The Positoner Type 8791 REV.2 is designed to be mounted on pneumatic actuators of process valves for the control of media. The permitted fluid media are listed in the technical data.

▶ Use the device for its intended purpose only. Non-intended use of the device may be dangerous to people, nearby equipment and the environment.

▶ Correct transportation, correct storage as well as correct installation, commissioning, operation and maintenance are essential for reliable and problem-free operation.

▶ When using the device, observe the permitted data, operating conditions and application conditions. This information can be found in the contractual documents, the operating instructions and on the type label.

▶ Use the device only in conjunction with third-party devices and components recommended and authorized by Bürkert.

▶ Do not use the device outdoors without protection from the weather.

▶ In areas at risk of explosion, only use devices approved for use in those areas. These devices are labeled with a separate

Ex type label. For such use, note the information provided on the separate Ex type label and the additional explosionrelated information or separate explosion-related operating instructions.

▶ Pulsating direct voltage (rectified alternating voltage without smoothing) must not be used as power supply.

Type 8791 REV.2

Intended use

3 BASIC SAFETY INSTRUCTIONS

These safety instructions do not consider any contingencies or incidents which occur during installation, operation and maintenance.

The operator is responsible for observing the location-specific safety regulations, also with reference to the personnel.

DANGER

Risk of injury from high pressure and discharge of medium.

▶ Before working on the device or system, switch off the pressure. Vent or drain lines.

Risk of injury from electric shock.

▶ Before working on the device or system, switch off the power supply. Secure against reactivation.

▶ Observe applicable accident prevention and safety regulations for electrical equipment.

To prevent injury, ensure the following:

▶ Secure device or system to prevent unintentional activation.

▶ Only trained technicians may perform installation and maintenance work.

▶ Perform installation and maintenance with suitable tools only.

▶ Do not make any changes to the device and do not subject it to mechanical stress.

▶ Operate the device only in perfect state and in consideration of the operating instructions.

▶ Observe the general rules of technology.

▶ Install the device according to the regulations applicable in the respective country.

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Type 8791 REV.2

General information

▶ Do not feed corrosive or flammable media into the device connections.

▶ Do not feed any fluids into the connections of the device.

▶ After the process is interrupted, restart in a controlled manner. Observe sequence:

1. Connect electrical or pneumatic power supply.

2. Charge the device with medium.

▶ Observe intended use.

NOTE!

Electrostatic sensitive components or 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 damage caused by sudden electrostatic discharge.

▶ Also ensure that you do not touch electronic components when the power supply voltage is present.

4 GENERAL INFORMATION

4.1

Contact addresses

Germany

Bürkert Fluid Control Systems

Sales Center

Christian-Bürkert-Str. 13-17

D-74653 Ingelfingen

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 final 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 8694 is used as intended in accordance with the specified application conditions.

4.3

Information on the internet

The operating instructions and data sheets for Type 8694 can be found on the Internet at: www.burkert.com

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5 DESCRIPTION OF SYSTEM

5.1

Structure

Mechanical position indicator

Display module with 2 LEDs

Fig. 1: Structure, positioner Type 8791

Working connection 2

(connection: A2)

Supply pressure connection 1.4 – 7 bar

(connection: P)

Working connection 1

(connection: A1)

Air exhaust connection/ air exhaust filter

Pressure-relief valve

Type 8791 REV.2

Description of system

Electronic module

Internal position sensor

Pilot valve system

Axle for position sensor

Cable gland

Fig. 2: Structure, positioner Type 8791

5.2

General description

The positioner Type 8791 is a digital, electro-pneumatic position controller for pneumatically actuated continuous valves. The device incorporates the main function groups

- Position sensor

- Electro-pneumatic pilot valve 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 set-point position value specified via the standard signal input and supplies the result to the position controller. If there is a control difference, the electro-pneumatic valve pilot system corrects the actual position accordingly.

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Type 8791 REV.2

Technical data

6 TECHNICAL DATA

6.1

Conformity

In accordance with the EU Declaration of conformity, the positioner Type 8791 is compliant with the EU Directives.

6.2

Standards

The applied standards, which verify conformity with the EU

Directives, can be found on the EU-Type Examination Certificate and / or the EU Declaration of Conformity.

6.3

Operating conditions

WARNING!

Solar radiation and temperature fluctuations may cause mal functions or leaks.

▶ If the device is used outdoors, do not expose it unprotected to the weather conditions.

▶ Ensure that the permitted ambient temperature does not exceed the maximum value or drop below the minimum value.

Ambient temperature see type label

Degree of protection IP65 / IP67 1) according to EN 60529

(only if cables, plugs and sockets have been connected correctly)

Operating altitude up to 2000 m above sea level

1) If the positioner is used under IP67 conditions, the ventilation filter

(see “Fig. 1”) must be removed and the exhaust air conducted into the

dry area.

6.4

Mechanical data

Dimensions See data sheet

Material

Housing material Plastic-coated aluminium

Other external parts Stainless steel (V4A), PC, PE, POM,

PTFE

Sealing material EPDM, NBR, FKM

Weight approx. 1.0 kg

6.5

Type label

Type Operating voltage

8791 24V DC 5W

Remote IO-Link REV.2

P=1.4...7bar IP65/67

Tamb –10...+60°C

C US

S/N 1000

00123456 W17MA

Nominal power

Device variant, communication, version

Operating pressure, degree of protection

Ambient temperature

Approval marking CSA

(for Canada and USA)

CE marking

Serial number

Order number, manufacture code

Barcode

Fig. 3: Type label (example) english 9

6.6

Electrical data

6.6.1

Electrical data, without field bus communication

Protection class III in accordance with DIN EN 61140

(VDE 0140-1)

Connections 2 cable glands (M20 x 1.5) with screwtype terminals 0.14 – 1.5 mm 2 or circular plug-in connector (M12, 8-pin plug)

Operating voltage 24 V DC ±25 %, max. residual ripple 10%

Current consumption max. 190 mA

Power consumption max. 3.5 W

Input resistance for set-point value signal 75 Ω in 0/4 – 20 mA / 12 bit resolution

Analog position feedback max. Burden (load) for current output

0/4 – 20 mA) 560 Ω

Inductive proximity switches 100 mA current limit

Digital input 0–5 V = logical “0”, 10–30 V = logical “1” logic invertible in software

(input current < 6 mA)

Communications Connection to PC via USB bus interface interface set

Communication software Bürkert Communicator

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Type 8791 REV.2

Technical data

6.6.2

Electrical data, IO-Link

Protection class III as per DIN EN 61140 (VDE 0140-1)

Connection Circular plug-in connector M12 x

1, 5-pin, A-coded, Port Class B

Operating voltage

System supply (Pin 1+3) 24 V DC ±25 %

(according to specification)

Actuator supply (Pin 2+5) 2) 24 V DC ±25 %

(according to specification)

Current consumption

System supply (Pin 1+3) max. 50 mA

Actuator supply (Pin 2+5) max. 100 mA

Total power consumption max. 3.5 W

2) Actuator supply is galvanically isolated from system supply in accordance with IEC 60664 and for electrical safety in accordance with

SELV from IEC 61010-2-201

6.6.3

Electrical data, büS

Protection class III as per DIN EN 61140

(VDE 0140-1)

Connection Circular plug-in connector M12 x 1,

5-pin, A-coded

Operating voltage 24 V DC ±25 %

(according to specification)

Current consumption max. 150 mA

Total power consumption max. 3.5 W

Type 8791 REV.2

Operating

6.7

Pneumatic data

Control medium Neutral gases, air

Quality classes in accordance with ISO

8573-1

Dust content Class 7, max. particle size 40 µm, max. particle density 10 mg/m³

Water content Class 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 50 l

/min (at 1.4 bar deaeration

) for aeration and

150 l

/min (at 6 bar

) for aeration and deaeration

= 100 l

/min (according to definition for pressure drop from 7 to 6 bar absolute).

Connections Internal thread G1/4“

7 OPERATING

7.1

Operating state

AUTOMATIC (AUTO)

Normal controller mode is implemented and monitored in AUTO-

MATIC operating state.

MANUAL

In MANUAL operating state the valve can be opened and closed manually via the buttons.

To operate the DIP switches and buttons, make sure that the local control lock is deactivated/unlocked (factory setting): with communication software or fieldbus communication.

DIP switch 4 can be used to switch between the two operating

states AUTOMATIC and MANUAL (see chapter “7.2.2 Function of the DIP switches”).

3) Pressure specifications: Overpressure with respect to atmospheric pressure english 11

7.2

Control and display elements of the positioner

To operate the DIP switches and buttons, make sure that the local control lock is deactivated/unlocked (factory setting): with communication software or fieldbus communication.

Button 1

DIP Switches

LED 1

LED 2

Type 8791 REV.2

Operating

7.2.1

Configuration of the buttons

To operate the DIP switches and buttons, make sure that the local control lock is deactivated/unlocked (factory setting): with communication software or fieldbus communication.

The configuration of the 2 buttons inside the housing varies depending on the operating state (AUTOMATIC / MANUAL).

The description of the operating state (AUTOMATIC / MANUAL) can

be found in the chapter entitled “7.1 Operating state” .

Button 1

Button 2

Communications interface

Fig. 4: Description of control elements

The positioner features 2 buttons, 4 DIP switches and 2 LEDs as a display element.

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Fig. 5: Description of the buttons

→ To operate the buttons and DIP switches, unscrew the 4 screws on the housing cover and remove the housing cover.

Type 8791 REV.2

Operating

MANUAL operating state (DIP switch 4 set to ON):

Button Function

1 Aerate (manually open / close the actuator) 4)

2 Deaerate (manually open / close the actuator) 4)

1 and 2 simultaneously

Longer than 10 s (< 30 s, LED 2 flashes at 5 Hz):

Device restart

Longer than 30 s (LED 2 flashes at 10 Hz):

Reset device to factory setting

Tab. 1: Configuration of the buttons for MANUAL operating state

AUTOMATIC operating state (DIP switch 4 set to OFF):

Button Function

1 Press for 5 s to start the X.TUNE

function

2 -

1 and 2 simultaneously

Longer than 10 s (< 30 s, LED 2 flashes at 5 Hz):

Device restart

Longer than 30 s (LED 2 flashes at 10 Hz):

Reset device to factory setting

Tab. 2: Configuration of the buttons for AUTOMATIC operating state

4) Depending on the operating principle of the actuator.

7.2.2

Function of the DIP switches

ON DIP

DIP switches

Function

1 2 3 4

1 ON Reversal of the effective direction of the set-point value (20 – 4 mA corresponds to 0 – 100 %), descending ( DIR.CMD

)

OFF Normal effective direction of the set-point value

(4 – 20 mA corresponds to 0 – 100 %), ascending

2 ON Sealing function active. The valve completely closes below 2 % 5) and opens above 98 % of the set-point value ( CUTOFF )

OFF No sealing function

3 ON Correction characteristic for adjustment of the operating characteristic ( CHARACT ) 5)

OFF Linear characteristic

4 ON Operating status MANUAL (MANU)

OFF Operating status AUTOMATIC (AUTO)

Tab. 3: DIP switches

5) Can be changed via communications software.

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Information about the communications software:

The switching position of the DIP switch has priority over the communications software.

If the values of the sealing function ( CUTOFF ) or the correction characteristic ( CHARACT ) are changed via the communications software, the corresponding function must be active (DIP switch set to ON).

The effective direction of the set-point value ( DIR.CMD

) can be changed via the DIP switches.

7.2.3

Display of the LEDs

LED 1

LED 2

Type 8791 REV.2

Operating

7.2.4

Device status display

The LED 1 (RGB) show the device status.

The user can set the following LED modes for the display of device status and valve position.

• Valve mode

• Valve mode with error messages

• Valve mode with error messages and warnings (factory setting)

• NAMUR mode

• LED off

The LED mode and the colors of the valve position can be set with the Bürkert Communicator.

IO-Link:

The LED mode and the colors of the valve position can be also set with an acyclic parameter (see parameter list).

The description for setting the LED mode can be found in the section "Setting the LED mode, device status" in the operating manual.

Fig. 6: LED display

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Type 8791 REV.2

Operating

7.2.5

Valve mode + warnings (factory setting)

Displays in valve mode + warnings:

• Valve position: open, half-way, closed

• Device status: failure, function check, out of specification, maintenance required (according to NAMUR)

Valve position

Open

Half-way

Status, color is lit yellow

6) is lit white 6)7)

Device status

Normal operation

Closed is lit green

6) --

Valve mode + warnings, normal operation

If several device statuses exist simultaneously, the device status with the highest priority is displayed.

Valve position

Open

Device status

Failure Function check

Status, color flashes red

Status, color flashes orange

Out of specification

Status, color flashes yellow

Maintenance required

Status, color blinks blue alternately with yellow 6)

Half-way flashes red flashes orange flashes yellow blinks blue alternately with white

6)7)

Closed flashes red flashes orange flashes yellow

Valve mode + warnings, device status flashes blue alternately with green 6)

For warning messages, the LEDs are briefly switched off between the change of the colors.

For localizations, the colors are only shown momentarily.

6) Factory setting, selectable colors for the valve position: Off, white, green, blue, yellow, orange, red

7) As of firmware A.1.6

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Type 8791 REV.2

Operating

7.2.6

NAMUR mode

The LED 1 show the device status.

The display elements change color in accordance with NAMUR

NE 107.

If several device statuses exist simultaneously, the device status with the highest priority is displayed. The priority is determined by the severity of the deviation from controlled operation (red

LED = failure = highest priority).

Status display in accordance with NE 107, edition 2006-06-12

Color Color code

Status Description

Red

Orange

Outage, error or malfunction

Function check

Normal operation is not possible due to a malfunction in the device or on its peripheral equipment.

Work is being carried out on the device; normal operation is therefore temporarily not possible

Yellow 3

Blue 2

Out of specification

Maintenance required

Ambient conditions or process conditions for the device are outside the specified area.

The device is in normal operation, although a function is briefly restricted.

→ Service device.

Status display in accordance with NE 107, edition 2006-06-12

Color Color code

Status Description

Green 1 Diagnostics active

Device is operating perfectly.

Status changes are indicated in different colors.

Messages are transmitted via a fieldbus if connected.

Tab. 4: Description of the colors

7.2.7

Status LED, green

LED 2 (green) indicates the following:

Color Status

Green is not lit flashes

Description

IO-Link communication inactive

IO-Link communication active

8) flashes with 5 Hz Feedback during pressing button 1

(start X.TUNE) or button 1+2 (device restart) > 5 s flashes with 10 Hz Feedback during pressing button

1+2 (reset to factory settings) > 30 s

Tab. 5: LED 2, green

8) Only IO-Link variant.

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Type 8791 REV.2

Attachment and assembly

8 ATTACHMENT AND ASSEMBLY

8.1

Installation of devices for the Ex area

When installing devices in the potentially explosive atmosphere, observe the “Additional information for use in the Ex area“ enclosed with the Ex-devices.

8.2

Attachment to a continuous valve with linear actuators according to NAMUR

The valve position is transferred to the position sensor installed in the positioner via a lever (according to NAMUR).

The attachment kit for the linear actuators can be purchased from Bürkert as an accessory by quoting the identification number 787215. The associated parts are

listed in the “Tab. 6: Attachment kit for linear actuators”

Part no. Quantity Name

NAMUR mounting bracket IEC 534

Hoop

Clamping piece

Driver pin

Conical roller

NAMUR lever for stroke range 3 – 35 mm

NAMUR lever for stroke range 35 – 130 mm

Tab. 6: Attachment kit for linear actuators

U-bolt

Hexagon bolt DIN 933 M8 x 20

Hexagon bolt DIN 933 M8 x 16

Circlip DIN 127 A8

Washer DIN 125 B8.4

Washer DIN 125 B6.4

Spring VD-115E 0.70 x 11.3 x 32.7 x 3.5

Spring washer DIN 137 A6

Locking washer DIN 6799 - 3.2

Circlip DIN 127 A6

Hexagon bolt DIN 933 M6 x 25

Hexagon nut DIN 934 M6

Square nut DIN 557 M6

Hexagon nut DIN 934 M8

Guide washer 6.2 x 9.9 x 15 x 3.5

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8.2.1

Installation

WARNING!

Risk of injury from improper installation.

▶ Installation may be carried out by authorised technicians only and with the appropriate tools.

Risk of injury from unintentional activation of the system and an uncontrolled restart.

▶ Secure system from unintentional activation.

▶ Following assembly, ensure a controlled restart.

Yoke mount procedure:

→ Using the bracket

⑰

and circlips

⑯

②

the clamping pieces

③

, hexagon bolts

attach the hoop to the actuator spindle.

Type 8791 REV.2

Attachment and assembly

→ Select short or long lever according to the stroke of the

actuator (see “Tab. 6: Attachment kit for linear actuators”,

part no. 6a/6b).

→

Assemble lever (if not pre-assembled) (see “Fig. 8”).

Fig. 7: Attaching the hoop

Fig. 8: Assembling the lever

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Type 8791 REV.2

Attachment and assembly

The gap between the driver pin and the axle should be the same as the drive stroke. This results in the ideal

angular range of the lever of 60° (see “Fig. 9”).

Angular range of the position sensor:

The maximum angular range of the position sensor is

150°.

Rotational range of the lever:

To ensure that the position sensor operates at a good resolution, the rotational range of the lever must be at least 30°.

The rotational movement of the lever must be within the position sensor angular range of 150°.

The scale printed on the lever is not relevant.

Rotational range of the lever

Ideal: 60°

Minimal: 30°

Maximum: 150°

The swivel movement of the lever must be within the position sensor slewing range of 150°.

Fig. 9: Rotational range of the lever

→ Attach lever to the axle of the positioner and screw tight ( and

⑲

⑰ english 19

Type 8791 REV.2

Attachment and assembly

8.2.2

Attaching mounting bracket

→ Attach mounting bracket hexagon bolts

⑨

, circlip

①

to the back of the positioner with

and washers

⑪

(see “Fig. 10”).

The selection of the M8 thread used on the positioner depends on the size of the actuator.

→ To determine the correct position, hold the positioner with mounting bracket on the actuator.

The conical roller on the lever of the position sensor in the hoop must be able to run freely on the drive over the entire stroke range.

At 50% stroke the lever position should be approximately

horizontal (see chapter “8.2.3 Aligning lever mechanism”).

M8 thread

Attaching the positioner with mounting bracket for actuators with cast frame:

→ Attach mounting bracket to the cast frame with one or more hexagon bolts

11”).

⑧

, washers

⑪

and circlips

⑩

(see “Fig.

⑨

8 10 11

①

⑩ ⑪

Fig. 10: Attaching mounting bracket

Fig. 11: Attach positioner with mounting bracket; for actuators with cast frame

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Type 8791 REV.2

Attachment and assembly

Attaching the positioner with mounting bracket for actuators with columnar yoke:

→

⑦

, washers

12”).

⑪

, circlips

⑩

and hexagon nuts 21

(see “Fig.

Fig. 12: Attach positioner with mounting bracket; for actuators with columnar yoke

8.2.3

Aligning lever mechanism

The lever mechanism cannot be correctly aligned until the device has been connected electrically and pneumatically.

→ Move the actuator in manual mode to half stroke (according to the scale on the actuator).

→ Adjust the height of the positioner until the lever is horizontal.

→ Fix the positioner in this position on the actuator.

8.3

Attachment to a continuous valve with rotary actuator

The axle of the position sensor integrated in the positioner is connected directly to the axle of the rotary actuator.

The assembly bridge can be purchased from Bürkert as an accessory by quoting the identification number

770294.

The attachment kit for the rotary actuators can be purchased from Bürkert as an accessory by quoting the identification number 787338.

The associated parts are listed in the “Tab. 7: Mounting kit on rotary actuator”

Part no. Quantity

Name

Adapter

Setscrew DIN 913 M4 x 10

Cheese-head screw DIN 933 M6 x 12

Circlip B6

Hexagon nut DIN 985, M4

Tab. 7: Mounting kit on rotary actuator english 21

Type 8791 REV.2

Attachment and assembly

8.3.1

Installation

WARNING!

Risk of injury from improper installation.

▶ Installation may be carried out by authorised technicians only and with the appropriate tools.

Risk of injury from unintentional activation of the system and an uncontrolled restart.

▶ Secure system from unintentional activation.

▶ Following assembly, ensure a controlled restart.

Procedure:

→ Specify the attachment position of the positioner:

- parallel to the actuator or

- rotated by 90° to the actuator.

→ Determine home position and direction of rotation of the actuator.

Anti-twist safeguard:

Note the flat side of the axle!

One of the setscrews must be situated on the flat side of

the axle as an anti-twist safeguard (see “Fig. 13”).

→ Connect adapter with 2 setscrews.

① to the axle of the positioner and secure

→ Secure setscrews with self-locking nuts to prevent them from working loose.

Angular range of the position sensor:

The maximum angular range of the position sensor is

150°. The axle of the positioner may be moved within this range only.

Rotational range of the positioner

Ideal: 90°

Minimal: 30°

Maximum: 150°

Flattened axle

The rotational movement of the rotary actuator must be within the position sensor rotational range of 150°.

Fig. 13: Angular range / anti-twist safeguard

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Type 8791 REV.2

Attachment and assembly

→ Assemble the multi-part assembly bridge * suitable for the actuator. The assembly bridge consists of 4 parts which can be adjusted to the actuator by varying the arrangement.

→ Attach the assembly bridge to the positioner using 4 hexagon bolts

③

and circlips

④

(see “Fig. 14”).

→ Place positioner with assembly bridge on the rotary actuator and attach using 4 hexagon bolts 6

(see “Fig. 15”).

①

④

③

Fig. 14: Attach assembly bridge (schematic representation)

Fig. 15: Rotary actuator attachment english 23

8.4

Remote operation with external position sensor

In the case of this model the positioner has no position sensor in the form of a rotary position sensor, but an external

Remote-Sensor.

The Remote-Sensor Type 8798 is connected via a serial, digital interface.

8.4.1

Mounting accessories

There are two options of attaching the positioner in remote oper-

ation (see “Fig. 16” ).

Installation on a standard rail with accessory kit, part no. 675702

Installation on a wall with accessory kit, part no. 675715

Type 8791 REV.2

Attachment and assembly

8.4.2

Connection and start-up of the Remote-

Sensor Type 8798

WARNING!

Risk of injury from improper start-up.

▶ Start-up may be carried out by authorised technicians only and with the appropriate tools.

Risk of injury from unintentional activation of the system and an uncontrolled restart.

▶ Secure system from unintentional activation.

▶ Following assembly, ensure a controlled restart.

→ Connect the 4 wires of the sensor cable to the designated

screw-type terminals of the positioner (see chapter “10.3.5

Terminal assignment for connecting the external position sensor (for remote model only)”).

→ Attach Remote-Sensor on the actuator.

The correct procedure is described in the brief instructions for the Remote-Sensor.

→ Connect positioner pneumatically to the actuator.

→ Connect compressed air to positioner.

→ Switch on supply voltage to the positioner.

→ Run the X.TUNE

function.

Fig. 16: Attachment types in remote operation

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Type 8791 REV.2

Fluid connection

9 FLUID CONNECTION

9.1 Connection of devices for the Ex area

When connecting devices in the potentially explosive atmosphere, observe the “Additional information for use in the potentially explosive area“ enclosed with the Ex-devices.

9.2 Safety instructions

DANGER!

Risk of injury from high pressure in the equipment/device.

▶ Before working on equipment or device, switch off the pressure and deaerate/drain lines.

WARNING!

Risk of injury from improper installation.

▶ Installation may be carried out by authorized technicians only and with the appropriate tools.

Risk of injury from unintentional activation of the system and an uncontrolled restart.

▶ Secure system from unintentional activation.

▶ Following installation, ensure a controlled restart.

Working connection 2

(connection: A2)

Supply pressure connection

1.4 – 7 bar (connection: P)

Working connection 1

(connection: A1)

Deaeration connection

Fig. 17: Fluid installation / Location of the connections

Procedure:

→ Apply supply pressure (1.4 – 7 bar) to the supply pressure connection P.

For single-acting actuators (control function A or B):

→ Connect one working connection (A1 or A2, depending on required safety end position) to the chamber of the singleacting actuator.

Safety end positions see chapter “9.3 Safety end positions” .

→ Seal a working connection which is not required with a plug.

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For double-acting actuators (control function I):

→ Connect working connections A1 and A2 to the respective chambers of the double-acting actuator.

Safety end positions see chapter “9.3 Safety end positions”

Important information for perfect control behavior.

This ensures that the control behavior is not extremely negatively affected in the upper stroke range on account of too little pressure difference.

▶ keep the applied supply pressure at least 0.5 – 1 bar above the pressure which is required to move the pneumatic actuator to its end position.

If fluctuations are greater, the control parameters measured with the X.TUNE

function are not optimum.

▶ during operation keep the fluctuations of the supply pressure as low as possible (max. ±10%).

Type 8791 REV.2

Fluid connection

9.3 Safety end positions

The safety end position after failure of the electrical auxiliary power depends on the fluid connection of the actuator to the working connections A1 or A2.

9.3.1 Single-acting actuators

Actuator system

Safety end positions after failure of the electrical aux iliary power pneumatic auxiliary power down up

→ Connection according to

“Fig. 18”

up down

Control function A

→ Connection according to

“Fig. 19”

up up

→ Connection according to

“Fig. 18”

down down

Control function B

→ Connection according to

“Fig. 19”

Tab. 8: Safety end positions, single-acting actuators down up

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Type 8791 REV.2

Fluid connection

Single-acting actuator - control function A or B

A 2

Connection: working connection A1 to actuator

A2 sealing

Fig. 18: Connection A1

A 2

Connection: working connection A2 to actuator

A1 sealing

Fig. 19: Connection A2

9.3.2 Double-acting actuators

Actuator system

Safety end positions after failure of the electrical aux iliary power pneumatic auxiliary power

→ Connection

see “Fig. 20”

upper chamber lower chamber up up = lower chamber of the actuator to A2 not defined down

Control function I down = upper chamber of the actuator to A2

Tab. 9: Safety end positions - double-acting actuators

Double-acting actuators - control function I

A 2

Working connection A1 and A2 to actuator

Safety end position: up = lower chamber to A2 down = upper chamber to A2

Fig. 20: Connection with control function I english 27

10 ELECTRICAL CONNECTION

All electrical inputs and outputs of the device are not galvanically isolated from the supply voltage.

10.1

Connection of devices for the Ex area

When connecting devices in the potentially explosive atmosphere, observe the “Additional information for use in the potentially explosive atmosphere“ enclosed with the Ex-devices.

10.2

Safety instructions

DANGER!

Risk of electric shock.

▶ Before working on equipment or device, switch off the power supply and secure to prevent reactivation.

▶ Observe applicable accident prevention and safety regulations for electrical equipment.

WARNING!

Risk of injury from improper installation.

▶ Installation may be carried out by authorized technicians only and with the appropriate tools.

Risk of injury from unintentional activation of the system and an uncontrolled restart.

▶ Secure system from unintentional activation.

▶ Following installation, ensure a controlled restart.

Type 8791 REV.2

Electrical connection

10.3

Electrical connection without fieldbus communication

10.3.1

Electrical connection with circular plug-in connector M12, 8-pin

Operating voltage and diverse signals

3 2

M12, 8-pin plug

Functional earth FE

Fig. 21: Designation of the circular plug-in connector and contacts

28 english

Type 8791 REV.2

Electrical connection

Pin assignment for operating voltage

Pin Wire color 10)

Configuration External circuit / Signal level

3 green GND

4 yellow +24 V 4

24 V DC ± 25 % max. residual ripple 10%

Tab. 10: Pin assignment; operating voltage

Pin assignment for input signals from the control centre (e.g. PLC)

Pin Wire color 10)

Configuration On the device side

External circuit / Signal level

1 white Set-point value +

(0/4 – 20 mA)

1 + (0/4 – 20 mA)

5 brown Set-point grey value GND

Digital input

GND set-point value 9) see chapter “Connection type 3-wire or 4-wire”

0 – 5 V (logical 0)

10 – 30 V (logical 1) with reference to

Pin 3 (GND)

Tab. 11: Pin assignment; input signals of the control centre

9) Factory setting: connection type 4-wire

Pin assignment for output signals to the control centre

(required for analogue output variant only)

Pin Wire

7 color red blue

10)

Configuration On the device side

8 Analogue feedback +

Analogue feedback

GND

External circuit / Signal level

+ (0/4 – 20 mA)

GND (identical with the

GND operating voltage)

Tab. 12: Pin assignment; output signals to the control centre

10) The indicated wire colors refer to the connection cable, order no.

919061, available as an accessory english 29

10.3.2

Connection type 3-wire or 4-wire

Setting via communication software

Connection type 4-wire (factory setting)

The set-point value input is designed as a differential input, i.e. the GND lines of the set-point value input and the supply voltage are not identical.

Note: If the GND signals of the set-point value input and the supply voltage are connected, the 3-wire connection type must be set in the software.

11 11)

1 12)

0/4 – 20 mA

2 12)

11)

81 11)

3 12)

GND

+24 V DC

82 11)

4 12)

Tab. 13: Connection type 4-wire

Type 8791 REV.2

Electrical connection

Connection type 3-wire

The set-point value input is related to the GND line of the supply voltage, i.e. setpoint input and supply voltage have a common GND line.

+ 11 13)

1 14)

0/4 – 20 mA

3 14)

13)

82 13)

4 14)

GND

+24 V DC

Tab. 14: Connection type 3-wire

11) For connection with cable gland

12) For connection with round plug connector

30 english

13) For connection with cable gland

14) For connection with round plug connector

Type 8791 REV.2

Electrical connection

10.3.3

Electrical connection with cable gland

32 –

–

+24 V

GND

11 +

12 –

31 +

Fig. 22: Designation of the screw-type terminals

10.3.4

Connection of the terminals

→ Unscrew the 4 screws on the housing cover and remove the housing cover.

The screw-type terminals are now accessible.

→ Connect terminals according to the configuration.

Terminal assignment for input signals from the control centre

(e.g. PLC)

Terminal Configuration On the device side

11 + Set-point value +

11 +

External circuit / Signal level

+ (0/4 – 20 mA)

12 –

81 +

Set-point value GND

Digital input +

12 –

81 +

GND set-point value 15) see chapter “Connection type 3-wire or 4-wire”

0 – 5 V (logical 0)

10 – 30 V (logical 1)

82 – Digital input – 82 –

GND (identical with the

GND operating voltage)

Tab. 15: Terminal assignment; input signals of the control centre

15) Factory setting: connection type 4-wire english 31

Terminal assignment for output signals to the control centre

(required for analogue output variant only)

Terminal Configuration On the device side

31 + Analogue feedback +

31 +

External circuit / Signal level

+ (0/4 – 20 mA)

32 –

Analogue feedback

GND

32 –

GND (identical with the

GND operating voltage)

Tab. 16: Terminal assignment; output signals to the control centre

Terminal assignment for operating voltage

Terminal Configuration External circuit / Signal level

+24 V

GND

Operating voltage +

Operating voltage GND

+24 V

GND

24 V DC ± 25 % max. residual ripple

10%

Tab. 17: Terminal assignment; operating voltage

Type 8791 REV.2

Electrical connection

10.3.5

Terminal assignment for connecting the external position sensor (for remote model only)

Terminal Configuration

On the device side

External circuit / Signal level

S +

Supply sensor +

S + +

S –

Supply sensor –

S – –

Serial interface, A cable

Serial interface,

B-cable

A-line

B-line

16) Assignment of the wire color see “Tab. 19”

Remote

Sensor

Type

8798 16)

Tab. 18: Terminal assignment; external position sensor

Positioner

Terminal

Wire color Remote-

Sensor with cable type 1

Wire color Remote-

Sensor with cable type 2

S +

S –

A brown white green brown black red

B yellow orange

Tab. 19: Assignment of the wire color (Remote-Sensor)

32 english

Type 8791 REV.2

Electrical connection

10.4

Electrical installation, IO-Link

Plug M12 x 1, 5-pin

Fig. 23: Pin assignment

2 4

M8 socket, 4-pin

(remote variant only)

Pin Designation Configuration

1 L +

2 P24

3 L –

24 V DC

0 V (GND)

4 C/Q

5 M24

Tab. 20: Pin assignment

IO-Link

0 V (GND)

System supply

Actuator supply

System supply

Actuator supply

The pin assignment of the remote variant can be found in chapter “10.3.5”

10.5

Electrical installation, büS

Plug M12 x 1, 5-pin

Fig. 24: Pin assignment

2 4

M8 socket, 4-pin

(remote variant only)

Pin Wire color Configuration

1 CAN plate/shielding CAN plate/shielding

2 red +24 V DC ±25 %, max. residual ripple 10 %

3 black

4 white

GND / CAN_GND

CAN_H

5 blue

Tab. 21: Pin assignment

CAN_L

For electrical installation with büS network, note:

Use a 5-pin round plug and shielded 5-core cable.

The shielding is capacitively connected to the functional earth via the device.

The pin assignment of the remote variant can be found in chapter “10.3.5” english 33

10.6

Pin assignment for connecting the external position sensor (remote variant)

Pin Configuration

On the device side

External circuit / Signal level

Supply sensor +

Supply sensor –

S +

S –

Serial interface,

A cable

–

A-line

Remote

Sensor

Type

8798

Serial interface,

B-cable

B B-line

Tab. 22: Pin assignement, M8 socket, 4-pin

Type 8791 REV.2

Start-up

11 START-UP

11.1

Safety instructions

WARNING!

Risk of injury from 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 familiar with and completely understand the contents of the operating instructions.

▶ Observe the safety instructions and intended use.

▶ Only adequately trained personnel may operate the equipment/the device.

11.2

Specifying the standard settings

The basic settings of the positioner are implemented at the factory.

To adjust the positioner to local conditions, the X.TUNE

function must be run following installation.

34 english

Type 8791 REV.2

Start-up

11.2.1

Running the automatic adjustment X.TUNE

WARNING!

Danger due to the valve position changing when the X.TUNE

function is running.

When the X.TUNE

is running under operating pressure, there is an acute risk of injury.

▶ Never run X.TUNE

while a process is running.

▶ Take appropriate measures to prevent the equipment from being accidentally actuated.

NOTE!

Avoid maladjustment of the controller due to an incorrect supply pressure or applied operating medium pressure.

▶ Run X.TUNE

whenever the supply pressure (= pneumatic auxiliary energy) is available during subsequent operation.

▶ Run the X.TUNE

function preferably without operating medium pressure to exclude interference caused by flow forces.

→ Unscrew the 4 screws on the housing cover and remove the housing cover.

To run X.TUNE

, the positioner must be in the AUTOMATIC operating state

(DIP switch 4 = OFF).

→ Start X.TUNE

by pressing button 1 for 5 sec 17) .

LED 2 flashes at 5 Hz. The device is in the NAMUR status function check, LED 1 lights orange.

If the X.TUNE is successfully completed, the NAMUR status is reset again. The changes are automatically transferred to the memory

(EEPROM) provided the X.TUNE function is successful.

When LED 1 lights red after X.TUNE:

→ Execute X.TUNE again.

→ Perform a device restart if necessary.

17) The X.TUNE can also be started via communications software.

11.3

Setting with Bürkert Communicator

The Bürkert Communicator can be used to make all settings on the device.

The settings in the Bürkert Communicator can be found in the operating manual.

11.3.1

Connecting IO-Link device with Bürkert

Communicator

Required components:

• Communications software: Bürkert Communicator for PC

• USB-büS interface set (see accessories)

• büS adapter for büS service interface (see accessories)

• If necessary, a büS cable extension (see accessories) english 35

→ To connect the IO-Link device to the Bürkert Communicator, unscrew the housing cover.

→ Insert micro USB plug in communication interface.

→ Establish connection to PC with USB-büS interface set.

→ Starting Bürkert Communicator.

→ Implementing settings.

Button 1

DIP Switches

LED 1

LED 2

Button 2

Communications interface

Fig. 25: Description of control elements

11.3.2

Connecting büS device with Bürkert

Communicator

Required components:

• Communications software: Bürkert Communicator for PC

• USB-büS interface set (see accessories)

→ Establish connection to PC with USB-büS interface set.

→ Starting Bürkert Communicator.

→ Implementing settings.

36 english

Type 8791 REV.2

Start-up

11.4

IO-Link

11.4.1

Information, IO-Link

IO-Link is an internationally standardized IO technology (IEC

61131-9) to enable sensors and actuators to communicate.

IO-Link is a point-to-point communication with 3-wire connection technology for sensors and actuators and unshielded standard sensor cables.

To ensure clear communication, the IO-Link devices should not be parameterised simultaneously by the higher-level controller

(PLC) via the IO-Link master and with the Bürkert Communicator

(via the service interface).

11.4.2

Technical specifications, IO-Link

IO-Link specifications V1.1.2

Supply via IO-Link (M12 x 1, 5-pin, A-coded)

Port Class B

SIO mode no

IODD file see Internet

VendorID 0x0078, 120

DeviceID see IODD file

ProductID 8791

Transmission speed COM3 (230.4 kbit/s)

PD Input Bits 80

PD Output Bits 40

M-sequence Cap. 0x0D

Type 8791 REV.2

Accessories

Min. cycle time 5 ms

Data storage Yes

Max. cable length 20 m

11.4.3

Configuration of the fieldbus

The required start-up files and the description of the process data and acyclic parameters are available on the Internet.

Download from: www.burkert.com

/ Type 8791 / Software

11.5

büS

11.5.1

Information, büS

büS is a system bus developed by Bürkert with a communication protocol based on CANopen.

11.5.2

Configuration of the fieldbus

The required start-up files and the description of objects are available on the Internet.

Download from: www.burkert.com

/ Type 8791 / Software

12 ACCESSORIES

Designation

Connection cable M12 x 1, 8-pin

Communication software Bürkert

Communicator

Tab. 23: Accessories

Order no.

919061

Information at www.burkert.com

USB-büS interface set:

USB-büS interface set 2 (büS stick + 0.7 m cable with M12 plug) büS adapter for büS service interface

(M12 on büS service interface Micro-USB) büS cable extension (M12 pin to M12 socket), length 1 m büS cable extension (M12 pin to M12 socket), length 3 m büS cable extension (M12 pin to M12 socket), length 5 m büS cable extension (M12 pin to M12 socket), length 10 m

Tab. 24: Accessories

772551

773254

772404

772405

772406

772407 english 37

12.1

Communications software

The PC operating program “Communicator” is designed for communication with the devices from the Bürkert positioner family.

If you have any questions regarding compatibility, please contact the Bürkert Sales Center.

A detailed description and precise schedule of the procedure for the installation and operation of the software can be found in the associated documentation.

Download the software at: www.burkert.com

Type 8791 REV.2

Packaging, transport, storage

13 PACKAGING, TRANSPORT,

STORAGE

NOTE!

Transport damages.

Inadequately protected equipment may be damaged during transport.

▶ During transportation protect the device against moisture and dirt in shock-resistant packaging.

▶ Follow the allowable storage temperature.

Incorrect storage may damage the device.

▶ Store the device in a dry and dust-free location.

▶ Storage temperature -20 – +65 °C.

Damage to the environment caused by device components contaminated with media.

▶ Dispose of the device and packaging in an environmentally friendly manner.

▶ Observe applicable regulations on disposal and the environment.

38 english

www.burkert.com

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