Views:183 Author:Site Editor Publish Time: 2021-04-01 Origin:Site
Fault indicator refers to a device installed on power lines (overhead power lines, cables and busbars) to indicate fault current. Most fault indicators can only identify and indicate electrical short circuit faults by detecting the characteristics of the power short circuit current.
The line fault indicator is an electromagnetic induction device that can reflect the passage of electric wire short circuit current and a fault sign (red card) appears. Install this fault indicator along the distribution line, once the line fails and short-circuit current flows, the fault circuit indicator will act and the fault sign red card will appear. Then patrol along the line, the fault indicators from the power supply side to the fault point all show red cards, and the fault indicators after the fault point do not show red cards, it can be judged. The fault point is between the last red card point and the first non-red card point.
1) According to the application objects, the fault indicator can be divided into three types: overhead type, cable type and panel type.
The overhead fault indicator sensor and display (indication) part are integrated in one unit, and are mechanically fixed to the overhead power line (including bare and insulated wires). The overhead fault indicator is generally composed of three phase sequence fault indicators. And it can be loaded and unloaded with electricity, and it will not alarm by mistake during the loading and unloading process.
The cable fault indicator sensor and display (indication) part are integrated in one unit, and are mechanically fixed on the cable line (busbar), usually installed on power distribution equipment such as cable branch boxes, ring main cabinets, and switch cabinets. It is composed of three phase sequence fault indicators and a zero sequence fault indicator.
The panel-type fault indicator is composed of a sensor and a display unit. Usually the display unit is embedded in the operation panel of the ring network cabinet and the switch cabinet. The sensor and the silicon display unit communicate with each other by means of optical fiber or wireless.
2) According to whether it has a communication function, the fault indicators are divided into local fault indicators and communication fault indicators.
The local fault indicator detects a line fault and flops or flashes on the spot. It does not have the communication function, and manual intervention is still required for fault finding.
The fault indicator with communication is composed of a fault indicator and a communication device (also called a concentrator). The fault indicator detects a line fault and can not only flop or flash an alarm on the spot, but also transmit fault information to the communication through a short-range wireless device, the communication device sends the fault information to the master station through the wireless public network or optical fiber. With communication fault indicator, it can also be equipped with telemetering and telesignaling functions, and report telemetering information, switch opening and closing, energy storage and other state quantities to the master station.