Subscribe to Our Youtube Channel
Related Manuals for Megger MV DAC-30
Summary of Contents for Megger MV DAC-30
- Page 1 MV DAC-30 Partial discharge measuring system USER GUIDE Issue: C (04/2022) - EN Article number: 84563...
- Page 3 The information in this document is subject to change without notice and should not be construed as a commitment by Megger. Megger cannot be made liable for technical or printing errors or shortcomings of this handbook. Megger also disclaims all responsibility for damage resulting...
- Page 4 Each component and product replaced in accordance with this warranty becomes the property of Megger. All warranty claims versus Megger are hereby limited to a period of 12 months from the date of delivery. Each component supplied by Megger within the context of warranty will also be covered by this warranty for the remaining period of time but for 90 days at least.
- Page 5 Contents Contents Consultation with Megger ....................3 Terms of Warranty ......................4 Contents ........................... 5 Safety Instructions ................... 7 General Notes ....................7 General Safety Instructions and Warnings ............8 Technical Description ..................9 Abbreviations ...................... 9 System Description .................... 9 Technical Data ....................
- Page 6 Contents Configuring Settings and Managing Data............ 55 Adjusting the Settings – ................55 7.1.1 Managing Devices .................... 57 7.1.2 Managing Report Templates ................58 Cable Manager – ................... 62 7.2.1 Viewing Cable Data and Administrating Measurement Tasks ......62 7.2.2 Managing Cables .....................
- Page 7 It is important to observe the generally applicable electrical regulations of the country in Working with products which the device will be installed and operated, as well as the current national accident from Megger prevention regulations and internal company directives (work, operating and safety regulations).
- Page 8 If, contrary to the regulations, any other extinguishing agent is • used for fire fighting, this may lead to damage at the electrical installation. Megger disclaims any liability for consequential damage. Furthermore, when using a powder extinguisher near high-voltage installations, there is a danger that the operator of the fire extinguisher will get an electrical shock from a voltage arc-over (due to the powder dust created).
- Page 9 Voltage Withstand Diagnosis Ankoppelvierpol (Quadripole) System Description The MV DAC-30 is a partial discharge measurement system that allows for the Functional description identification, classification and location of PD faults in the insulation and the accessories of all kinds of medium voltage cables. It consists of a HV source, a thyristor switch, a...
- Page 10 Technical Description The DAC voltage allows a cable-friendly PD diagnosis in conformity with IEC 60270. One major benefit of this voltage waveform is the similarity between the DAC slope and the 50 Hz power frequency (“50 Hz Slope Technology”) which can be clearly seen in the following figure: This is particularly important for PD diagnosis, since reliable evaluation of the measured results requires a direct comparability with the power frequency.
- Page 11 Technical Description Scope of delivery The scope of delivery includes the following: Component Description Article number Partial discharge measurement system MV DAC-30 Notebook With preinstalled software and language- case dependent Software license 3 dongles included 90011937 PD calibrator CAL1 Conformity:...
- Page 12 Technical Description Technical Data The partial discharge measurement system MV DAC-30 and the included PD detector are Technical Data specified by the following parameters: Parameter Value Voltage range 3 … 30 kV DC DAC frequency 20 Hz … 500 Hz Testable load capacitance 1 nF …...
- Page 13 Technical Description The following diagram illustrates the dependency of the maximum testable load capacity Load diagram on the test voltage.
- Page 14 Technical Description Modules, Connections and Control Elements The system consists of the following two modules and offers the following control and connection elements: Element Description “HV On” button EMERGENCY OFF switch ON/OFF button HV interlock key switch Control module HV module “HV Off”...
- Page 15 Technical Description The optional external safety device has the following controls and indicators: External safety device Part Description Green signal light Lights up when the system is switched on but is not in high voltage operation. “HV interlock” key switch High voltage unlocked High voltage locked In the locked state, the key can be removed and the system can thus be...
- Page 16 Technical Background To be informed about the condition and residual life of their resources is increasingly What is Partial important for network operators in order to be able to plan and optimise the investment Discharge and why test and maintenance measures. for it? By the use of condition-based maintenance of medium voltage cable networks with the help of cable diagnosis and cable tests, it is possible to considerably reduce the costs for...
- Page 17 How can PD be In order to measure partial discharges, the test object is applied with the required voltage. The generated high-frequency PD signals are decoupled by means of a special AKV. measured and located? By gradually raising the voltage it is possible to detect at which voltage the PD ignites (PDIV) and how the PD level changes with increasing voltage.
- Page 18 Commissioning Commissioning General safety instructions for set-up and commissioning The safety guidelines for the operation of mobile testing systems • often differ from one network operator to another and are frequently subject to national regulations (such as the German BGI 5191). WARNING Before the measurement session, find out what the applicable guidelines are and follow the rules set out therein precisely, in...
- Page 19 Commissioning The following picture shows the simplified connection diagram: Connection diagram 230 V, 50/60 Hz Station earth or other suitable foundation earth electrode Prohibition zone and test area acc. to DIN EN 50191 (VDE 0104) Procedure Please perform the following steps for the electrical connection: Step Action Roll the HV module to the desired installation site and apply all four wheel...
- Page 20 Connect a notebook with latest version of the measurement software to the network jack of the MV DAC-30 source by means of the supplied network cable. Connect the power cord included in the scope of the delivery to the system’s power socket and a power supply socket.
- Page 21 Commissioning Switching On Please perform the following steps in order to get everything ready for the measurement: Step Action Switch on the test voltage source via the white ON/OFF button Switch on the notebook. Plug the supplied dongle into a USB port of the notebook. Start the measurement software by double-clicking the desktop icon.
- Page 22 Basic Operation of the Software Basic Operation of the Software Start Screen After the PD measurement software has been opened, the main menu appears which enables the user to call up the individual modules of the software: Main menu of the PC software Main menu of the test van software The following modules are available: Module Description...
- Page 23 Basic Operation of the Software Useful Features of the Software In order to make the search in extensive lists (e.g. cable lists) easier there is always a Search and sort search form near the list in which any character string can be entered. While entering, the functions list is immediately filtered by entries that contain this character string.
- Page 24 Basic Operation of the Software Administration of To guarantee quick access to frequently used cable templates, these can be added to the favourites favourites ( ) list by clicking on the symbol, or be removed from the list ( ) by clicking again.
- Page 25 Select the cable end at which the current measurement is conducted under Measured at. If required, select Megger MV DAC from the HV source drop down list. The drop down list is only available if more than one HV source is configured in the software.
- Page 26 Conducting Measurements Step Action Click on Apply in order to confirm the selection. Before starting a new measurement task, ensure that the measurement data recording has been completed for the measurement task currently in progress! Result: The software jumps back to the start screen. The measurement task is initialised, and the cable allocated to the measurement task is displayed on top of the selection menu.
- Page 27 Conducting Measurements Calibrating the Partial Discharge Measuring Circuit – In order to be able to conduct a calibration, a new measurement task must have been Prerequisites started beforehand (see page 25). Otherwise the menu point in the start screen is greyed out.
- Page 28 Conducting Measurements Step Action Cancel the earthing and short circuiting measures on both ends of the cable that is to be tested. Since the supplied calibrator automatically switches off approx. 10 minutes after the last operational action, the actual calibration should be conducted directly after connecting the calibrator.
- Page 29 Conducting Measurements Step Action Adjust the calibration settings. The value in the input field Length has been adopted automatically from the cable data and normally does not have to be corrected. Should the length value be uncertain and the exact pulse propagation velocity be known, then the velocity needs to be provided instead.
- Page 30 Conducting Measurements The quality of the subsequent measurement results depends on various factors, Checking the markers particularly the accuracy of calibration. It is therefore advisable to check the automatic positioning of the markers and correct them if necessary before applying the calibration data.
- Page 31 Conducting Measurements In the charge diagram, the line should mark roughly the average value of the periodically measured calibration pulses. If a correction has to be made, the respective mark has to be clicked once with the left mouse button. As a result, the line width of the marker increases and the mouse pointer changes into the symbol.
- Page 32 Conducting Measurements Measuring – In order to conduct the measurement, a new measurement task must have been started Prerequisites (see page 25) beforehand and the partial discharge measuring circuit must have been calibrated (see page 27). Otherwise the menu point is greyed out in the start screen.
- Page 33 Conducting Measurements 5.3.2 Available diagram types The measurement screen provides access to various diagrams during the measurement. Introduction In the upper part of the screen, PD mapping with the previously recorded PD events is displayed by default. The diagram type directly below can be changed using the tabs at the bottom.
- Page 34 Conducting Measurements Using the Advanced menu item, you can display the advanced view filters and the pulses in the PD mapping can be filtered as you wish to provide a better overview: The following buttons are available for this purpose: Button Description Filter view according to phase.
- Page 35 Conducting Measurements In order to enlarge a certain area of the PD mapping, simply draw a frame around the area while holding the mouse button. Clicking removes the magnification. The Q(t)/U(t) view displays the temporal profile of the measured charge level (the partial Q(t)/U(t) discharge pattern) and the excitation voltage.
- Page 36 Conducting Measurements With the scrollbar, depending on the voltage waveform, you can switch back and forth between the recorded measurement windows (the individual shots for DAC, the polarity reversals for VLF-CR or the triggered PD pulses for VLF-SIN). The checkbox Switch to this view on any new event can be used to determine whether the software automatically switches to the localisation diagram with each recorded PD event.
- Page 37 Conducting Measurements 5.3.3 Setting the Measurement Parameters The configuration of the PD detector must be performed through the menu block specially Configuring the PD provided for this purpose: detector PD Detector Phase Q Range State Stopped The following settings are possible: Parameter Description Phase...
- Page 38 Conducting Measurements The configuration of the test voltage source must be performed through the menu block Configuring the test specially provided for this purpose: voltage source Mode DAC- 5 shots 30 kV peak max kV peak kV rms x Uo Voltage 17,3 peak...
- Page 39 Conducting Measurements 5.3.4 Performing the Measurement Directly from entering the measurement screen, the connection with all devices involved Starting the measurement in the measurement is permanently checked. Deactivated buttons and the symbol indicate connection problems, which have to be solved before the test is started (see page 81).
- Page 40 Conducting Measurements The saving of test data is initiated exclusively with the buttons of the menu block specially Saving test data provided for this purpose. By default, each completed individual measurement must be saved manually. Otherwise, the data are discarded when the next individual measurement is started! Certain defined parameters, such as PDIV and PDEV, are to be saved using specially dedicated buttons.
- Page 41 Conducting Measurements Button Description Save PDIV This button must be clicked if, during the previous measurement, initially critical PD of a defined strength were detected (PD inception). The voltage set prior to starting the measurement is saved as PDIV. Set PDEV This button for saving the PDEV should be clicked, if both the inception and the extinction of the PD can be clearly distinguished from the PD pattern of the previous measurement.
- Page 42 Conducting Measurements 5.3.4.1 Typical Procedure for PD Diagnosis The following described procedure is a recommended, but by no means binding approach Procedure to PD diagnosis and can deviate from parts of the applicable company-internal guidelines or country-specific standards: Step Action Start the Disturbance level measurement to determine the disturbance level of the PD measuring circuit and save the result with the Save Disturbance level button.
- Page 43 Conducting Measurements 5.3.4.2 Typical Procedure for Monitored Withstand Testing Proceed as follows to perform a withstand test: Step Action Start the Disturbance level measurement to determine the disturbance level of the PD measuring circuit and save the result with the Save Disturbance level button.
- Page 44 Conducting Measurements 5.3.5 Stopping / Finishing a Measurement Each measurement is always ended automatically after the specified test cycles have run. Stopping a In this case, the system lingers in the operating state of “Ready for switching on” after the measurement measurement, which is indicated by the red illuminated “HV-OFF”...
- Page 45 Evaluating Measurement Results and Creating a Report Evaluating Measurement Results and Creating a Report If the evaluation of the measurement results will be performed directly after the Opening the evaluation screen measurement, you can directly call up the menu item in the start screen.
- Page 46 Evaluating Measurement Results and Creating a Report Based on the time difference between the arrival of the actual pulse and its reflection from the cable end, the remaining pulse can then be correlated (see page 17) with a concrete position along the cable to a very high degree of accuracy. The now spatially resolved imaging is examined for localised clusters of PD events and colour-coded as follows: Colour Description...
- Page 47 Evaluating Measurement Results and Creating a Report Using the Advanced menu item, you can display the advanced view filters and the pulses View filter in the PD mapping can be filtered as you wish to provide a better overview: For this, the following buttons are available: Button Description Filter view according to phase.
- Page 48 Evaluating Measurement Results and Creating a Report Manual Evaluation of Partial Discharges Generally, the automatic detection and location of partial discharges by the PD evaluation Necessity algorithm is very accurate. In most cases, a time-consuming post-processing of the measurement data is not needed and the report can be directly created (see page 52). However, if there are reasonable doubts as to the position or “realness”...
- Page 49 Evaluating Measurement Results and Creating a Report 6.1.2 Analysing Individual PD Events Each measured and automatically (via the software) classified pulse can be manually Selecting a PD event evaluated by the user and given a different classification, if necessary. In order to carry out a manual evaluation, the pulse must first be selected with a left mouse click.
- Page 50 Evaluating Measurement Results and Creating a Report Directly after a PD event has been selected, it can be analysed more precisely using the Manual analysis diagrams available under the PD mapping and can be classified differently if necessary. The Localisation tab can for example be used to call up the TDR image, which shows both the directly incoming pulse and its reflection at the far end of the cable.
- Page 51 Evaluating Measurement Results and Creating a Report If a more detailed analysis of PD events reveals doubts about the automatically performed Manual classification classification and it needs to be corrected manually, an additional toolbar can be displayed using the Manual Analysis button. Using the buttons in the toolbar, the events can be classified manually or even deleted.
- Page 52 Evaluating Measurement Results and Creating a Report Preparing and Printing the Report The risk assessment for reliable network operation must be performed taking into account Risk assessment / the respective isolating systems, the type of faults as well as the measured PD. recommendation A recommendation on how to proceed based on the risk assessment can be entered in the text field available through the Recommendation tab.
- Page 53 Evaluating Measurement Results and Creating a Report Even though any meaningful VWD diagram could have already been selected for inclusion in the report during the actual measurement, by saving the respective measurements using the Save VWD button, diagrams can still be added and removed during report creation.
- Page 54 PDF viewer, where it can be saved or printed on the selected printer (see page 55). If a full version of the Megger Book Cable protocol software is installed on the same computer, the generated PDF report is automatically added to the list of previous measurement activities on the selected cable.
- Page 55 Configuring Settings and Managing Data Configuring Settings and Managing Data Adjusting the Settings – The following software settings can be adjusted: Category Description General Language Selection of menu language Default printer Printer that should print the created PDF reports Show Clock These parameters can be used to specify whether and in what format the clock and date should be Show Am/PM...
- Page 56 Configuring Settings and Managing Data Category Description Localisation Polarity check With the polarity check active, only those pulses for which the original pulse and the reflection have the same polarity are considered as possible partial discharge pulses. This procedure complies with the requirements of the normal partial discharge measurement, which is why the polarity check should not normally be disabled!
- Page 57 Configuring Settings and Managing Data 7.1.1 Managing Devices Under Devices, all devices configured in the software are listed. If one of the devices is Introduction selected, its settings are shown in the right section of the screen. In general, these settings (in particular the network and connection settings) should only be changed at the request of a service employee.
- Page 58 Configuring Settings and Managing Data 7.1.2 Managing Report Templates In the Report section the content of the diagnostic report can be freely modified to your Introduction needs and any number of templates can be created. When the software is delivered, a template that satisfies the typical requirements for a diagnostics report is already included.
- Page 59 Configuring Settings and Managing Data Proceed as follows to modify the content of a template: Modifying the content of a template Step Action Using the pull-down menu, select the template that you want to modify. Customise the content that a report based on this template should include based on your needs (see below).
- Page 60 Configuring Settings and Managing Data Category Content PD Mapping List of the PD mappings to be included in the report. The checkboxes in the first line can be used to specify which information is to be displayed in each of the PD mappings contained in the report (cable plan, histogram, important positions, non- relevant PD events and non-localized PD events).
- Page 61 Configuring Settings and Managing Data Category Content PRPD PRPD diagrams of the individual phases. Localization The TDR diagrams which have been selected during the Diagrams preparation of the report (see page 52). VWD Plots The VWD diagrams which have been selected during the preparation of the report (see page 52).
- Page 62 Configuring Settings and Managing Data Cable Manager – The cable manager serves for maintaining the cable data. These are stored in a local Introduction database, which is also used by the MeggerBook Cable protocol software (if also installed on the computer). This ensures that the cable data is consistent across all applications installed on the machine, i.e.
- Page 63 Configuring Settings and Managing Data Under the Sections tab, detailed information on the individual cable segments can be Cable sections viewed: The Measurement tasks tab provides a list of all measurements conducted on this cable Measurement tasks system. An Active measurement task is marked in bold.
- Page 64 Configuring Settings and Managing Data After an item of this list has been selected, the following functions can be called up: Button Description Load The measurement data of the selected measurement task are loaded into the memory. After a previous measurement task has been loaded, the menu point can be called up via the start screen and the measurement data can be once again evaluated (see page 45).
- Page 65 Configuring Settings and Managing Data 7.2.2 Managing Cables With the help of the buttons of the Edit menu block, existing cables can be managed and Functions new cables can be created. The following functions are available: Button Description Create a new cable (see next section). Edit Edit the cable that is currently selected in the cable list (see next sections).
- Page 66 Configuring Settings and Managing Data The following entry forms allow entering the cable parameters: Entry form Description Cable number Number / designation of the cable system The cable number has to be unique and must not be used twice! Uo [kV rms] Nominal voltage Uo of the cable (in kV Location Location of the cable...
- Page 67 Configuring Settings and Managing Data 7.2.2.2 Specifying the Sections of the Cable Via the tab Sections you get to the second entry form in which all cable types and joints Introduction of all cable sections have to be specified. In case of homogeneous cable systems without joints exactly one section with the total General notes cable length needs to be specified.
- Page 68 Configuring Settings and Managing Data By means of three buttons placed above the list, cable sections can be added and edited Adding / Editing a according to the following scheme: section Insert Edit After pressing one of these buttons, a new window for entering/editing the section data opens.
- Page 69 Configuring Settings and Managing Data Parameter Description Length [m] The length of the cable section in metres. When adding a new cable section before the marked section, an additional tickbox is made available in this line. If this box is ticked, the length of the new section is subtracted from the length of the marked section (which is equivalent to cutting the marked section).
- Page 70 Configuring Settings and Managing Data If a cable was cut and a joint inserted during maintenance work, this change can also be Cutting a section made to the digital image of the cable with just a few clicks using the cutting tool. To do this, proceed as follows: Step Action Select the cable section to be cut from the list or directly in the cable plan.
- Page 71 Configuring Settings and Managing Data 7.2.2.3 Saving Cable Data After the cable data have been entered as completely as possible, the new or edited cable can be saved via the button Apply at the right bottom side of the screen. With the button Cancel the entry form will be closed without saving and all performed changes are discarded.
- Page 72 Configuring Settings and Managing Data 7.2.2.4 Managing Segment Templates To be able to specify the cable and joint types in a cable section explicitly, the Introduction corresponding templates must be filed in the database. A number of typical datasets are already stored in the database upon delivery.
- Page 73 Configuring Settings and Managing Data A new joint template can be created, and the joint template currently selected can be Creating/editing a joint template edited, using the buttons. After clicking the button, a new window opens in which the following properties can be defined for the template: Parameter Description Description...
- Page 74 Configuring Settings and Managing Data 7.2.3 Managing Measuring and Cable Data With the aid of the import and export assistants, measuring and cable data can be Introduction exchanged between the databases of various TE detector software installations. There is also the possibility of importing the following non-system data: Measuring and cable data from a OWTS PD diagnostic system (optional •...
- Page 75 Configuring Settings and Managing Data 7.2.3.1 Exporting Data Proceed as follows in order to export cable and measuring data from the local database to a data carrier of your choice: Step Action Click on Export in the Edit menu block. Result: The export assistant is opened in a new window.
- Page 76 Configuring Settings and Managing Data 7.2.3.2 Importing Data Proceed as follows to prepare the import of cable and measuring data: 1. Step: Applying the import Step Action settings Click on the Import in the Edit menu block. Result: The import assistant is opened in a new window. Select the data format to be imported from the following options: PD Detector data Measuring and cable data from another TE detector...
- Page 77 Configuring Settings and Managing Data 2. Step: If the import of cable data is activated in the import settings, an overview of the identified cables appears. If required, the basic cable data can be adapted and cables can also be Selecting the cables completely excluded from the import.
- Page 78 To prevent loss of data (e.g. in the event of a hard drive defect), it is recommended to regularly perform a backup of the measuring and cable data. The following data must be saved: Cable data: File %installation folder%\Megger.mcb Measuring data: Directory %installation folder%\data\ A suitable backup strategy should be developed by the responsible system administrator.
- Page 79 The MV DAC-30 is a highly sensitive measuring system which should always be moved Transport with great care! Safe transport of the system can only be ensured if its components are...
- Page 80 If the fuses are defective, they must be replaced with suitable microfuses (5 x 20 mm) of the type T2.5A (230 V version) or T5A (115 V version). If the fuses continue to trip, please get in touch with the Megger service department in order to have the problem resolved.
- Page 81 Troubleshooting Troubleshooting If problems occur, these can - under certain circumstances - be diagnosed and solved Independent using the following table: troubleshooting Problem / Error message Cause / Remedy Connection to test voltage Restart the affected device • source or PD detector cannot Restart notebook and measurement software •...
- Page 82 In malfunction this case inform the person in charge who should inform the Megger service to resolve the problem. The instrument may only be operated when the malfunction is resolved.
- Page 83 Tento symbol indikuje, že výrobek nesoucí takovéto označení nelze likvidovat společně s běžným domovním odpadem. Jelikož se jedná o produkt obchodovaný mezi podnikatelskými subjekty (B2B), nelze jej likvidovat ani ve veřejných sběrných dvorech. Pokud se potřebujete tohoto výrobku zbavit, obraťte se na organizaci specializující se na likvidaci starých elektrických spotřebičů...
Need help?
Do you have a question about the MV DAC-30 and is the answer not in the manual?
Questions and answers