chapter “9.3.2 DIP switch function”).
Characteristic correction
CHARACT
Linearization of the operating characteristic can be
executed (see Chapter “9.3.2 DIP switch function”).
Inversion of direction set-point value
DIR.CMD
Reversaloftheeectivedirectionoftheset-point
value
(see Chapter “9.3.2 DIP switch function”).
Table 2: Basic functions
Basicfunctions
•Activation with keys or communication software
Function Eect
Standard signal2)
INPUT
Selection of the standard set-point value signal
Automatic calibration of the positioner
X.TUNE
Factory reset
RESET
Resetting to factory settings
Table 3: Basic functions
2) Can only be set with communication software.
Only for variants without eldbus communication.
Type 8791, REV.2
english