Type 8741 Multi MFC Mass Flow Meter (MFM) / Mass Flow Controller (MFC) Massendurchflussmesser (MFM) / Massendurchflussregler (MFC) Débitmètre massique (MFM) / Régulateur de débit massique (MFC) Operating Instructions Bedienungsanleitung Manuel d‘utilisation
We reserve the right to make technical changes without notice. Technische Änderungen vorbehalten. Sous réserve de modifications techniques.
Type 8741 Table of content 1 User instructions...............................................................................5 1.1 Definition of the word "device"................................................ 5 1.2 Symbols used.............................................................................. 5 2 Intended use..............................................................................................6 2.1 Restrictions.......................................................................
12 Accessories /Spare Parts........................................................ 37 12.1 Electrical Accessories.............................................................37 12.2 Fluid accessories......................................................................37 12.3 Bürkert Communicator (PC software).................................38 12.4 Additional documentation.......................................................38 12.5 Spare parts..........................................................
Type 8741 User instructions 1 User instructions This manual describes the entire life cycle of the device. Please keep this manual in a safe place, accessible to all users and any new owners. Warning! Warns of a situation which is possibly dangerous! ▶▶ If ignored, serious injury or death may result. Important safety information! Please read the manual carefully. Pay particular attention to the sections entitled Basic safety information and Intended use.
Type 8741 Intended use 2 Intended use Improper use of the MFC/MFM may be a hazard to people, nearby equipment and the environment. MFM type 8741 is used exclusively to measure the mass flow of clean dry gases. MFC type 8741 is used exclusively to control the mass flow of clean dry gases. ▶▶ Observe the additional data, operating and service conditions specified in the contract documents, the manual and on the nameplate and calibration plate.
Type 8741 Basic safety information 3 Basic safety information These safety instructions do not take the following into account: • any contingencies or occurrences that may arise during installation, use and maintenance. • Location-specific safety regulations, adherence to which, also on the part of the mounting personnel, is the responsibility of the operator. Danger due to high pressure in the installation/device.
Type 8741 General information Note! Components / assemblies at risk from electrostatic charges! The device contains electronic components which are susceptible to electrostatic discharge (ESD). Contact with electrostatically charged persons or objects endangers these components. In the worst case, they will become defective immediately or will fail when energized. • To minimise or even avoid all damage due to an electrostatic discharge, take all the precautions described in the EN 613405-1.
Type 8741 System description 5 System description 5.1 Design of the MFM/MFC Connector* for electrical connection (4-pin screw terminals) LED to display the device status (in accordance with Namur 107) 5.2 General description Device Type 8741 is available in two basic versions. • As a Mass Flow Meter (MFM) the device measures the mass flow of the gases for which it has been calibrated.
Type 8741 System description Operation of the MFC (Mass Flow Controller) In order to obtain a dynamic or quiet measured-value output signal, the damping of this signal can be adjusted by the "Bürkert Communicator" software. See section "12.3 Bürkert Communicator (PC software)" Design: • The mass flow is measured by a sensor. • The MFC is fitted with electronics and a low-friction proportional valve with a high response sensitivity to control the mass flow.
Type 8741 System description 5.4.1 The MFC electronics The electronics • compare the measured value of the mass flow with the specified setpoint • and controls the opening of the proportional valve. Setpoint The setpoint (w) is transmitted digitally via the fieldbus interface. For control of a system where rapid flow-rate changes are not permitted, a ramp function can be activated. This enables the parameters for an ascending or descending setpoint to be set separately.
Type 8741 System description 5.4.2 MFC solenoid valve The solenoid valve used for an MFC is a direct-acting, normally-closed proportional valve. The nominal diameter of the solenoid valve is determined by the required nominal flow-rate Q nominal , the pressure conditions in the process and the density of the operating medium. Note! The sealing function of the proportional valve cannot be guaranteed for hard sealing materials.
Type 8741 Technical data 6 Technical data 6.1 Conformity Standards The standards used to demonstrate conformity with the Directives can be consulted in the EC type examination certificate and/or the EC declaration of conformity. 6.3 ax. 10 bar (depending on the nominal M diameter of the proportional valve) Warning! The Type 8741 complies with the EC-directives according to the EC declaration of conformity. 6.
Type 8741 Technical data 6.3.1 Quality of the operating medium 6.5 Fluid data For the required measurement and control precision and to meet the safety requirements, the gas or gas mixture must meet the following quality criteria according to standard ISO 8573-1 (Compressed Air Part 1: Contaminants and purity classes): Calibration medium: Operating gas or air Mass flow range ref. to N2 (IN/min): 0.01...
Type 8741 Technical data ∆p [mbar] 130 120 110 100 90 80 70 60 50 40 30 20 10 0 0 5 Fig. 3 : 6.6 Electrical data Operating voltage MFC: MFM: Max. Power consumption: MFM: ge n Fla 1/4'' 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Q [lN/min] Pressure loss diagram, for air, with a 250 µm input filter, for MFM type For other operating gases, the pressure drop pair can be read from the graph as a function of the flow rate Qair.
Type 8741 Technical data 6.7 Nameplate, calibration plate Nameplate description: Warning! Risk of injury caused by pressure, medium escape Important device-specific data are indicated on the nameplate and calibration plate. ▶▶ Only use the device for the specified operating medium. ▶▶ Do not exceed the specified calibration pressure. Calibration plate description Sealing material Max.
Type 8741 Installation 7 Installation 7.1 Safety instructions DANGER! Sequence of steps for installing the Type 8741: 1. Mechanical installation Note installation position! 2. Fluid system installation 3. Fieldbus setting Danger due to high pressure in the installation/device. ▶▶ Before working on the installation or device, cut the pressure and vent and drain the pipes. Risk of injury from electric shocks.
Type 8741 Installation 7.4 Fluid system installation →→Cut the pipe squarely [1] and deburr [2]. Danger! 1 Danger due to high pressure in the installation/device. ▶▶ Before working on the installation or device, cut the pressure and vent and drain the pipes. 2 Select the fluid connections according to the maximum mass flow rate. No inlet section is required. On request, the device can be supplied with the fluid connections fitted. Warning! Fig.
Type 8741 Installation →→Fix the sealing ring [C] and the connecting thread [B] to the device (tightening torque 25 - 28 Nm). nection is leak tight (tightening torque 25 - 28 Nm). B C Fig. 8 : →→Tighten the lock nut with an open-end spanner so that the con- Fix the sealing ring and screw on the connecting thread →→Insert the pipe and tighten the union nut [A] by hand. Fig. 10 : Tighten the union nut. Now make the fluid connection to the back of the device in the same way. A Fig.
Type 8741 Installation 7.5 Setting up the fieldbuses 7.6 büS or CANopen can be selected as the standard for the fieldbus. The fieldbus is preset at the factory. Changes to this setting should be performed before the electrical installation. The switch for setting the fieldbus is difficult to access after the electrical installation. There is a switch on the top of the device for setting the fieldbus. Electrical installation DANGER! Risk of injury from electric shocks.
Type 8741 Installation 7.6.1 Connect the power supply and communication cable Electrical input assignments: Screw terminals, 4-pin Pin Assignment 1 DGND 2 CAN_L 3 CAN_H 4 24 V Fig. 12 : Assignment; screw terminals, 4-pin 1 2 3 4 Cable assembly: (See "Fig. 13") →→Remove the insulation sheath over a length of approx. 25 mm. →→Shorten the cable shielding to the required length (see engraved symbols on the inside of the protective cover). →→Pull back the cable shielding over the insulation sheath.
Type 8741 Installation 7.7 Connecting the functional earth Warning! Connection of the cable screen to screw ME3: Note! Danger of ignition and fire due to electrostatic discharge! An electrostatic discharge of the device can ignite combustible gas vapours. ▶▶ The housing is connected via a short cable with a large cross-section to the functional earth (FE) to avoid a build up of electrostatic charge.
Type 8741 Commissioning 8 Commissioning 9 Operation and function 8.1 Safety instructions 9.1 Safety instructions Warning! Danger of injury from improper operation! Improper operation can lead to injuries and damage to the device and its environment. ▶▶ Before commissioning, it must be ensured that the operating personnel are familiar with, and fully understand, the content of this operating manual. ▶▶ The safety information and the intended use must be observed.
Type 8741 Operation and function The control parameters are set so that changes in the setpoint are effected as quickly as possible and without significant overshooting. The measured value for the mass flow-rate is made available via the fieldbus communication interface. 9.3 Display in accordance with NE 107 Description Meaning Colour Yellow Outside specification Ambient or process conditions for the device are outside the permissible ranges. Datasheet values cannot be complied with.
Type 8741 Operation and function Display in accordance with NE 107 Description Status Flashing* Identification: Device connected to the network* Meaning Identifies a device on the büS network. "Flashing" status is started when the device is selected in the "Bürkert Communicator" software. * For a detailed description of the fieldbus protocols for type 8741, see supplementary manual entitled "Digital Communication Type 8741". 9.
Type 8741 Operation and function 9.5 Removable data memory The MFC/MFM has a removable data memory the size of a micro SIM card, on which the device-specific data is stored. The device is delivered with the micro SIM card inserted. The micro SIM card enables the exchange of specific data with devices having the same ID number. For example, to transfer the data from a faulty unit to a new device. 9.5.1 Exchanging the micro SIM card →→Slide the micro SIM card into the device as shown in "Fig. 18".
Type 8741 Operation and function 9.6 Functions 9.6.1 AUTOTUNE function Function optimisation of the MFC control parameters. For the MFC, the AUTOTUNE function is conducted at the factory. This is done at the operating pressure and with the calibration medium specified in the calibration protocol. A re-run of this function is not normally necessary. However, a re-run of the AUTOTUNE function is required in the following cases: • If the pressure conditions in the installation have changed.
Type 8741 Operation and function 9.6.2 In the büS network, other peers process the process values. The procedure for specifying the SETPOINT SOURCE is described in the supplementary operating instructions "Digital Communication, Type 8741". The MFM/MFC can receive and process the process values from other büS peers in a büS network. AUTOMATIC function: For example, another bus peer can provide the MFC with a setpoint or the MFC/MFM can send its process values to other büS peers.
Type 8741 Operation and function OPEN LOOP CONTROL function: 9.6.5 This function allows the duty cycle to the proportional valve to be specified directly. When this function is activated the current duty cycle is used. The cyclic data can be updated from the device with a specific inhibit time. The inhibit time determines the time span in which a process value is updated. Following a restart of the device, the cycle is set to zero.
Type 8741 Maintenance 10 Maintenance The MFM/MFC is maintenance-free, provided that no heavily contaminated media are used and that it is operated according to the instructions in this manual. 10.1 Maintenance for operation with heavily contaminated media DANGER! Danger due to high pressure in the installation/device. ▶▶ Before working on the installation or device, cut the pressure and vent and drain the pipes. Risk of injury from electric shocks.
Type 8741 Maintenance 10.1.1 Cleaning the stainless steel mesh filter →→Clean the stainless steel mesh filter [5]. Do not clean with tap water! Clean with acetone, isopropanol or compressed air. →→Dry the stainless steel mesh filter after cleaning. →→Install the parts in the correct order (see "Fig. 19"). 1 2 3 4 The fine side of the stainless steel mesh filter [5] must face the inlet flange plate [2].
Type 8741 Device status/Troubleshooting 11 Device status/Troubleshooting 11.1 Display of the device status The MFM/MFC has an LED to display the device status, the colour and status change according to NAMUR 107. If more than one device status exists simultaneously, the device status with the highest priority is displayed. LED acc. to NE 107 OFF Description The device is not energized. What to do? Energize the device. Flashing Device is selected using the "Bürkert Communicator" software.
Type 8741 Device status/Troubleshooting LED acc. to NE 107 Description What to do? Red / Lit Mode 4: communication with other büS peers is impossible. Mode 5: Supply voltage is 20% under or above the nominal value. Mode 1: Bus error (e.g. short-circuit). Connect the device in a network with other peers. Red / Flashing Check the power supply. Check the wiring. Exception: SETPOINT SOURCE set to STORED SETPOINT. Mode 2: Supply voltage is 20% under or above the nominal value.
Type 8741 Device status/Troubleshooting LED acc. to NE 107 Description What to do? Orange / Flashing Mode 1: calibration activated. - Mode 2: Increase the operating pressure (observe the maximum permissible The control variable for the proportional valve has (almost) supply pressure). reached 100%. The setpoint cannot be reached. Check the pressure drop in the pipe and reduce it if necessary. Check the dimensions of the installation. Check the filters installed in the pipe and clean them if necessary.
Type 8741 Device status/Troubleshooting 11.2 Troubleshooting Problem The Namur LED goes out periodically Possible cause The power supply is intermittently dropping - the device therefore performs a reset. The voltage drop in the connecting cable is too large. The exchange device adopts none of the values on the micro SIM card from the faulty device The ID number of the exchange device differs from that of the defective device.
Type 8741 Device status/Troubleshooting Problem Unstable measured value Setpoint at 0 % but operating medium still flows Setpoint value at 0 %, valve is closed, no mass flow, but a non-zero mass flow rate is measured Setpoint value is not reached Possible cause The functional earth (FE) is not properly connected. The controller must compensate for irregularities in an unstable pressure supply caused, for example, by pumps. The residual ripple on the voltage supply is too high.
Type 8741 Accessories /Spare Parts 12 Accessories /Spare Parts 12.2 Fluid accessories The MFM / MFC is equipped with a threaded process connection plate according to DIN ISO 228/1. Caution! Danger of injury and material damage due to unsuitable parts! A threaded fitting, available as an accessory, is used to connect the device to a pipe: Incorrect accessories and unsuitable replacement parts can cause injuries and damage to the device and its environment.
Type 8741 Accessories /Spare Parts 12.3 The seal for each threaded connection must be ordered separately. 12.4 Each order code includes one piece. • Supplementary operating instructions "Digital Communication" on the description of the fieldbus protocol for the Type 8741 (download from www.burkert.com). Bürkert Communicator (PC software) The "Bürkert Communicator" PC software enables communication with the type 8741. "Bürkert Communicator" software runs under Windows.
Type 8741 Dismantling 13 Dismantling 13.1 Safety instructions Procedure: A B Danger! Danger due to high pressure in the installation/device. ▶▶ Before working on the installation or device, cut the pressure and vent and drain the pipes. Risk of injury from electric shocks. ▶▶ Before working on the installation or device, switch off the power and ensure that it cannot be reactivated. ▶▶ Observe the applicable accident protection and safety regulations for electrical equipment.
Type 8741 Transport, storage, disposal 14 Transport, storage, disposal Note! Transport damage! Damage can be caused to insufficiently protected devices in transport. • Remove cables, connectors, separate filters and mounting hardware. • Clean and vent contaminated devices. • Close the fluid connections with protective caps to prevent damage and protect the sealing. • Pack the device in two suitable zip lock bags. • Transport the device in an impact-resistant package, protected from moisture and dirt.
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