Cable Fault Location Principle and Instrument

Wire and cable fault location equipment has rised as a result of cable applications, using the progress and development of electronic technology, after having a century of changes, the key still but looks Nisshin. As a result of few cable systems failure, positioning experience accumulate very slow. Using the use of automation, technology, the instrument has made substantial progress. Power Cable Fault Locator is utilized to do this work. There are four steps of cable fault location process.

 

(1)CABLE FAULT TYPE JUDGMENT

Should first serious take a look at the failure of cable throughout, fully understand the faulty cable, and detailed records, which will help find fault faster. Positioning method and sort of cable fault. Judgment cable fault type enables you to measure the insulation resistance or DC voltage test. Shaking table or digital megger relative measurement fault cable and white, and metal outer sheath-ground insulation resistance value. Point of failure the measured worth of the insulation resistance measuring voltage, the condition of the environment, sometimes values ??vary greatly. At different voltages, to see the changes over time, the insulation resistance of the fault point, combined with the characteristics from the cable and laying path, so that you can interpret many of information, as an example, the sort of failure as well as the possible positions.

(2)FAULT PRETARGETING

Bridge method and wave reflection way of the the pretargeting two main means. The proportion of resistance on the point of failure on sides of the cable core resistance and instrument constitutes the Murray Bridge, can be a traditional classic cable fault location. Positioning the bridge equipment low cost, simple operation, and had widespread use. Traditional positioning from the bridge, the rated output voltage only 500V, unable to locate high impedance fault. The big quantity of applications, cross-linked polyethylene cable breakdown is difficult to form the conductive zone breakdown point resistance is high, or even have the ability to withstand our prime voltage was flashover type breakdown. Using the positioning of the popularity of wave reflection method, the method of application of the bridge gradually reduce, not known towards the new cable users.

(3)PATH DETECTION

The precise positioning ahead of the point of failure, you need to know the position and direction of the underground cable, the relevant details are often inaccurate, not even. With a dedicated path analyzer measured to find the position and direction of the underground cable. Path analyzer uses the audio induction method to appraise the cable path. The audio generator for the the measured cable input audio signal current on the headend, the receiver is received on a lawn fault cable generates a magnetic signal to its path and depth measurement.

(4)ACCURATELY FIXED

Depending about the kind of fault, there are various ways and instruments for pinpointing. Cable Fault Locator is a necessity. Fault Location in Power Cable is designed to locate cable faults, pinpointing the fault location, route tracing, cable identification, voltage withstand make sure cable information management. It could locate all kinds of cable faults for many voltage level cables, including open circuit, short circuit, low insulation, high insulation and flashover faults, etc. Most power cables were buried underground, invisible, and unrealistic, with modern new power cable fault testing equipment, it may discover the fault point quickly, solve problems immediately and restore power source.