Type 8681 Control Head Operating Instructions
We reserve the right to make technical changes without notice. Technische Änderungen vorbehalten. Sous resérve de modification techniques.
Control Head Type 8681 Control Head Type 8681 Inhalt 1. Operating Instructions........................................................................................................................................................8 2. Authorized use..............................................................................................................................................................................9 2.1. Export Restrictions..........................................................
Control Head Type 8681 7. Installation....................................................................................................................................................................................23 7.1. Safety instructions..............................................................................................................................................................23 7.2. Assembly of the Control Head......................................................................
Control Head Type 8681 11.5. Design Aid...............................................................................................................................................................................42 11.6. Safety instructions..............................................................................................................................................................43 11.7. Electrical installation AS Interface................................................................
Control Head Type 8681 13.3. Design Aid...............................................................................................................................................................................62 13.4. Safety instructions..............................................................................................................................................................63 13.5. Electrical Installation / Start-up..................................................................
Control Head Type 8681 20. Spare Parts.....................................................................................................................................................................................87 21. Shutdown.........................................................................................................................................................................................88 21.1. Safety instructions..............................................................
Control Head Type 8681 Operating Instructions 1. Operating Instructions The 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. Warning! The operating instructions contain important safety information! Failure to observe these instructions may result in hazardous situations. • The operating instructions must be read and understood.
Control Head Type 8681 Authorized use 2. Authorized use Non-authorized use of the Control Head Type 8681 may be a hazard to people, nearby equipment and the environment. • The Control Head has been designed for use as actuation of pneumatically operated process valves and / or for recording the switching states of these. • Use according to the authorized data, operating conditions and conditions of use specified in the contract documents and operating instructions. These are described in the chapter 6.
Control Head Type 8681 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. Danger! Danger – high pressure! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Basic Safety Instructions Note! Connection of the Control Head Do not connect any mechanically rigid connection parts, in particular those with long lever arms, as such connections could generate torques that might damage the control head.
Control Head Type 8681 Basic Safety Instructions 4. General Information 4.1. Contact address Bürkert Fluid Control Systems Sales Center Christian-Bürkert-Straße 13-17 D-74653 Ingelfingen Tel. : Fax: +49 7940 10 91 111 +49 7940 10 91 448 E-mail: info@de.buerkert.com Homepage: www.buerkert.com, www.buerkert.de 4.2. Warranty The warranty is only valid if the control head is used as intended in accordance with the specified application conditions. 4.3.
Control Head Type 8681 System Description 5. System Description 5.1. Intended Application Area The Control Head Type 8681 has been designed for use as actuation of pneumatically operated process valves and / or for recording the switching states of these. 5.2. General Description The Control Head Type 8681 is used for actuating pneumatically operated process valves. For process valve actuation, the control head can be equipped with up to three solenoid valves.
Control Head Type 8681 System Description • short mechanical and pneumatic installation times. • For increased safety requirements (e.g. in the explosion-risk area) a seal or a hood safeguard using plastic selfcutting screws (3 mm diameter, approx. 10 mm length; e.g. Ejot PT screws K 30 x 10) are required. • conform to the ATEX Directive 94/9/EC (Dust ATEX category 3D and Gas ATEX category 3G - see chapter 6.2. ) 5.4. Functions / Options / Designs 5.4.1.
Control Head Type 8681 System Description 5.4.2. Fluid diagram Control Head Type 8681 - Fluid diagram (with restriction capability for each solenoid valve): Model with three Type 6524 solenoid valves, e.g. for double-seated valve Fig. 2: Fluid diagram (model: 3 solenoid valves) The functions and designs of Control Head Type 8681 are described in the following chapters.
Control Head Type 8681 System Description 5.4.3. Number of solenoid valves The control head for process valves has been designed for single-acting and double-acting valve actuators as well as for double-seated and multi-position valves.
Control Head Type 8681 System Description 5.4.6. Position Measuring System The switching positions of the process valves are reported to the higher-level control by feedback signals from the contactless position measuring system. Connection to the control head is done by means of a simple adaptation to the process valve's piston. The recordable stroke range is between 0 and 80 mm.
Control Head Type 8681 Technical Data 6. Technical Data 6.1. Operating Conditions Danger! Danger of explosion in explosive atmosphere (only in the event of a fault as zone 2)! • Do not expose the device to any mechanical or thermal loads that will exceed the limits described in the operating instructions. Warning! Risk of injury from overheating of the control head. Heating above the permitted temperature range can endanger people, the device and the environment.
Control Head Type 8681 Technical Data 6.3. Mechanical data M16x1.5 (2x) Cover safeguard: - Seal max Ø2 and / or - plastic self-cutting screw 3.0x10 G1/4 (2x) G1/8 (3x) Fig. 3: Dimensional drawing Weight: ca. 0.
Control Head Type 8681 Technical Data 6.4. Pneumatic Data Control medium: oil-free and dry air, neutral gases Quality classes in accordance with DIN ISO 8573-1 (5 µm filter recommended) Dust content Quality class 5: max. particle size 40 μm, max. particle density 10 mg/m3 Water content Quality class 3: max. pressure dew point -20 °C or min. 10 °C below the lowest operating temperature Oil content Quality class 5: max.
Control Head Type 8681 Technical Data 6.5. Position Measuring System Data Stroke range (measuring range): Resolution: Total fault: 0 ... 80 mm ≤ 0.1 mm ± 0.5 mm - when using a target in accordance with the dimensional drawing, Material 1.4021 and a piston rod (Ø 22 mm, Material - see (*)) (Fault refers to the reproducibility of a taught position) The illustration in Fig. 5 shows the dimensional relationships between the control head and the piston with a target.
Control Head Type 8681 Technical Data 6.6. Factory Settings in the Firmware The control head is supplied with the following factory settings of the firmware: The service interface may only be used in non-explosive atmosphere. Feedback areas (position measuring system): (A feedback area is the area, within which a position (e.g. S1) is reported back.) Signal Feedback area, top Feedback area, bottom Factory setting [mm] Adjustment range [mm] Factory setting [mm] Adjustment range [mm] S1 + 3.
Control Head Type 8681 Installation 7. Installation 7.1. Safety instructions DANGER! Risk of injury from high pressure in the equipment! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Installation screws M5), which engage in the middle groove of the hub flange (protection against pulling off). The control head can radially slide into any position in 360° arc, seamlessly. The hub flange and non ferromagnetic piston rod with the target that is used to record the position must comply with the specifications with regard to material and stability (see chapter 6.5. Position Measuring System Data. Control head Target made of 1.4021 Piston rod (*) (max.
Control Head Type 8681 Installation →→Check the secure fit of the sealing rings (in the upper and lower grooves). →→Mount the control head on the hub flange (seamlessly 360° rotatable). →→Secure control head with the two locking screws (shoulder screws M5) in the middle groove of the hub flange to prevent pulling off from the hub flange – tightening torque: max. 3.2 Nm (see Fig. 7: Dimensional diagram of the control head - process valve adaptation and 7.2.3. Realignment of the Control Head). 7.2.3.
Control Head Type 8681 Opening and Closing the Housing 8. Opening and Closing the Housing 8.1. Safety instructions DANGER! Risk of injury from high pressure in the equipment! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Opening and Closing the Housing 8.2.2. Closing the Housing If necessary, clean the seal contour of the seal and of the hood, and lightly lubricate it using a recommended silicone grease (e.g. Paraliq GTE 703).
Control Head Type 8681 Pneumatic Installation 9. Pneumatic Installation 9.1. Safety instructions DANGER! Risk of injury from high pressure in the equipment! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Pneumatic Installation Procedure: →→If necessary, realign the control head (see chapter 7.2.3. Realignment of the Control Head) →→A silencer has already been mounted on the Exhaust Air Connection (3/R) in the supplied state. As needed, the silencer can be replaced by an exhaust air hose (e.g. after screwing in an appropriate plug-in hose connectors).
Control Head Type 8681 Pneumatic Installation Settings of the Flow-Rate or the Control Speed with the Help of the Flow Restriction Screws: →→Open the housing observing the notes contained in chapter 8. Opening and Closing the Housing. →→For proper setting, it is advisable to turn the two flow restriction screws initially into the minimum flow-rate position. The process valve will then initially move slowly so that you have more time to find the optimum setting during a switching operation.
Control Head Type 8681 24 V DC - Design 10. 24 V DC - Design 10.1. Electrical connection options The following connection concepts are available for the electrical connection of the control head: Cable gland Cable gland with multi-pole connection (M12 plug according to IEC 61076-2-101, 12-pole) Connection left: Voltage, signals Connection left: Voltage, signals Connection right: external initiator Connection right: external initiator Fig. 10: 10.2.
Control Head Type 8681 24 V DC - Design Solenoid valves: Power input per solenoid valve: Power consumption per solenoid valve: Operating mode: max. 0.8 W (0.9 W during activation) 67 mA at 12 V DC 34 mA at 24 V DC 29 mA at 28 V DC Long-term operation (100 % ED) Central display of the switching states: 4 2 mA with a power supply of 24 V DC per illuminated display; Color switching see chapter 16.
Control Head Type 8681 24 V DC - Design 10.3. Design Aid Power consumption of the electronics: PEl = 0.7 W or I El = 30 mA at 24 V IValve-On = 38 mA at 24 V IValve = 34 mA at 24 V I LED = 42 mA at 24 V Power consumption of a valve during activation (200 ms): PValve-On = 0.9 W or Power consumption of a valve after reduction: PValve = 0.8 W or Power consumption of an optical position report: PLED = 1.
Control Head Type 8681 24 V DC - Design 10.4.
Control Head Type 8681 24 V DC - Design Note! Use of the Control Head in Explosive Atmosphere • Only use cables and cable glands that are allowed for the respective application area, and mount the cable gland according to the respective operating instructions! • Close all unnecessary openings with lock screws/plugs approved for explosions area! 24 V DC Electronics Module, Terminal Strip Configuration: Teach-In buttons T1-3 Solenoid valve connection with status LED for Valve 1 Service interface Terminal s
Control Head Type 8681 24 V DC - Design Circuit diagram 24 V DC: *) Order variant "Analog": output - analog signal Fig.
Control Head Type 8681 24 V DC - Design 10.5.2. Multi-pole Connection Internal cabling work is not required for models with multi-pole connection, which makes installation and start-up on site considerably easier and quicker, reducing the risk of leaks. However, you will require the correspondingly assembled cable sets with the following pin assignments: Input and output signals to the higher-level control (PLC): 12-pole circular plug-in connector M12 x 0.75 - male (acc.
Control Head Type 8681 AS Interface - Design 11. AS Interface - Design 11.1. Definition AS Interface Connection AS interface (Actuator Sensor Interface) is a field bus system which is used primarily for networking binary sensors and actuators (slaves) with a higher-level control (master). Connecting the control heads to higher bus systems is possible using commercially available gateways. Contact your distribution partner in this regard.
Control Head Type 8681 AS Interface - Design 11.2. Electrical Connection Options for AS Interface The following connection concepts are available for the electrical connection of the control head: • Cable gland with multi-pole connection on a cable (8 cm length) • Cable gland with multi-pole connection on a cable (80 cm length) with multi-pole connection (M12 plug according to IEC 61076-2-101, 4-pole) on 8 cm cable left: AS interface right: Fig. 14: 11.3.
Control Head Type 8681 AS Interface - Design Table of calculated line length of the control head versions: When designing the system, consider the length of the round cable leading directly to the control head (see following table and example calculation). Model Calculated line length (incl. internal cabling) Multi-pole (cable 8 cm) 0.3 m Multi-pole (cable 80 cm) 1.0 m Example: for multi-pole connection with 8 cm cable: The AS interface cable harness may still be 81.4 m (100 m - 62 * 0.
Control Head Type 8681 AS Interface - Design Connections: Multi-pole connection version 1 x M16 x 1.5 cable gland / A/F19 with multi-pole connection (M12 plug according to IEC 61076-2-101, 4-pole on a cable of 8 or 80 cm length for power supply and signal) 1 x M16 x 1.5 cable gland / A/F19 for external initiator clamping area 3 to 6 mm, with dummy plugs with screw terminals for cable cross-sections 0.14 to 1.5 mm² Power supply: 29.5 to 31.
Control Head Type 8681 AS Interface - Design Note! If all three solenoid valves are simultaneously controlled via the AS interface, the electronics will activate the valves sequentially with a 200 ms time delay to protect the AS interface from overloads. Please observe the notes on power requirement and maximum expansion stage of the AS interface network contained in chapter 11.3.
Control Head Type 8681 AS Interface - Design Calculation Examples: Example 1: 3 valves are activated simultaneously, one position is reported (state for 200 ms): PSlave = PEl + 1 x PValve-On + 2 x PValve + 1 x PLED 4.5 W = 1.0 W + 1 x 0.9 W + 2 x 0.8 W + 1 x 1.
Control Head Type 8681 AS Interface - Design 11.7. Electrical installation AS Interface Internal cabling work is not required for any of the AS Interface designs with multi-pole connection, which makes installation and start-up on site considerably easier and quicker, reducing the risk of leaks. However, you will require the correspondingly assembled cable sets with the following pin assignments. Likewise, the jumpers on the electronics module must be set correspondingly (see figures below).
Control Head Type 8681 AS Interface - Design The cable with multi-pole connection version is especially suited for direct and flexible connection to the AS interface cable harness using the ribbon cable terminal (M12 branch circuit, VA branch circuit) that is optionally available.
Control Head Type 8681 AS Interface - Design 11.8. Programming Data The control heads have been configured as AS interface version with an extended address range (A/B slaves) for 62 slaves or optionally as an AS interface version for 31 slaves. A change between the two configurations in the control head is only possibly by exchanging the electronic PCB! If one control head is replaced with another control head having a different configuration in the AS interface field bus system (e.g.
Control Head Type 8681 DeviceNet - Design 12. DeviceNet - Design 12.1. Definition • The DeviceNet is a field bus system which is based on the CAN protocol (Controller Area Network). It enables actuators and sensors (slaves) to be networked with higher-level controllers (master). • The control head in the DeviceNet is a slave device according to the Predefined Master/Slave Connection Set stipulated in the DeviceNet specification.
Control Head Type 8681 DeviceNet - Design Inputs 3 discrete feedback signal of the position measuring system (positions S1 - S3) 1 discrete feedback signal of the external initiator (S4) 1 analog position signal in mm supply via DeviceNet string (11 to 25 V DC) Switch level high signal ≥ 5 V Switch level low signal ≤ 1.5 V Outputs 3 solenoid valves Power consumption from the bus: max. output 5 W, if all valves are switched (3 x type 6524 with 0.8 W each) 12.3.1.
Control Head Type 8681 DeviceNet - Design 12.4. Electrical Data Connections: "Multi-pole" 1 x M16 x 1.5 cable gland / SW22 with multi-pole connection (M12 plug according to IEC 61076-2-101, 5-pole on a cable of 80 cm length ) for DeviceNet bus and power supply 1 x M16 x 1.5 cable gland / SW19 for external initiator clamping area 3 to6 mm, with dummy plugs with screw terminals for cable cross-sections 0.14 to 1.
Control Head Type 8681 DeviceNet - Design 12.6. Design Aid Power consumption of the electronics: PEl = 1.44 W or I El = 60 mA at 24 V IValve-ON = 42 mA at 24 V IValve = 34 mA at 24 V I LED = 42 mA at 24 V Power consumption of a valve during activation (200 ms): PValve-ON = 1.0 W or Power consumption of a valve after reduction: PValve = 0.8 W or Power consumption of an optical position report: PLED = 1.
Control Head Type 8681 DeviceNet - Design 12.7.
Control Head Type 8681 DeviceNet - Design DeviceNet electronics module: Solenoid valve connection with status LED for Valve 1 Teach-In buttons T1-3 Service interface DIP switches for setting the address and baud rate DIP switches for color coding the LEDs Status LED for device Status LED for network Solenoid valve connection with status LEDs for Valves 2 & 3 DeviceNet power supply Connection for the external initiator Bus signals Fig.
Control Head Type 8681 DeviceNet - Design 12.9. Network Topology of a DeviceNet System When installing a DeviceNet system, ensure that the terminating circuit of the data lines is correct. The circuit prevents the occurrence of interference caused by signals reflected onto the data lines. The trunk line must be terminated at both ends with resistors of 120Ω and 1/4 W power loss (see "Fig. 21: Network topology"). Fig. 21: illustrates a line with one trunk line and several drop lines.
Control Head Type 8681 DeviceNet - Design 12.10.1.
Control Head Type 8681 DeviceNet - Design 12.10.2. Setting the baud rate Adjustment of the control head to the baud rate of the network. Baud rate DIP 7 DIP 8 125 kbaud off off 250 kbaud on off 500 kbaud off on (on) (on) not permitted: If the settings are changed by actuating the DIP switches, this change will not take effect until the device is restarted.
Control Head Type 8681 DeviceNet - Design The addresses listed in the table above ("Static input assemblies") can be used as a path data for the attribute Produced Connection Path of an I/O connection. Nevertheless, by using this address data, the attributes combined in the assemblies can also be accessed acyclically via Explicit Messages. 12.11.2. Static Output Assembly Name Address of data attribute of the assemblies for read access.
Control Head Type 8681 DeviceNet - Design 12.12.2. Configuration example The example describes the principle procedure when configuring the device using the software RSNetWorx for DeviceNet (Rev. 4.21.00). Installation of the EDS File The EDS file is installed with the aid of the EDS Installation Wizard Tool associated with RSNetWorx. During the installation procedure the icon can be assigned (if this does not occur automatically).
Control Head Type 8681 DeviceNet - Design Online Parameterization of the Device Devices can also be parameterized online. In doing so, you can also select whether only individual parameters (single) or all parameters (all) of a group are read from the device (upload) or are loaded into the device (download). It is also possible to transfer individual parameters or all parameters of a group cyclically in monitor mode. This may be helpful particularly for start-up purposes. 12.13.
Control Head Type 8681 DeviceNet - Design 12.13.2. State of bus status LED "Network" LED Device state Explanation Troubleshooting Off No voltage / not online • Device is not supplied with voltage • Connect other devices, if the device is the only network subscriber, • Device has still not ended Duplicate MAC ID Test (test lasts approx. 2 s) • Device cannot end Duplicate MAC ID Test.
Control Head Type 8681 120 V AC - Design 13. 120 V AC - Design 13.1. Electrical connection options Cable gland: Fig. 24: 13.2. Connection left: Voltage, signals Connection right: external initiator Connection concept 120 V AC Electrical Data Central power supply: 110 to 130 V AC, 50/60 Hz Connections: Cable gland 1 x M16 x 1.5 cable gland / SW22 for power supply and signals clamping area 5 to 10 mm, with dummy plugs with screwterminals for cable cross-sections of 0.5 to 1.
Control Head Type 8681 120 V AC - Design Feedback signal output: S4 out is directly connected to S4 in Input / proximity switches (external initiator: S4 in): Power supply: voltage present at control head U Nominal = 120 V AC, 50/60 Hz Current carrying capacity, sensor power supply: max. 0.
Control Head Type 8681 120 V AC - Design 13.3. Design Aid Power consumption of the electronics: PEl = 1.2 VA or I El = 10 mA at 120 VA IValve-ON = 14 mA at 120 VA IValve = 12 mA at 120 VA I LED = 13 mA at 120 VA Power consumption of a valve during activation (200 ms): = PValve-ON 1.7 VA or Power consumption of a valve after reduction: = PValve 1.4 VA or Power consumption of an optical position report: = PLED 1.
Control Head Type 8681 120 V AC - Design 13.4. Safety instructions DANGER! Risk of injury due to electrical shock (110 ...
Control Head Type 8681 120 V AC - Design DANGER! Risk of electric shock if the PE connection is not connected! • the PE connection must be connected! →→Clamp the protective conductor to the PE connection. →→Check correct grounding. →→Close the housing observing the notes contained in chapter "8. Opening and Closing the Housing". Note! Ensure IP protection! • To ensure IP protection, the union nuts of the cable glands must be tightened in accordance with the cable sizes or dummy plugs used (approx. 1.
Control Head Type 8681 120 V AC - Design Designation Terminal strip Configuration Designation Terminal strip Configuration for external initiator PE Protection earth protective conductor L Electrical power supply live conductor L live conductor S4 IN External initiator input N neutral conductor N Electrical power supply neutral conductor S1 OUT Output position 1 S2 OUT Output position 2 S3 OUT Output position 3 S4 OUT External initiator output Y1 Solenoid valve 1 input Y2 Solenoi
Control Head Type 8681 Connection of an External Initiator 14. Connection of an External Initiator DANGER! Danger of explosion in explosive atmosphere (only in the event of a fault as zone 2)! • Opening the hood or the housing in an explosive atmosphere is only allowed in the isolated state! An external initiator can be connected using the small 3-pin screw terminal - according to the respective design (see e.g. Fig. 25 and the respective chapter "Electrical Installation").
Control Head Type 8681 Position Measuring System 15. Position Measuring System The switching positions of the process valve are reported to the higher-level control by feedback signals from the contactless position measuring system. Connection to the control head is done by means of a simple adaptation to the process valve's piston. The recordable stroke range is between 0 and 80 mm.
Control Head Type 8681 Position Measuring System →→If necessary, return control head and system to normal state (switching position, power supply). →→Close the housing observing the notes contained in chapter 8. Opening and Closing the Housing. If the piston or the target are located outside the measuring area during the teaching phase, the LED will flash 3 times in the defined fault color. If the piston or target are outside of the measuring area, no positions signals will report back, i.e.
Control Head Type 8681 Position Measuring System 15.2.2. Autotune functions Teach-In button T2 + T3 Mode Activation duration Autotune mode opt. feedback green + yellow + red 2.5s + continuously on Teach-In button Function T1 Autotune 1 T2 Autotune 2 T3 Autotune 3 T1 + T2 Autotune 4 T1 + T3 Autotune 5 T2 + T3 Autotune 6 Activation duration opt. feedback 0.5s green + yellow + red chaser mode The Autotune function can be selected after changing to Autotune mode.
Control Head Type 8681 Position Measuring System - Then position S2 is taught. - After that, valve V1 is deactivated. It initiates closing of the process valve. - Once the process valve is closed (after 15 s maximum), position S1 is displayed by LED. 4. Autotune sequence 1 is complete: positions S1 and S2 have been taught. In the event that a Timeout occurs, the corresponding Autotune function will be exited and switched to normal operation.
Control Head Type 8681 Position Measuring System Autotune 4: Control Effect on the process valve T2 + T3 Autotune mode starts T1 + T2 Autotune 4 starts Valve closing internal program Error Activate V2 Wait period 10s Closed position Teach T1 Valve opens Deactivate V2 Activate V1 Wait period 10s Open position Teach T2 Valve closing Deactivate V1 Activate V2 Valve closes Wait on position S1 S1 Neutral position Deactivate V2 Timeout 15s Autotune mode completed Autotune 5:
Control Head Type 8681 LED - Color Assignments 16. LED - Color Assignments The switching states of the feedback positions are signaled centrally to the outside by super-bright LEDs so that quick visual control is possible also for large systems. The color assignments for all signals to the process valve states corresponds to the subsequently listed tables.
Control Head Type 8681 LED - Color Assignments 16.1.
Control Head Type 8681 LED - Color Assignments Blinking patterns ON OFF 250 ms 250 ms Note Permanent blinking in the fault color: - Teaching does not occur or - Teach-Reset has been performed or - Bus error Permanent blinking in the color for that position: Signal from position 3 16.3.
Control Head Type 8681 Service Mode / Manual Control 17. Service Mode / Manual Control By default, the control head provides the following (e.g. for service purposes): • a magnetic manual control that is easily accessible from the outside for Solenoid Valve 1 (2/A1), as well as • a mechanical manual control accessible when the hood is open on each equipped solenoid valve. 17.1. Magnetic Manual Control Markings for magnetic manual control Magnetic Manual Control Fig.
Control Head Type 8681 Service Mode / Manual Control Procedure for activating & deactivating the manual control for valve location 2/A1: →→Observe safety guidelines for the system prior to using the manual control. →→Activating the magnetic manual control: Hold the manual control tool on the identification points between the cable glands for three seconds (see Fig.
Control Head Type 8681 Maintenance, Troubleshooting 18. Maintenance, Troubleshooting 18.1. Safety instructions DANGER! Risk of injury from high pressure in the equipment! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Maintenance, Troubleshooting 18.2.
Control Head Type 8681 Maintenance, Troubleshooting 18.3. Maintenance When used properly, the Control Head Type 8681 operates maintenance and trouble-free. For service work, we offer spare part sets for certain components or modules (see chapter entitled "20. Spare Parts"). Repairs to the control head for use in explosive atmosphere, however, are only allowed by the manufacturer. If service function is active (see chapter 6.6.
Control Head Type 8681 Maintenance, Troubleshooting Fault description Possible cause of the fault Troubleshooting Feedback signal is lost in system operation Position in the limit range of the feedback area Repeat the Teach-In process (see chapter 15.1. Setting the Position Measuring System (Teach-In)) Check the process valve end positions during operation against the end positions in non-operative state of the system. Check the compressed air supply.
Control Head Type 8681 ReplacementofComponentsandModules 19. Replacement of Components and Modules If components or modules need to be replaced for maintenance or service reasons, please observe the following notes and descriptions. Devices that are used in the explosion-risk area may be repaired by the manufacturer only. 19.1. Safety instructions DANGER! Risk of injury from high pressure! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 ReplacementofComponentsandModules 19.2. Changing the Electronics Module Note! Electrostatic sensitive components / modules! • The device contains electronic components, which react sensitively to electrostatic discharge (ESD). Contact with electrostatically charged persons or objects may be hazardous to these components. In the worst case scenario, they will be destroyed immediately or will fail after start-up.
Control Head Type 8681 ReplacementofComponentsandModules Installation procedure: →→Carefully insert the entire electronics module into the recess in the lower housing part. →→Plug the electronics module carefully onto the contact pins for the position measuring system. →→Refasten the electronics module with the Torx T10 screw (torque 0.4 Nm). →→Reattach the electrical connections.
Control Head Type 8681 ReplacementofComponentsandModules →→Loosen the electrical connections. →→Loosen the connecting screws (Torx T10) for the corresponding valve module. →→Take out the valve module and replace it with the spare part set.
Control Head Type 8681 ReplacementofComponentsandModules DANGER! Risk of injury from high pressure! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines. Note! Electrostatic sensitive components / modules! • Before changing the position measuring system, switch the electrical power for the control head off so that destruction of the PCB and electronics module is avoided.
Control Head Type 8681 ReplacementofComponentsandModules →→Loosen the electronics module's fastening screw (Torx 10) (see chapter 19.2. Changing the Electronics Module). →→Tilt the electronics forwards to loosen the position measuring system's contact pins from the electronics module. →→Bend the snap-fit hooks on the bottom end of the position measuring system inwards. In some cases, break them off. →→Pull the position measuring system upwards out of the guide.
Control Head Type 8681 Spare Parts 20. Spare Parts Caution! Risk of injury and/or damage by the use of incorrect parts! Incorrect accessories and unsuitable spare parts may cause injuries and damage the device and the surrounding area. • Use original accessories and original spare parts from Bürkert only. Item No. Spare Parts ID No. 1 O-ring 100 x 1.
Control Head Type 8681 Shutdown 21. Shutdown 21.1. Safety instructions DANGER! Risk of injury from high pressure! • Before loosening pneumatic lines and valves, turn off the pressure and vent the lines.
Control Head Type 8681 Packaging and Transport 22. Packaging and Transport Note! Transport damage! Inadequately protected equipment may be damaged during transport. • During transportation protect the device against moisture and dirt in shock-resistant packaging. • Avoid the effects of heat and cold which could result in temperatures above or below the permitted storage temperature.
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