Related Manuals for Megger MFM 10
Summary of Contents for Megger MFM 10
- Page 1 MFM 10 Sheath Fault Location System USER GUIDE Issue: C (8/2023) - EN Article number: 128311783...
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Page 3: Consultation With Megger
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: Terms Of Warranty
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: Table Of Contents
Contents Contents Consultation with Megger ....................3 Terms of Warranty ......................4 Contents ........................... 5 Safety Instructions ................... 7 Basic Notes ......................7 General Safety Instructions and Warnings ............8 Technical Description ..................10 System Description ..................10 Technical Data ....................12 Connections, Controls and Display .............. -
Page 7: Safety Instructions
This handbook contains basic instructions for the commissioning and operation of the Safety precautions MFM 10. For this reason, it is important to ensure that the manual is always available to authorised and trained personnel. Operating personnel should read the manual thoroughly. -
Page 8: General Safety Instructions And Warnings
The MFM 10 is built to be robust and can withstand the stresses it can expect to be subjected to in demanding everyday use. Nevertheless, it is a precision measuring device which needs to be treated with the appropriate care. - Page 9 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).
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Page 10: Technical Description
Accordingly, the MFM 10 permits in the easiest way the testing of cable sheaths and prelocation and pinpointing of cable sheath faults. To detect sheath faults, the MFM 10 works in test mode with a voltage of up to 10 kV Function (negative polarity), which also permits cables with a thicker outer sheath to be tested. - Page 11 Technical Description Features The MFM 10 combines the following features in a single device: • Easy and comfortable operation via rotary encoder (EasyGo) and touch screen Bipolar measurement • Prelocation by means of the voltage drop method with a direct measurement of •...
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Page 12: Technical Data
Technical Description Optional accessories The following optional accessories can also be ordered from Megger Sales: Accessory Description Item number Connection set for HV Connection set with 8 larger connection 118308004 cable terminations clamps (e.g. for HV cable terminations) and connection cables 2 m in length (for the... -
Page 13: Operating Humidity
Technical Description Parameter Value Display 320 x 240 pixel LCD, LED backlight Interfaces USB port Memory 2 GB flash memory for system and user data Data logging with a USB stick Operating temperature −25 °C ... +55 °C Storage temperature −40 °C ... -
Page 14: Connections, Controls And Display
“HV OFF” push-button Rotary encoder Protective earthing connection HV output The MFM 10 generates a dangerous voltage of up to 10 kV during HV operation. This is induced into the HV connection cable through the HV output. WARNING Power supply socket with fuses F1 / F2 (2 x M6.3/250) 12 …... -
Page 15: Commissioning
• suitable earthing point (e.g. station earth). Inadequate protective earth, especially when operating the MFM 10 by battery, can raise the potential of the device, and the hazardous voltages produced make it unsafe to handle. -
Page 16: Electrical Connection: Typical Procedure
Step Description Using the earthing cable, the protective earthing connection of the MFM 10 is connected to a suitable point on the protective earth system (station earth). Plug in and tighten the HV connection cable to the HV output on the device, in compliance with the alignment specified by the guide grooves. - Page 17 If the unit is to be powered through the mains, connect the supplied mains power cable to the power supply socket of the MFM 10 and a mains socket. Otherwise, the device on being switched on is automatically powered by the internal battery.
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Page 18: Electrical Connection: Special Applications
Commissioning Electrical Connection: Special Applications If the MFM 10 is only to be used in testing, burning or pinpointing mode, an auxiliary Simplified connection methods conductor is not necessarily needed. Accordingly, in these operating modes, the wiring at the far cable end can be omitted while all connecting leads except of the yellow one have... - Page 19 Commissioning This method of prelocating a fault should only be used when absolutely unavoidable, e.g. Prelocation using one when no second, fault-free auxiliary conductor is available. auxiliary conductor only The precision will be impaired in the same way as the simple Murray loop bridge is impaired by the effects of the contact resistances, but should remain comparatively higher.
- Page 20 Commissioning Using the MFM 10, it is possible to locate non-earthed faults in inner conductors. In MV Prelocation of non- cables with standard cross sections in particular, faults with a fault resistance of several earthed inner MΩ can be prelocated to within a few metres.
- Page 21 Commissioning Prelocation when there Under certain circumstances, prelocation can also be performed on a spooled cable which allows the MFM 10 to be connected directly to both ends of the cables. is direct access to both ends of the cable...
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Page 22: Use Of An External Safety Device (Optional)
Commissioning Use of an External Safety Device (Optional) Purpose With the aid of an external safety device, the current status of the system can be made clearly visible with coloured signal lamps and the generation of HV can be interrupted or locked with an EMERGENCY OFF switch and key switch (norm-compliant signalling and EMERGENCY OFF according to DIN EN 50191 / VDE 0104). -
Page 23: Operation
A corresponding message appears on the display. The MFM 10 is started by pressing the on/off push-button . After a few seconds, the system is ready for use. The main menu appears in the display. - Page 24 Operation Status bar The status bar at the bottom of the screen provides the following information: System Power supply status information … Mains operation (tap to view) … Battery operation Firmware Date / Time Remaining version battery capacity When setting a variable parameter, the following view appears: Adjusting the test or measuring parameters The value of the parameter can then be varied by turning the rotary encoder within the...
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Page 25: Security Mechanisms
Operation Security Mechanisms The safety circuit of the system permanently tests all security-related parameters and Introduction switching operations on the system as soon as an operating mode is selected that activates the HV output. Should the safety circuit detect a deviation from the monitored conditions while in high voltage mode, high voltage is immediately switched off and the HV output is discharged. -
Page 26: System Settings
Operation System Settings The setup menu which is divided into following categories can be accessed via the menu item from the main menu: Category Setting Description General Date / Time Correct date and time settings are required for the logging function. Sprache Selection of the interface language. -
Page 27: Operating Modes
5 to 10 minutes depending on the cable type. A test of the inner insulation of a PILC cable should last between 25 and 30 minutes. At a setting of 0 minutes, the MFM 10 runs in continuous operation mode and must be stopped manually. - Page 28 Operation Proceed as follows to perform insulation testing: Procedure Step Description In the main menu, call up the menu item Set voltage and test duration in accordance with the type of cable to be tested (see previous page). Start the test via the menu item Press the “HV ON”...
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Page 29: Prelocating A Fault
If, for example, a cable consists of 6 sections and the fault is located in section 3, only the data for section 1, 2 and 3 need to be entered before the MFM 10 provides the correct fault distance. - Page 30 Operation Proceed as follows to perform fault prelocation: Procedure Step Description In the main menu, call up the menu item Set the voltage, the cable length and the type of cable (see previous page). Start the fault location via the menu item Press the “HV ON”...
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Page 31: Pinpointing A Sheath Fault
4.5.3 Pinpointing a Sheath Fault - During sheath fault pinpointing, the MFM 10 transmits direct current pulses at an Introduction adjustable rate into the shield affected by the earth fault. With each coupled pulse, the current flowing into the ground forms voltage gradients in the area around the fault, the centre of which can be located precisely with the assistance of a sheath fault locator and its earth rods (step voltage method). - Page 32 Start the pinpointing via the menu item Press the “HV ON” push-button Result: The MFM 10 with the set pulsing couples the DC pulse in the shield affected by the earth fault. Locate the fault location with the assistance of a suitable receiver (e.g. ESG, A-frame).
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Page 33: Burning
Operation 4.5.4 Burning - The available current of up to 750 mA also enables a fault conversion by the so-called Introduction “burning” of difficult sheath faults (e.g. high-impedance or intermittent faults). In which the thermal reaction to the electric arc converts the hydrocarbons of the cable insulation at the fault location into conductive carbon. - Page 34 Operation Step Description Terminate the burning process by pressing the “HV OFF” push-button The burning process will stop automatically after 5 minutes, if by this time it hasn’t been stopped manually. Between two time-consuming burning operations the unit needs to cool down for a few minutes! CAUTION Afterwards, try to prelocate (see page 29) the sheath fault again.
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Page 35: Concluding The Test
The test object is to be earthed and short-circuited as well as checked that it has been completely discharged (e.g. using a properly sized discharge rod). Afterwards, the MFM 10 can be disconnected from the test object. Follow the five safety rules (see page 8). -
Page 36: Processing Log Data
Processing Log Data Processing Log Data When log data are exported after a test is complete, the files are written to the \Prot directory on the USB flash drive. The name of the file is comprised of the current date and a serial number. For larger test series, making notes about the sequence of the tests is recommended to make classify them easier later on. -
Page 37: Updating The Firmware
Result: The directory structure of the USB flash drive should then look as follows: Plug the USB flash drive into the USB port of the MFM 10 which has to be switched off. Briefly de-energize the MFM 10 by pulling the power cord. Afterwards, reconnect the power cord and power on the unit. -
Page 38: Maintenance And Care
Maintenance and Care Maintenance and Care It is not necessary to open the housing of the device to commission and operate the Maintenance system. Opening the housing causes the immediate termination of all warranty claims! The connections and connection leads of the system must be regularly tested to ensure that they are free of defects and intact, in accordance with the applicable national and company-specific arrangements. - Page 39 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...
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