Burkert 8791 User manual

Operating Instructions
Type 8791
Positioner SideControl BASIC
Electropneumatic positioner

We reserve the right to make technical changes without notice.
Technische Änderungen vorbehalten.
Sous réserve de modifications techniques.
© Bürkert Werke GmbH & Co. KG, 2009 – 2018
Operating Instructions 1802/08_EU-EN_00805664 / Original DE

3
Contents
1OPERATING INSTRUCTIONS ................................................................................................................8
1.1 Symbols........................................................................................................................................8
1.2 Denitionofterm/abbreviation..................................................................................................8
2AUTHORIZED USE .................................................................................................................................9
3BASIC SAFETY INSTRUCTIONS .........................................................................................................10
4GENERAL INFORMATION....................................................................................................................11
4.1 Contactaddresses.....................................................................................................................11
4.2 Warranty .....................................................................................................................................11
4.3 InformationontheInternet........................................................................................................11
5DESCRIPTION OF SYSTEM .................................................................................................................12
5.1 Generaldescription....................................................................................................................12
5.1.1 Features ......................................................................................................................12
5.1.2 Combination with valve types and mounting versions...............................................13
5.1.3 Optionally external position feedback with inductive proximity switch......................13
5.1.4 Overview of the mounting options..............................................................................14
6STRUCTURE.........................................................................................................................................15
6.1 Representation...........................................................................................................................15
7FUNCTION ............................................................................................................................................16
7.1 Functiondiagram .......................................................................................................................16
7.2 Functionofthepositioncontrol ................................................................................................17
7.3 Schematicrepresentationofthepositioncontrol ....................................................................18
7.4 Propertiesofthepositionersoftware........................................................................................19
7.4.1 Functions I ..................................................................................................................19
7.4.2 Functions II .................................................................................................................20
7.5 Interfacesofthepositioner ......................................................................................................21
8TECHNICAL DATA ................................................................................................................................22
8.1 Conformity..................................................................................................................................22
ElectropneumaticpositionerType8791
english
Type 8791

4
8.2 Standards ...................................................................................................................................22
8.3 Operatingconditions .................................................................................................................22
8.4 Mechanicaldata.........................................................................................................................22
8.5 Electricaldata ............................................................................................................................23
8.5.1 Electrical data 24 V DC...............................................................................................23
8.5.2 Electrical data with AS-Interface bus control (optional) .............................................23
8.6 Pneumaticdata ..........................................................................................................................24
8.7 Safetyendpositionsafterfailureoftheelectricalorpneumaticauxiliarypower...................25
8.8 Factorysettingsofthepositioner .............................................................................................26
8.8.1 Functions can be activated via DIP switches .............................................................26
8.8.2 Functions can be activated via communications software.........................................26
9OPERATING..........................................................................................................................................27
9.1 Safetyinstructions .....................................................................................................................27
9.2 Operatingstatus ........................................................................................................................... 27
9.3 Controlanddisplayelementsofthepositioner........................................................................27
9.3.1 Congurationofthekeys.............................................................................................. 28
9.3.2 Function of the DIP switches........................................................................................ 29
9.3.3 Display of the LEDs ......................................................................................................30
9.4 Errormessages............................................................................................................................. 31
9.4.1 Error messages in MANUAL and AUTOMATIC operating status ................................. 31
9.4.2 Error messages while the X.TUNE function is running ................................................31
10 FUNCTIONS.......................................................................................................................................... 32
10.1 Basicfunctions............................................................................................................................. 32
10.1.1 DIR.CMD -
Eectivesenseofdirectionofthepositionerset-pointvalue.....................................33
10.1.2 CUTOFF -
Sealing function for the positioner..............................................................................34
10.1.3 CHARACT -
Transfer characteristic between input signal
(position set-point value) and stroke ..........................................................................35
10.1.4 INPUT -
Enter the input signal..................................................................................................37
10.1.5 RESET -
Reset to factory settings.............................................................................................38
10.1.6 X.TUNE -
Automatic adjustment of the positioner to the relevant operating conditions............38
english
Type 8791

5
10.2 Additionalfunctions ..................................................................................................................... 39
10.2.1 DIR.ACTUATOR -
Eectivedirectionoftheactuator...............................................................................39
10.2.2 SPLITRANGE -
Signal split range ........................................................................................................40
10.2.3 X.LIMIT -
Limiting the mechanical stroke range.........................................................................41
10.2.4 X.TIME -
Limiting the control speed..........................................................................................42
10.2.5 X.CONTROL -
Parameterization of the positioner..............................................................................43
10.2.6 SAFE POSITION -
Denitionofthesafeposition .....................................................................................43
10.2.7 SIGNAL ERROR -
Congurationofsignallevelfaultdetection ...............................................................44
10.2.8 BINARY INPUT -
Activation of the binary input......................................................................................44
10.2.9 OUTPUT (optional) -
Congurationoftheanalogoutput.............................................................................45
11 ATTACHMENT AND ASSEMBLY ..........................................................................................................46
11.1 Safetyinstructions .....................................................................................................................46
11.2 AttachmenttoaproportionalvalvewithNAMURlinearactuators..........................................47
11.2.1 Attachment kit (IEC 534-6) for linear actuators (order no. 787215) ............................47
11.2.2 Installation...................................................................................................................48
11.2.3 Attaching mounting bracket .......................................................................................50
11.2.4 Aligning lever mechanism...........................................................................................51
11.3 Attachmenttoaproportionalvalvewithrotaryactuator .........................................................52
11.3.1 Attachment kit (VDI/VDE 3845) on rotary actuator (order no. 787338).......................52
11.3.2 Installation...................................................................................................................52
11.4 Remoteoperationwithexternalpositionsensor......................................................................55
11.4.1 Mounting accessories.................................................................................................55
11.4.2 Connection and start-up of the Remote-Sensor Type 8798 ......................................56
12 FLUID CONNECTION ...........................................................................................................................57
12.1 Safetyinstructions .....................................................................................................................57
13 ELECTRICAL CONNECTION................................................................................................................59
13.1 Safetyinstructions ....................................................................................................................59
english
Type 8791

6
13.2 Electricalconnectionwithcircularplug-inconnector.............................................................59
13.2.1 Designation of the circular plug-in connector ............................................................59
13.2.2 Pin assignment for input signals from the control centre (e.g. PLC) - M12,
8-pole plug..................................................................................................................60
13.2.3 Pin assignment for output signals to the control centre (e.g. PLC) - M12,
8-pole plug (required for analogue output option only) ..............................................60
13.2.4 Pin assignment for operating voltage -
M12, 8-pole circular plug-in connector .....................................................................60
13.3 Electricalconnectionwithcablegland .....................................................................................61
13.3.1 Designation of the screw-type terminals ....................................................................61
13.3.2 Connection of the screw-type terminals.....................................................................61
13.3.3 Terminal assignment for input signals from the control centre (e.g. PLC) ..................61
13.3.4 Terminal assignment for output signals to the control centre (e.g. PLC)
(required for analogue output option only) .................................................................62
13.3.5 Terminal assignment for operating voltage.................................................................62
13.3.6 Terminal assignment for external position sensor
(for remote model only)...............................................................................................62
14 START-UP .............................................................................................................................................63
14.1 Safetyinstructions .....................................................................................................................63
14.2 Specifyingthestandardsettings ..............................................................................................63
14.2.1 Running the automatic adjustment X.TUNE:.............................................................63
15 AS-INTERFACE.....................................................................................................................................65
15.1 AS-Interfaceconnection............................................................................................................65
15.4 Communicationsequencefortheversion
S-7.A.5prole............................................................................................................................66
15.5 LEDstatusdisplay(bus) ............................................................................................................67
15.6 ElectricalconnectionAS-Interface ...........................................................................................68
15.6.1 Safety instructions......................................................................................................68
15.6.2 Connection with M12 circular plug-in connector, 4-pole, male..................................68
16 SERVICE ...............................................................................................................................................69
17 ACCESSORIES .....................................................................................................................................69
17.1 Communicationssoftware......................................................................................................... 70
17.1.1 USB interface..............................................................................................................70
17.1.2 Download....................................................................................................................70
english
Type 8791

7
18 PACKAGING AND TRANSPORT ..........................................................................................................71
19 STORAGE .............................................................................................................................................71
20 DISPOSAL ............................................................................................................................................71
english
Type 8791

8
Operating Instructions
1 OPERATING INSTRUCTIONS
These operating instructions describe the entire life cycle of the device. Keep these instructions in a location
which is easily accessible to every user and make these instructions available to every new owner of the device.
Importantsafetyinformation.
Read the operating instruction carefully and thoroughly. Study in particular the chapters entitled “Basic
Safety Instructions” and “Authorized use”.
▶The operating instructions must be read and understood.
1.1 Symbols
DANGER!
Warnsofanimmediatedanger.
▶Failure to observe the warning may result in a fatal or serious injury.
WARNING!
Warnsofapotentiallydangeroussituation.
▶Failure to observe the warning may result in serious injuries or death.
CAUTION!
Warnsofapossibledanger.
▶Failure to observe this warning may result in a medium or minor injury.
NOTE!
Warnsofdamagetoproperty.
▶Failure to observe the warning may result in damage to the device or the equipment.
Indicatesimportantadditionalinformation,tipsandrecommendations.
Referstoinformationintheseoperatinginstructionsorinotherdocumentation.
▶Designates an instruction to prevent risks.
→Designates a procedure that must be carried out.
1.2 Denition of term / abbreviation
The term “device” used in these instructions always stands for the positioner type 8791.
In these instructions, the abbreviation “Ex” always refers to “potentially explosive”.
english
Type 8791

9
Authorized use
2 AUTHORIZED USE
IncorrectuseofthepositionerType8791canbedangeroustopeople,nearbyequipmentandthe
environment.
The device is designed for the open-loop control and closed-loop control of media.
▶Do not expose the device to direct sunlight.
▶Pulsatingdirectvoltage(rectiedalternatingvoltagewithoutsmoothing)mustnotbeusedassupply
voltage.
▶In the potentially explosion-risk area the positioner type 8791 may be used only according to the speci-
cationontheseparateExratingplate.Foruseobservetheadditionalinformationenclosedwiththe
device together with safety instructions for the explosion-risk area.
▶Devices without a separate Ex rating plate may not be used in a potentially explosive area.
▶Duringuseobservethepermitteddata,theoperatingconditionsandconditionsofusespeciedin
the contract documents and operating instructions, as described in chapter “8 Technical data” in this
manual and in the valve manual for the respective pneumatically actuated valve.
▶The device may be used only in conjunction with third-party devices and components recommended
and authorised by Bürkert.
▶In view of the wide range of possible application cases, check whether the positioner is suitable for the
specicapplicationcase.
▶Correct transportation, correct storage and installation and careful use and maintenance are essential
for reliable and faultless operation.
▶Use the positioner Type 8791 only as intended.
english
Type 8791

10
Basic Safety Instructions
3 BASIC SAFETY INSTRUCTIONS
These safety instructions do not make allowance for any
•contingencies and events which may arise during the installation, operation and maintenance of the devices.
•local safety regulations – the operator is responsible for observing these regulations, also with reference to
the installation personnel.
Riskofinjuryfromhighpressureintheequipment/device.
▶Beforeworkingonequipmentordevice,switchothepressureanddeaerate/drainlines.
Riskofelectricshock.
▶Beforeworkingonequipmentordevice,switchothepowersupplyandsecuretopreventreactivation.
▶Observe applicable accident prevention and safety regulations for electrical equipment.
Generalhazardoussituations.
To prevent injury, ensure that:
▶That the system cannot be activated unintentionally.
▶Installation and repair work may be carried out by authorised technicians only and with the appropriate
tools.
▶After an interruption in the power supply or pneumatic supply, ensure that the process is restarted in a
denedorcontrolledmanner.
▶The device may be operated only when in perfect condition and in consideration of the operating
instructions.
▶The general rules of technology apply to application planning and operation of the device.
To prevent damage to property on the device, ensure:
▶Donotsupplythesupplypressureconnectionofthesystemwithaggressiveorammablemediums.
▶Do not supply the supply pressure connection with any liquids.
▶Do not put any loads on the housing (e.g. by placing objects on it or standing on it).
▶Donotmakeanyexternalmodicationstothedevicehousings.Donotpaintthehousingpartsor
screws.
NOTE!
Electrostaticsensitivecomponents/modules.
Thedevicecontainselectroniccomponentswhichreactsensitivelytoelectrostaticdischarge(ESD).
Contactwithelectrostaticallychargedpersonsorobjectsishazardoustothesecomponents.Inthe
worstcasescenario,theywillbedestroyedimmediatelyorwillfailafterstart-up.
▶Observe the requirements in accordance with EN 61340-5-1 to minimise or avoid the possibility of dam-
age caused by sudden electrostatic discharge.
▶Also ensure that you do not touch electronic components when the power supply voltage is present.
english
Type 8791

11
General Information
4 GENERAL INFORMATION
4.1 Contact addresses
Germany
Contact address:
Bürkert Fluid Control Systems
Sales Center
Christian-Bürkert-Str. 13-17
D-74653Ingelngen
Tel. + 49 (0) 7940 - 10 91 111
Fax + 49 (0) 7940 - 10 91 448
E-mail: [email protected]
International
Contactaddressescanbefoundonthenalpagesoftheseprintedoperatinginstructions.
And also on the internet at:
www.burkert.com
4.2 Warranty
ThewarrantyisonlyvalidifthepositionerType8791areusedasintendedinaccordancewiththespecied
application conditions.
4.3 Information on the Internet
The operating instructions and data sheets for Type 8791 can be found on the internet at:
www.burkert.com
english
Type 8791

12
Description of System
5 DESCRIPTION OF SYSTEM
5.1 General description
The positioner Type 8791 is a digital, electropneumatic positioner for pneumatically actuated proportional
valves. The device incorporates the main function groups
- Position sensor
- Electropneumatic control system
- Microprocessor electronics
The position sensor measures the current positions of the proportional valve.
The microprocessor electronics continuously compare the current position (actual value) with a set-point
positionvaluespeciedviathestandardsignalinputandsuppliestheresulttothepositioner.
Ifthereisacontroldierence,theelectropneumaticcontrolsystemcorrectstheactualpositionaccordingly.
5.1.1 Features
•Version
Positioner:
The position of the actuator is regulated according to the position set-point value. The position set-point
valueisspeciedbyanexternalstandardsignalorviaeldbus.
•Positionsensor
- internal high resolution conductive potentiometer or
- external non-contact, non-wearing position sensor (remote).
•Microprocessor-controlledelectronics
for signal processing, control and valve control.
•Controlmodule
The unit is operated via 2 keys and 4 DIP switches.
3 LEDs indicate the status of the unit.
•Controlsystem
The control system consists of 2 solenoid valves and 4 diaphragm reinforcers. In single-acting actuators
the working connection 2 must be sealed with a threaded plug.
•Feedback(optional)
The feedback is implemented either via 2 proximity switches or via an 4 – 20 mA output.
The operator can change the proximity switches or limit positions via control lugs.
•Pneumaticinterfaces
Internal thread G1/4“
•Electricalinterfaces
Circular plug-in connector or cable gland
•Communicationsinterface
Forcongurationandparameterization
•Housing
Plastic-coated aluminium housing with hinged cover and captive screws.
english
Type 8791

13
Description of System
•Mounting
on linear actuator according to NAMUR recommendation (DIN IEC 534-6) or on rotary actuator according
to VDI/VDE 3845.
•Optional
Remote version for DIN rail mounting or for mounting bracket
5.1.2 Combination with valve types and mounting versions
ThepositionerTypes8791canbemountedondierentproportionalvalves.Forexampleonvalveswith
linear (piston), membrane or rotary actuator. The actuators can be single-acting or double-acting.
•For single-acting actuators, only one chamber is aerated and deaerated during actuation. The generated
pressure works against a spring. The piston moves until there is an equilibrium of forces between com-
pressive force and spring force. To do this, one of the two air connections must be sealed with a threaded
plug.
•For double-acting actuators the chambers on both sides of the piston are pressurised. In this case, one
chamber is aerated when the other one is deaerated and vice versa. In this design, no spring is installed in
the actuator.
TwobasicdeviceversionsareoeredforthepositionerType8791;theydierintheattachmentoptionand
in the position sensor.
DeviceversionNAMUR:
An internal position sensor is used which is designed as a rotary potentiometer. The positioner is attached
directly to the actuator.
DeviceversionRemote:
An external position sensor (linear or rotative) via a digital interface. The positioner is attached to a wall
either with a DIN rail or with a mounting bracket (remote design).
5.1.3 Optionally external position feedback with inductive proximity
switch
Thepositionertype8791canbettedwithanexternalpositionfeedback(seedatasheet/accessories).
The installation and the setting are described in the installation instructions which are enclosed with the
external position feedback.
The installation instructions can also be found on the Internet.
www.burkert.com →Type 8791
english
Type 8791

14
Description of System
5.1.4 Overview of the mounting options
Mounting NAMUR on
rotary actuator
Mounting NAMUR
with mounting
bracket
on a linear actuator
Remote mounting
with mounting
bracket
Remote mounting
with DIN rail
Table 1: Overview of the mounting options
english
Type 8791

15
Structure
6 STRUCTURE
The positioner Type 8791 consist of the micro-processor controlled electronics, the position sensor and the
control system.
The appliance is designed using three-wire technology. The unit is operated via 2 keys and 4 DIP switches.
3LEDsindicatethedierentstatusesoftheunit.
The pneumatic control system for single-acting and double-acting actuators consists of 2 solenoid valves.
6.1 Representation
Mechanical position indicator
Display module with 3 LEDs
Working connection 2
(connection: A2)
Supply pressure connection 1.4 – 7 bar
(connection: P)
Working connection 1
(connection: A1)
Air exhaust connection/
airexhaustlter
Internal position sensor
Axle for position sensor
Cable gland
Electronic module
Control system
Pressure-relief valve
Figure 1: Structure, positioner type 8791
english
Type 8791

16
Function
7 FUNCTION
7.1 Function diagram
Diagram illustrating single-acting actuator
*Control system
1: Aeration valve
2: Bleed valve
Compressed-air
supply
Position
sensor
Positioner
Control
system*
1
2
Position set-
point value
Exhaust air
PositionerType8791 Controlvalvewith
single-actingactuator
Actual position
Figure 2: Function diagram, positioner type 8791
Theremotedesignhasthepositionsensorsituatedoutsidethepositionerdirectlyonthepropor-
tionalvalveandisconnectedtothelatterbyacable.
english
Type 8791

17
Function
7.2 Function of the position control
The position sensor records the current position (POS) of the pneumatic actuator. The positioner compares this
actual position value with the set-point value (CMD)whichisastandardsignal.Ifthereisacontroldierence
(Xd1), the actuator is aerated and deaerated via the control system. In this way the position of the actuator is
changeduntilcontroldierenceis0.Z1representsadisturbancevariable.
Valve opening
Control
valve
Control system
Solenoid
valves
Position sensor
PositionerPosition set-
point value
CMD Xd1 B1
E1
PK
Z1
POS
Position control circuit
+-
Figure 3: Signal ow plan of positioner
english
Type 8791

18
Function
7.3 Schematic representation of the position control
4 – 20 mA (Default setting) 0 – 20 mA
DIR.CMD SPLTRNG * CHARACT CUTOFF X.TIME *
DIR.ACT * X.LIMIT *
X.CONTROL DBND
POS
CMD
INP
POS CMD TEMP INPUT
* Can be activated with communica-
tions software only
Figure 4: Schematic representation of position control
english
Type 8791

19
Function
7.4 Properties of the positioner software
7.4.1 Functions I
•Activation via DIP switches
•Parameter setting via communications software
Additionalfunction Eect
Sealing function
CUTOFF
Valve closes tight outside the control range. Speci-
cationofthevalue(as%)fromwhichtheactuator
iscompletelydeaerated(when0%)oraerated(when
100%)
(see chapter entitled “9.3.2 Function of the DIP
switches”).
Correction line to adjust the operating
characteristic
CHARACT
The operating characteristic may be linearized
(see chapter entitled “9.3.2 Function of the DIP
switches”).
Eectivesenseofdirectionofthecontroller
nominal value
DIR.CMD 1)
Reversaloftheeectivesenseofdirectionoftheset-
point value (see chapter entitled “9.3.2 Function of the
DIP switches”).
Table 2: Functions I
1) DIR.CMD can be accessed in read-only mode via the communications software.
This function is set via the DIP switch only, as the function has no other parameters.
english
Type 8791

20
Function
7.4.2 Functions II
•Activation and parameter setting via communications software
Additionalfunction Eect
Standard signal for set-point value
INPUT
Select set-point value standard signal.
Eectivedirectionoftheactuator
DIR.ACTUATOR
Assignment of the aeration state of the actuator
chamber to the actual position.
Signal split range
SPLITRANGE
Standardsignalas%forwhichthevalverunsthrough
the entire mechanical stroke range.
Mechanical stroke range limit
X.LIMIT
Limit the mechanical stroke range.
Opening and closing time
X.TIME
Limit the control speed.
Positioner
X.CONTROL
Parameterize the positioner.
Safety position
SAFEPOSITION
Denitionofthesafetyposition.
Signal level fault detection
SIGNAL ERROR
Congurationofsignallevelfaultdetection.
Binary input
BINARY INPUT
Congurationofthebinaryinput.
Analog output
OUTPUT
Congurationoftheanalogoutput(optional).
Reset
RESET
Reset to factory settings.
Table 3: Functions II
english
Type 8791