Underground & Overhead Cable Fault Detection
(A) Surge Generator
- Identify the Faults in underground power cables up to 440 V to 33 KV.
- Surge Generator set is locating the faults in High resistance or low resistance very efficiently.
- High voltage testing up to 20 KV DC.
- Built in ARC Reflection Filter.
- Limited burning capability is very unique feature in surge generator it is use in burn down the insulation at minor leakage (High resistance fault) point in cable.
- 1000 JOULES Energy on 5, 10, 20 KV Range.
- Suitable as thumper required for pinpointing of fault.
- Compact design.
- Suitable to operate on mains (220-230/240 VAC, 45Hz up to 60 Hz) or portable generator.
Limited Burning Capability (DC High Voltage Testing)
Limited Burning Capability is integral part of Surge Generator. It’s allows to burn down the insulation of cable by Limited Burning Capability. The Limited Burning Capability enables to change a high resistance fault to a low resistance fault in underground Power cables. Thus allowing Reflectometer to be used for low resistance fault pre-location.
Built in ARC Reflection Filter
ARC Reflection Filter is inbuilt in Surge Generator. ARC reflection filter used for fault location in low, medium and high voltage power cables. The used inductive ARM (Arc Reflection Method) technology is a result of a discharge of the surge generator and the in the integrated inductivity and causes a low resistive arc at the fault spot. Simultaneous the ARC Reflection Filter protects the Reflectometer from the high voltage in the cable. The short circuit caused temporarily by the arc results in a clearly visible reflection of the measuring pulse.
Thumper for Pinpointing of Fault:
The surges produced help in pinpointing the fault and tracing the route of the cable when used with acoustic fault locator.
Surge generator generates D.C. high voltage for pressure testing of the underground cables to find out faulty phase and the breakdown voltage with leakage current. 1000 JOULES Energy on 5, 10, 20 KV Range.
Surge Generator set safety precautions keep in mind when design and developed the instruments:
- Zero Start Interlock.
- Range Interlock.
- Automatic Discharge.
- Over Load Protection.
Application of Surge Generator:
Surge Generator with Pre-location (Reflectometer)
Pre-location Reflectometer to assist power cable fault location technicians in pre-locating and pre-determining distances to faults existing in power cables. It gives a direct reading in meters or kilometres to the fault position. Fault distances can also be determined from the far end of the cable by simply moving two cursors to starting pulse and fault point on the display screen. It is capable of locating low resistance or high resistance faults with the help of Surge Generator.
Pre-location Operating Mode:
Surge Generator is capable of pre-locating distance to fault in two different modes.
In the Reflectometer mode the instrument transmits a low voltage pulse which is reflected off the far end of the cable. Any impedance mismatches (i.e. Joints, open or short circuits) along the cable are also reflected. The waveforms are easy to analyze. This is useful for open and short circuit faults.
ICM /DECAY Mode:
In the Impulse Current Mode a high voltage discharge generated by a surge generator is applied to a faulty cable until the fault breaks down. Thus the wave is then reflected back to its source. Upon arriving at the source it is reflected back into the cable. This continues until the energy is depleted. Reflectometer will capture and store the current waveform flowing in the cable and display it for analysis.
Surge Generator with Digipoint for Pinpointing Of exact fault point:
In most cases, the low voltage cables have a length quite limited (average not more than 200 meters) and then the solution faster and more convenient to locate the fault point is to take advantage of the acoustic method that can be used when the failure occurred between phase to phase or phase to the screen.
At the point where the fault occurs, a discharge acoustic energy is perceived and amplified with an appropriate acoustic detector on the ground surface. The point with the highest intensity discharge corresponds to the location of the fault.
With the use of the Surge Generator, as well as the acoustic is also measured the time between the arrival of the magnetic wave and the sound. Therefore approaching the fault point to the time difference becomes progressively smaller until reaching a minimum value above the fault.
The main parameters detected by the detector are:
- Relative distance from the magnetic and acoustic fault in ms. The lower the value the closer the fault.
- Intensity of the magnetic signal present at the location to confirm the presence of the cable and its location.
- Confirmation of the acoustic signal.
- Confirmation of the magnetic signal.
|Maximum Surge Energy||1000 JOULES on each range.|
|Surge Sequence||Manual / Auto (3 to 15 Sec).|
|Instrument Input Supply||220-230/240 VAC, 45Hz up to 60 Hz.|
|Surge Generator Output:|
|Output||Voltage Range||Short Circuit Current|
|I||0- 5 KV.||200 mA.|
|II||0- 10 KV.||100 mA.|
|III||0- 20 KV.||50 mA.|
|Operating Temperature||-10°C to 50°C.|
|Storage Temperature||-10°C to 60°C.|
|50 X 50 X 80 cm3.||115 kg approx|