Burkert 8791 REV.2 Operating Instructions Manual
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Burkert 8791 REV.2 Operating Instructions Manual

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

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Summary of Contents for Burkert 8791 REV.2

  • Page 1 Type 8791 REV.2 Positioner SideControl BASIC Electro-pneumatic positioner STATUS Operating instructions...
  • Page 2 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...

  • Page 3: Table Of Contents

    Type 8791, REV.2 Electro-pneumatic positioner Type 8791 REV.2 ontent ABOUT THESE INSTRUCTIONS ......................8 Symbols ............................8 1.2 Definition of terms ........................9 1.3 Firmware modifications .......................9 INTENDED USE ............................10 BASIC SAFETY INSTRUCTIONS ......................11 GENERAL NOTES..........................12 4.1 Contact address .........................12 4.2 Warranty .............................12 4.3 Information on the Internet ......................12 PRODUCT DESCRIPTION ........................13 5.1 General description ........................13 5.1.1 Characteristics ......................13 5.1.2...
  • Page 4 Type 8791, REV.2 8.3 Mechanical data .........................23 8.4 Type label ...........................24 8.5 Electrical data ..........................24 8.5.1 Electrical data, without fieldbus 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 OPERATION ............................29...
  • Page 5 Type 8791, REV.2 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...
  • Page 6 Type 8791, REV.2 11.4.2 Connection and start-up of the remote sensor Type 8798 .........62 PNEUMATIC CONNECTION .........................63 12.1 Safety instructions ........................63 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.
  • Page 7 Type 8791, REV.2 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 IO-LINK ..............................76 17.1 Information, IO-Link ........................76 17.2 Technical data, IO-Link ......................76 17.3 Configuring the fieldbus ......................76 BÜS ...............................77 18.1 Information, büS .........................77 18.2 Configuring the fieldbus ......................77 MAINTENANCE ............................78 ACCESSORIES .............................78...

  • Page 8: About These Instructions

    Type 8791, REV.2 About these instructions 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. ▶...

  • Page 9: Definition Of Terms

    Type 8791, REV.2 About these instructions Definition 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”. Firmware modifications From firmware Modifications...

  • Page 10: Intended Use

    Type 8791, REV.2 Intended use INTENDED USE The Positioner type 8791 REV.2 has been designed for mounting on pneumatic actuators of process valves to control the flow 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.

  • Page 11: Basic Safety Instructions

    Type 8791, REV.2 Basic safety instructions 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-specific safety regulations, also with reference to personnel. DANGER! Risk of injury due to high pressure and any escaping media. ▶ Switch off the pressure before working on the device or system. Vent or empty the lines. DANGER! Risk of injury from electric shock. ▶ Switch off 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: ▶...

  • Page 12: General Notes

    Christian-Bürkert-Str. 13-17 D-74653 Ingelfingen Tel. + 49 (0) 7940 - 10 91 111 Fax + 49 (0) 7940 - 10 91 448 Email: info@burkert.com International The contact addresses can be found on the back pages of the printed operating instructions. Also on the Internet at: country.burkert.com...

  • Page 13: Product Description

    Type 8791, REV.2 Product description PRODUCT DESCRIPTION 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.

  • Page 14: Combination With Valve Types And Mounting Variants

    Optional external position feedback unit with inductive proximity switch The positioner Type 8791 can be fitted 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. → Type 8791 country.burkert.com english...

  • Page 15: Overview Of Mounting Options

    Type 8791, REV.2 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 english...

  • Page 16: Structure

    Type 8791, REV.2 Structure 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 different device statuses to be displayed.

  • Page 17: Function

    Type 8791, REV.2 Function FUNCTION Functional diagram Exemplary presentation with single-acting actuator Compressed air Valve (proportional valve) with supply Positioner Type 8791 single-acting actuator Position set-point value Positioner Pilot valve Exhaust air system* Position sensor Actual position * Pilot valve system 1: Aeration valve 2: Exhaust valve 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.

  • Page 18: Position Control Function

    Type 8791, REV.2 Function 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) specified as the standard signal. If there is a control difference (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 difference 0. Z1 is a disturbance. Valve opening Position Positioner Pilot valve Valve set-point system value...

  • Page 19: Schematic Presentation Of The Position Control

    Type 8791, REV.2 Function 7.2.1 Schematic presentation of the position control 1) Can only be activated with com- munication software Fig. 4: Schematic presentation of the position control english...

  • Page 20: Functions Of The Positioner Software

    Type 8791, REV.2 Function 7.2.2 Functions of the positioner software Basic functions • Activation with DIP switch • Parameter setting with communication software Function Effect Sealing function Valve seals outside of the control range. Specifi- cation of the value (in %) from which the actuator is CUTOFF completely vented (at 0%) or aerated (at 100%) (see Chapter “9.3.2 DIP switch function”).
  • Page 21 Type 8791, REV.2 Function Auxiliary functions • Activation and parameter setting with communication software Function Effect Actuator inversion of direction Assignment of aeration status of the actuator chamber to the actual position. DIR.ACT Signal split range Standard signal in %, for which the valve runs through the whole stroke range.

  • Page 22: Positioner Interfaces

    Type 8791, REV.2 Function Positioner interfaces Input for Analogue position set-point position feedback value (Variant) Positioner 4...20 mA 0...20 mA 3 or 4 conductor Proximity switch 1, Digital input proximity switch 2 24 V PNP NO (optional) 24 V DC Communication Operation interface 4) Or via fieldbus communication (for example, büS/CANopen or IO-Link) 5) Factory setting is 4...20 mA, 4 conductor Fig.

  • Page 23: Technical Data

    Type 8791, REV.2 Technical data TECHNICAL DATA Standards and directives The device complies with the relevant EU harmonisation legislation. In addition, the device also complies with the requirements of the laws of the United Kingdom. The harmonised standards that have been applied for the conformity assessment procedure are listed in the current version of the EU Declaration of Conformity/UK Declaration of Conformity.

  • Page 24: Type Label

    Type 8791, REV.2 Technical data Type label Type Operating voltage Nominal power Device variants, communication, version 8791 24 V DC 5 W Operating pressure, degree of protection Remote IO-Link REV.2 Ambient temperature P=1.4...7 bar IP65/67 Tamb –10...+60°C CSA approval mark (for Canada and USA) ® CE marking Serial number S/N 1000 00123456...

  • Page 25: Electrical Data, Io-Link

    Type 8791, REV.2 Technical data 8.5.2 Electrical data, IO-Link Protection class III according to DIN EN 61140 (VDE 0140-1) Connection Circular plug-in connector M12 x 1, 5-pin, A-coded Port Class A Operating voltage 24 V DC ±25% (according to specification) Current consumption max. 150 mA Port Class B Operating voltage System supply (Pin 1+3) 24 V DC ±25% (according to specification) Actuator supply (Pin 2+5) 24 V DC ±25% (according to specification) Current consumption System supply (Pin 1+3)

  • Page 26: Pneumatic Data

    Type 8791, REV.2 Technical data Pneumatic data Control medium Neutral gases, air quality classes acc. to ISO 8573-1 Dust content Class 7, max. particle size 40 μm, Max. particle density 10 mg/m³ Water content C lass 3, max. pressure dew point –20 °C or min. 10 °C below the lowest operating temperature Oil content Class X, max. 25 mg/m³ Temperature range 0...+60 °C Pressure range 1.4…7 bar Air flow rate Universal air flow rate 50 l /min (at 1.4 bar ) for aeration and venting Single- and double-acting...

  • Page 27: Safety End Positions After Failure Of The Electrical Or Pneumatic Auxiliary Power

    Type 8791, REV.2 Technical data Safety end positions after failure of the electrical or pneumatic auxiliary power The safety end position depends on the pneumatic connection of the actuator to the working ports A1 or A2. Safety end positions after failure of the Actuator type Designation pneumatic auxi- electrical auxiliary power liary power univ. air flow...

  • Page 28: Positioner Factory Settings

    Type 8791, REV.2 Technical data Positioner factory settings 8.8.1 Functions that can be activated via DIP switch Function Parameters Value CUTOFF Sealing function bottom Sealing function top CHARACT Characteristic correction FREE DIR.CMD Inversion of direction set-point value Table 6: Factory settings; 8.8.2 Functions that can be activated via the communication software...

  • Page 29: Operation

    Type 8791, REV.2 Operation OPERATION Safety instructions WARNING! Risk of injury due to improper operation. Improper operation may result in injuries as well as damage to the device and its surroundings. ▶ The operating personnel must know and have understood the contents of the operating instructions. ▶...

  • Page 30: Assignment Of The Keys

    Type 8791, REV.2 Operation → To operate the keys and DIP switch, unscrew the four screws on the housing cover and remove the housing cover. 9.3.1 Assignment of the keys To be able to operate the DIP switch and keys, ensure that the on-site operating lock is not disabled/blocked (factory setting): with communication software or fieldbus communication. The assignment of the two keys inside the actuator housing varies depending on the operating state (AUTOMATIC/MANUAL).

  • Page 31: Dip Switch Function

    Type 8791, REV.2 Operation 9.3.2 DIP switch function To be able to operate the DIP switch and keys, ensure that the on-site operating lock is not disabled/blocked (factory setting): with communication software or fieldbus communication. 1 2 3 4 → To operate the keys and DIP switch, unscrew the four screws on the housing cover and remove the housing cover. DIP switch Position Function Reversal of the effective direction of the set-point value (DIR. CMD) (set-point value 20...4 mA = position 0...100%) Normal effective direction of the set-point value (set-point value 4...20 mA = position 0...100%)

  • Page 32: Led Display

    Type 8791, REV.2 Operation 9.3.3 LED display LED 1 LED 2 Fig. 12: LED display LED 1 Display of device status and valve position (RGB) LED 2 Bus status display (green) Feedback when pressing the keys to start functions • X.TUNE •...
  • Page 33 Type 8791, REV.2 Operation 9.3.4.1 Valve mode Displays in valve mode: • Valve position: open, in between, closed • Device status: failure Valve position Valve position Device status: failure State, colour State, colour open is lit yellow flashes red alternately with yellow in between is lit white flashes red alternately with white 15)16) 15)16) closed is lit green flashes red alternately with green Table 11:...

  • Page 34: Status Led, Green

    Type 8791, REV.2 Operation 9.3.4.3 NAMUR operation mode LED1 shows the device status. The display elements change colour in line with NAMUR NE 107. If several device statuses exist simultaneously, the device status with the highest priority is displayed. The priority is based on the severity of the deviation from controlled operation (red LED = failure = highest priority).

  • Page 35: Error Notifications

    Type 8791, REV.2 Operation Error notifications 9.4.1 Notifications on device status: Out of specification Message Description Measure Temperature warning Ambient temperature is too Reduce ambient temperature Contact limit exceeded high Bürkert Service if problem persists Temperature warning Ambient temperature is too low Increase ambient temperature limit undershot Voltage is above the Supply voltage is too high...
  • Page 36 Type 8791, REV.2 Operation IO-Link errors No valid process data was - Check connection to the IO-Link master received - Check whether valid set-point values can be sent via the IO-Link interface to the device X.TUNE error occurred The last X.TUNE was not -Check compressed air supply successful -Execute X.TUNE again Actuator supply failed...

  • Page 37: Functions

    Type 8791, REV.2 Functions FUNCTIONS The positioner Type 8791 has different basic and auxiliary functions that can be configured and paramete- rised via the DIP switch or communication software. 10.1 Basic functions The following basic functions can be activated (CUTOFF and CHARACT) or changed (DIR.CMD) via the DIP switch. The parameters for the sealing function (CUTOFF) and characteristic correction (CHARACT) are set with the communication software.

  • Page 38: Dir.cmd

    Type 8791, REV.2 Functions 10.1.1 DIR.CMD - Inversion of direction of the positioner set-point value This function sets the effective direction between the input signal (INPUT) and the position set-point value of the actuator. Factory setting: DIP switch OFF (rising) DIP switch Position Function Reversal of the effective direction of the set-point value (DIR. CMD) (20...4 mA corresponds to 0...100 %), dropping Normal effective direction of the set-point value (set-point value 4...20 mA corresponds to position 0...100%), increasing Table 20: DIP switch 1 The effective direction (DIR.CMD) can only be changed with DIP switch 1 in the positioner. Target position rising falling...

  • Page 39: Cutoff

    Type 8791, REV.2 Functions 10.1.2 CUTOFF - Sealing function for the positioner This function ensures that the valve is tightly closed outside the control range. Closed-loop control mode resumes with hysteresis of 1%. Factory setting: D IP switch 2 to OFF (no sealing function) DIP switch Position Function Sealing function active.

  • Page 40: Charact

    Type 8791, REV.2 Functions 10.1.3 CHARACT - Characteristic correction between the input signal (position set-point value) and stroke Characteristic (client-specific characteristic) This function enables a transfer characteristic with regard to the set-point value (position set-point value) and valve stroke for correcting the flow or operating characteristic. The transfer characteristic can only be changed with communication software. Factory setting: DIP switch 3 OFF (linear) DIP switch Position Function Correction characteristic for adjusting the operating characte- ristic (linearization of the operating characteristic, CHARACT)
  • Page 41 Type 8791, REV.2 Functions The flow characteristic k = f(s) indicates the flow rate of a valve, expressed by the k value, as a function of the stroke s of the actuator spindle. It is determined by the shape of the valve seat and the seat seal. Two types of flow characteristics are generally realised: the linear and the equal percentile. With linear characteristics, equal stroke changes are apportioned the same k value changes dk ⋅...

  • Page 42: Input

    Type 8791, REV.2 Functions Input of the freely programmable characteristic The characteristic is defined via 21 supporting points which are evenly distributed over the set-point range from 0 to 100%. Their spacing is 5%. A freely selectable stroke (setting range 0...100%) can be assigned to each supporting point. The difference between the stroke values of two adjacent supporting points must not be greater than 20%. Example of a programmed characteristic Valve stroke [&] Standard signal 90 100 4...20 mA 0...20 mA Fig.

  • Page 43: Reset/Factory Reset - Reset Device To Factory Settings

    Type 8791, REV.2 Functions 10.1.5 RESET/FACTORY RESET - Reset device to factory settings This function resets the positioner to the factory settings. 10.1.6 X.TUNE - Automatic calibration of the positioner to the respective operating conditions For a functional inspection of the positioner, the X.TUNE function must be executed to adapt the positioner to the local conditions. WARNING! During execution of the X.TUNE function, the valve automatically moves from its current position. ▶ Never execute X.TUNE when a process is running. ▶...

  • Page 44: Auxiliary Functions

    Type 8791, REV.2 Functions 10.2 Auxiliary functions The following auxiliary functions can be configured and parameterised with the communication software: Function Description Actuator inversion of direction Assignment of aeration status of the actuator chamber to the actual position DIR.ACT Signal split range Signal split range: input signal in % for which the valve runs through the whole stroke range. SPLTRNG Stroke limitation Limitation of mechanical stroke range X.LIMIT Actuating time limit Limit of control speed...

  • Page 45: Dir.act

    Type 8791, REV.2 Functions 10.2.1 DIR.ACT - Actuator inversion of direction This function sets the effective direction between the pressurisation state of the actuator and the actual position. Factory setting: off (rising) Rising: Direct effective direction (vented → 0%; aerated 100%) dropping: Inverse effective direction (vented → 100%; aerated 0%) Actual position rising falling State of pressurisation vented aerated Fig. 17: Diagram DIR.ACT english...

  • Page 46: Spltrng

    Type 8791, REV.2 Functions 10.2.2 SPLTRNG - Signal split range Minimum and maximum value of the input signal in % for which the valve runs through the whole stroke range. Factory setting: signal split range bottom = 0%; signal split range top = 100% Signal split range bottom: I nput of the minimum value of input signal in %: Setting range: 0...75% Signal split range top: I nput of the maximum value of the input signal in % Setting range: 25...100% This function limits the position set-point value range of the positioner by setting a minimum and maximum value. This makes it possible to split a used standard signal range (4...20 mA, 0...20 mA) into several positioners (without or with overlap).

  • Page 47: X.limit

    Type 8791, REV.2 Functions 10.2.3 X.LIMIT - Stroke limitation This function limits the (physical) stroke to predetermined % values (bottom and top). The stroke range of the limited stroke is thereby set to 100%. If the limited stroke range is exceeded during operation, negative actual positions or actual positions greater than 100% are displayed.

  • Page 48: X.time

    Type 8791, REV.2 Functions 10.2.4 X.TIME - Actuating time limit This function can be used to set the opening and closing times for the entire stroke, and thus limit the control speeds. When performing the X.TUNE function, the minimum opening and closing time are entered for the entire stroke for Open and Close. This facilitates movement at maximum speed. Factory setting: factory-set values through the X.TUNE function If the control speed is to be reduced, values can be entered for Open and Close which lie between the minimal values to be determined by X.TUNE and 60 s.

  • Page 49: X.control

    Type 8791, REV.2 Functions 10.2.5 X.CONTROL - control parameter of the positioner This function sets the parameters of the positioner (dead band and amplification factors). Dead band: Insensitivity range of the positioner Input of the dead band in %, based on the scaled stroke range; i.e. X.LIMIT Stroke limitation top - X.LIMIT Stroke limitation bottom (See auxiliary function X.LIMIT). This function ensures that the controller does not respond until a certain control difference is reached. This function protects the solenoid valve in the positioner and the pneumatic actuator.

  • Page 50: Sig.error

    Type 8791, REV.2 Functions 10.2.7 SIG.ERROR - Configuring the cable break detection (only for variants without fieldbus communication) The cable break detection function (SIG.ERROR) is used to detect an error on the set-point value signal. Cable break detection can only be selected with 4...20 mA signal: error with set-point value at ≤ 3.5 mA (±0.5% of end value, hysteresis 0.5% of end value) When selecting 0...20 mA, the cable break detection cannot be selected. If cable break detection is enabled (error or outside of the specification), a signal error is displayed via LED 1 on the device. Safety position when the cable break detection is enabled: Active safety position (SAFEPOS) function When an error is detected, the actuator moves to the position set under safety position.

  • Page 51: Output (Variant)

    Type 8791, REV.2 Functions 10.2.9 OUTPUT (variant) - Configuring the analogue output (only for variants without fieldbus communication) The analogue output (OUTPUT) function only appears in the function selection if the positioner has an ana- logue output (variant) or no parameters have been read in yet. The analogue output can be used for feedback from the current position or from the set-point value at the control centre.

  • Page 52: Mounting And Installation

    Type 8791, REV.2 Mounting and installation MOUNTING AND INSTALLATION You can find the dimensions of the positioner and the different device variants in the data sheet. 11.1 Safety instructions WARNING! Risk of injury due to improper installation. ▶ Installation may be carried out by authorised technicians only and with the appropriate tools. Risk of injury due to unintentional activation of the system and uncontrolled restart. ▶ Secure system against unintentional activation. ▶ Ensure a controlled restart after installation. english...

  • Page 53: Mounting On A Continuous Valve With Linear Actuator According To Namur

    Type 8791, REV.2 Mounting and installation 11.2 Mounting on a continuous valve with linear actuator according to NAMUR The valve position is transmitted to the position sensor installed in the positioner via a lever (in accordance with NAMUR). 11.2.1 Attachment kit (in accordance with IEC 534-6) on linear actuators (order number 787215) (Can be obtained from Bürkert as an accessory.)

  • Page 54: Installation

    Type 8791, REV.2 Mounting and installation 11.2.2 Installation WARNING! Risk of injury due to improper installation. ▶ Installation may be carried out by authorised technicians only and with the appropriate tools. Risk of injury due to unintentional activation of the system and uncontrolled restart. ▶ Secure system against unintentional activation. ▶ Ensure a controlled restart after installation. Procedure: ②...
  • Page 55 Type 8791, REV.2 Mounting and installation 16 16 12 12 18 18 19 19 14 14 12 12 22 22 13 13 15 15 Fig. 23: Lever installation The gap between the driver pin and the shaft should be the same as the actuator stroke. As a result, the lever has an ideal rotational range of 60° (see “Fig. 24”). Position sensor angular range: The maximum angular range of the position sensor is 180°. Rotational range of the lever: To ensure that the position sensor works with good resolution, the rotational range must be between 30° and 120°. The scale printed on the lever is not relevant. 120° Maximum rota- tional range of the lever Rotational range of the lever Ideal: 60°...

  • Page 56: Attaching The Mounting Bracket

    Type 8791, REV.2 Mounting and installation 11.2.3 Attaching the mounting bracket ① ⑨ → Attach the mounting bracket to the rear of the positioner using the hexagon bolts , the spring lock ⑩ ⑪ washers and the washers (see “Fig. 25”). Selection of the M8 thread used on the positioner depends on the actuator size.

  • Page 57: Aligning The Lever Mechanism

    Type 8791, REV.2 Mounting and installation Attaching the positioner with the mounting bracket for actuators with a columnar yoke: ⑦ ⑪ → Attach the mounting bracket to the columnar yoke using the U-bolt , the washers , the spring lock ⑩ washers and the hexagon nuts (see “Fig. 27”). Fig. 27: Attaching the positioner with the mounting bracket; for actuators with a columnar yoke 11.2.4 Aligning the lever mechanism The lever mechanism cannot be correctly aligned until the device has been electrically and pneu-...

  • Page 58: Mounting On A Continuous Valve With Rotary Actuator

    Type 8791, REV.2 Mounting and installation 11.3 Mounting on a continuous valve with rotary actuator The shaft of the position sensor integrated into the positioner is directly connected to the shaft of the rotary actuator. 11.3.1 Attachment kit (in accordance with VDI/VDE 3845) on rotary actuator (Order number 787338) (Can be obtained from Bürkert as an accessory.) Pieces...
  • Page 59 Type 8791, REV.2 Mounting and installation Anti-twist safeguard: Observe the spot face on the shaft. One setscrew must lie on the spot face of the shaft as an anti-twist safeguard (see “Fig. 28”). Angular range of the position sensor: The maximum angular range of the position sensor is 180°. The shaft of the positioner should only be used within this range. ① → Insert adapter on to the shaft of the positioner and attach with two setscrews. → Secure the setscrew with self-locking nuts. 180° Maximum rota- tional range The rotational movement of the levelled shaft must be within the position sensor angular...
  • Page 60 Type 8791, REV.2 Mounting and installation ① ④ ③ Fig. 29: Attaching assembly bridge (schematic representation) → Place the positioner with the assembly bridge on the rotary actuator and attach it using four hexagon bolts (see “Fig. 30”). Fig. 30: Rotary actuator attachment english...

  • Page 61: Remote Operation With External Position Sensor

    Type 8791, REV.2 Mounting and installation 11.4 Remote operation with external position sensor In this variant, the positioner does not have a position sensor in the form of an angle of rotation sensor but has an external remote sensor. The Type 8798 remote sensor is connected using a serial digital interface. 11.4.1 Attachment accessories There are two options for attaching the positioner in remote operation (see “Fig.

  • Page 62: Connection And Start-Up Of The Remote Sensor Type 8798

    Type 8791, REV.2 Mounting and installation 11.4.2 Connection and start-up of the remote sensor Type 8798 WARNING! Risk of injury due to improper start-up. ▶ Start-up may be carried out by authorised technicians only and with the appropriate tools. Risk of injury due to unintentional activation of the system and uncontrolled restart. ▶ Secure system against unintentional activation. ▶...

  • Page 63: Pneumatic Connection

    Type 8791, REV.2 Pneumatic connection PNEUMATIC CONNECTION 12.1 Safety instructions DANGER! Risk of injury from high pressure in the system/device. ▶ Before working on the system or device, switch off the pressure and vent/empty the lines. WARNING! Risk of injury due to improper installation. ▶ Installation may be carried out by authorised technicians only and with the appropriate tools. Risk of injury due to unintentional activation of the system and uncontrolled restart. ▶ Secure system against unintentional activation. ▶ Following installation, ensure a controlled restart. Working port 2 (Connection: A2) Pressure port 1.4...7 bar...
  • Page 64 Type 8791, REV.2 Pneumatic connection Procedure: → Apply supply pressure (1.4...7 bar) to the pressure port P. For single-acting actuators (control function A and B): → Connect working port (A1 or A2, depending on the desired safety end position) to the chamber of the single-acting actuator. For safety end positions see Chapter “8.7 Safety end positions after failure of the electrical or pneumatic auxiliary power”.

  • Page 65: Electrical Installation Without Fieldbus Communication

    Type 8791, REV.2 El e ctri c al i n stal l a ti o n wi t hout fi e l d bus communi c ati o n ELECTRICAL INSTALLATION WITHOUT FIELDBUS COMMUNICATION All electrical inputs and outputs of the device are not galvanically isolated to the supply voltage. 13.1 Safety instructions DANGER!

  • Page 66: Pin Assignment For Input Signals From Control Centre (E.g. Plc)

    Type 8791, REV.2 El e ctri c al i n stal l a ti o n wi t hout fi e l d bus communi c ati o n 13.2.2 Pin assignment for input signals from control centre (e.g. PLC) Pin Wire Assignment Device end...

  • Page 67: Pin Assignment For Operating Voltage

    Type 8791, REV.2 El e ctri c al i n stal l a ti o n wi t hout fi e l d bus communi c ati o n 13.2.4 Pin assignment for operating voltage Wire colour* Assignment External circuit/signal level green 24 V DC ±25% max.

  • Page 68: Terminal Assignment For Input Signals From Control Centre (E.g. Plc)

    Type 8791, REV.2 El e ctri c al i n stal l a ti o n wi t hout fi e l d bus communi c ati o n 13.3.3 Terminal assignment for input signals from control centre (e.g. PLC) Terminal Assignment Device end...

  • Page 69: Terminal Layout For Operating Voltage

    Type 8791, REV.2 El e ctri c al i n stal l a ti o n wi t hout fi e l d bus communi c ati o n 13.3.5 Terminal layout for operating voltage Terminal Assignment External circuit/signal level +24 V Operating voltage + +24 V 24 V DC ±25% max.

  • Page 70: Electrical Installation, Io-Link

    Type 8791, REV.2 Electrical installation, IO-Link ELECTRICAL INSTALLATION, IO-LINK M8 socket, 4-pin M12 plug x 1, 5-pin (remote variant only) Fig. 35: Pin assignment Pin assignment port class A Designation Assignment 24 V DC System supply Not used L – 0 V (GND) System supply IO-Link Communication Not used Table 37: Pin assignment port class A Pin assignment port class B...
  • Page 71 Type 8791, REV.2 Electrical installation, IO-Link Positioner Wire colour Wire colour Remote sensor with cable type 1 Remote sensor with cable type 2 brown brown white black green yellow orange Table 40: Assignment of wire colour on the remote sensor english...

  • Page 72: Electrical Installation, Büs

    Type 8791, REV.2 Electrical installation, büS ELECTRICAL INSTALLATION, BÜS Wire colour Assignment CAN label/shielding CAN label/shielding 24 V DC ±25% max. residual ripple 10% black GND/CAN_GND white CAN_H blue CAN_L Table 41: Pin assignment For electrical installation with büS network note the following: Use a 5-pin circular plug and a shielded 5-wire cable. The shielding is capacitively connected to the functional earth through the device. 15.1 Connection assignment for external position sensor (only for remote variant)

  • Page 73: Start-Up

    Type 8791, REV.2 Start-up START-UP 16.1 Safety instructions WARNING! Risk of injury due to improper operation. Improper operation may result in injuries as well as damage to the device and the area around it. ▶ Before start-up, ensure that the operating personnel are aware of and have completely understood the contents of the operating instructions.

  • Page 74: Set Device With Bürkert Communicator

    Type 8791, REV.2 Start-up → Start X.TUNE by pressing key 1 for 5 s LED 2 flashes at 5 Hz. The device is in NAMUR state functional inspection, LED1 lights orange. If X.TUNE has been successfully complete, the NAMUR state is reset. The changes are automatically adopted in the memory (EEPROM). If LED1 lights red after X.TUNE: → Execute X.TUNE again. → Perform device restart if necessary. 16.3 Set device with Bürkert Communicator All settings can be made on the device with Bürkert Communicator. You can find the settings in Bürkert Communicator in the operating instructions.

  • Page 75: Connecting The Büs Device To The Bürkert Communicator

    Type 8791, REV.2 Start-up → Insert the Micro USB plug into the communication interface. → Make the connection to the PC with the USB büS interface set. → Start the Bürkert Communicator. → Configure settings. 16.3.2 Connecting the büS device to the Bürkert Communicator Necessary components: •...

  • Page 76: Io-Link

    0x0078, 120 DeviceID See IODD file ProductID 8791 Transmission speed COM3 (230.4 kbit/s) PD input bits PD output bits M-sequence cap. 0x0D Min. cycle time 5 ms Data storage Max. line length 20 m 17.3 Configuring the fieldbus The necessary start-up files and the description of the process data and acyclic parameters are available online. Download at: www.burkert.com / Type 8791 / Software english...

  • Page 77: 18 Büs

    Type 8791, REV.2 büS BÜS 18.1 Information, büS büS is a system bus developed by Bürkert with a communication protocol based on CANopen. 18.2 Configuring the fieldbus The necessary start-up files and the description of the objects are available online. Download at: www.burkert.com / Type 8791 / Software english...

  • Page 78: Maintenance

    772406 büS cable extension (M12 plug to M12 socket), length 10 m 772407 Table 44: Accessories 20.1 Communication software The Communicator PC operating program has been designed for communication with devices from the Bürkert positioner family. Please contact the Bürkert Sales Center for compatibility questions. A detailed description of the installation and operation of the software can be found in the asso- ciated operating instructions. Download the software from: country.burkert.com. english...

  • Page 79: Packaging, Transport, Disposal

    ▶ Store the device in a dry and dust-free location. ▶ Storage temperature: –20...+65 °C Environmentally friendly disposal ▶ Follow national regulations regarding disposal and the environment. ▶ Collect electrical and electronic devices separately and dispose of them as special waste. Further information country.burkert.com. english...
  • Page 80 Type 8791, REV.2 english...
  • Page 81 www.burkert.com...

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