【正文】 The measurement procedure ?As voltage gradients induced by the current flowing back from the fault position exist around the earthing point of the generator, the measure might be elevated () indicates the direction of the fault position at this point. ?At halfway point between the generator and the fault position, the signal strength reaches a minimum () signal strength increases again. ?The maximum signal strength is measured when one of the earth spikes is directly above the fault. ?If the fault is exactly between the two ear the indicator unit does not display a reading. ?If the fault position is passed by, the polarity changes (pos. 5) indicator unit points to the other direction. Display Messbildschirm Men252。F 60 kV 1,7 181。F 35 kV 5,5 181。F 40 kV 4,8 181。F symmetrical) 25181。F ? Test frequency: ( – ) (automatic frequency adaption) NOTE: The VLF Sinus 34 has been designed for the IEEE market for maintenance testing cables up to 25 kV. 68 ? 0,7 181。 ? Decrease of the insulation breakdownstrength will in the end lead to cable failures。F ?Test frequency: ( – ) (automatic frequency adaption) First test vans has successfully been delivered to EDF France, integrated in Centrix 1 and 3phase. Vertriebstagung Baunach 2023, (c) SebaKMT 2023, all rights reserved. VLF Tan Delta System description / theoretical explanations SebaKMT 2023 VLF Tan Delta Tan Delta basics ? All MV and HV power cables have a high voltage life expectancy。F 40 kV 7,7 181。F 38 kV VLF CR6025181。F 36 kV 21,0 181。F 40 kV 5,0 181。F 12 kV VLF CR40B (899004500) 181。 0 , 1 % 。 ? New, high performance connectors! (c) SebaKMT , all rights reserved Sensor Adjustable handle Exchangeable tips Active Elektronic – the evaluation happens pletely in the sensor! Housing: Dual shell die casting with telescopic handle Soft rubber rims for acoustic shielding Dimensions: Diameter 230mm (at the outer lip) Height: 140mm Handle length: 450 … 750mm Weight: Sensor mit Teleskopstab ca. 2 kg Dynamic range: acoustic channel 110dB Dynamic range: magic channel 110dB Frequency range: 100 ... 1500Hz 4 Filter settings: OFF 100 … 1500Hz Low pass 100 … 400Hz Band pass 300 … 500Hz High pass 700 … 1500Hz (c) SebaKMT , all rights reserved Receiver Jogdial ON/OFF Manual Mute Key The receiver is only for the display of the data generated from the sensor and the signal processing of the signals for the head set. Dimensions (with rubber frame): 65 mm x 225 mm x 100mm (H x W x D) Weight: app. 1kg (incl. Batteries) Supply: 6 pieces Mignon cellsTyp IEC R6 (AlkaliMangan) Operation time: Mignon cells with 2500 mAh capacity: 10 Std. Display: Color TFT 320x240Pixel Adjustment Selectable limitation to 84 dB(A), Volume Akustic Gain: 120dB (c) SebaKMT , all rights reserved Tracing A green cable symbol beneath the sensor symbol in the center of the digiPHONE+ display shows the side position of the sensor in relation to the cable trace. This ensures automatically, that the user remains with the sensor directly on top of the cable, which makes the fault location more accurate but also easier. Weak fault are much faster detected and located. A cross measurement is not required, since the system is positioned automatically in theYaxis on top of the cable (c) SebaKMT , all rights reserved The Compass The ?Compass“ function of the digiPHONE+ recognises from the data, especially from the difference time measurement, if the user is moving towards the fault. This is indicated by the arrow in the display. The user follows the arrow and ppoaches automatically the fault position If the digiPHONE+ detects an increase of the difference time, it means, that the user has passed the fault already. In this case a bent arrow indicates this and requests the user to move backward. Before the fault: The new value is lower than the old difference value After the fault: The new value is higher than the old difference value (c) SebaKMT , all rights reserved MFM 10 (c) SebaKMT , all rights reserved (c) SebaKMT , all rights reserved 41 Example from Greece 42 Bad workmanship as standard problem More and more units are installed by unexperienced cheap service panies worldwide. ? MFM10 Sheath fault locator required Example (c) SebaKMT , all rights reserved 43 MFM 10 (c) SebaKMT , all rights reserved Die Optical appearance 44 ? Clear front end with few operating elelments ? Also in the new MFM 10 the easygo priciple with jogdial and according optical feedback of the jogdial motion is realised ? Intuitive easiest operation with a large display ? Less connection cables ? Solid Pelicase (c) SebaKMT , all rights reserved 45 MFM 10 Features ? Test voltage up to 10kV DC (bipolar!) ? Up to 750mA continuous current driving capability (depending on output voltage (30mA at 10kV) ? within certain limits useful as burn unit! ? Flicker as well as ignitions of faults during testing are recognized and displayed ? Wide range mains supply 88 to 264 V ? Fault locating using the well known voltage drop method?improved accuracy due to lownoise preamplifier ? Logging is done by Easyprot ? Easiest , menu guided operation ? For prelocation the MFM 10 checks for wrong connections and informs the operator accordingly. ? EasyGo rotary knob supplemented by a touch screen (c) SebaKMT , all rights reserved The Handling 46 ? Easy, menu guided operation with rotary encoder and touch screen ? Weight reduction of more than 30% pared to the MFM 51 by new technologies ? Only one single HV connection cable, the permits testing, prelocation and pinpointing without reconnecting ? The test of all connected test le