Overhead line fault indicator

Overview

CSM-SC0 four in one digital fault indicator (also called as overhead line short-circuit and ground fault indicator) is used for 10kV neutral point not grounding or the distribution overhead line of resistance grounded system. It accurately detects the grounding or short-circuit fault, and shows the red electromechanical flip and LED flashing indication.

Fault Detecting Criterion

1 Short-circuit fault criterion

l  Live line and last for more than 30s: current≥5A or grounded phase voltage≥3KV.

l  Fault startup conditions:

Line current ΔI ≥ 100A

l  Fault continued time: ≥20ms and ≤10S.

l  Line in power-cut status, current ≤ 5A and grounded phase voltage ≤1Kv.

2 Ground fault criterion (It can be set according to the protection settings of the substation exit’s zero sequence section I and section II)

l  Live line and last for more than 30s: grounded phase voltage≥3KV.

l  Transient current increment: ≥ 30A.

l  Fault continued time: ≥20ms and ≤5S.

l  Line in power-cut status, current ≤ 5A and grounded phase voltage ≤1Kv.

Features

l  Short-circuit fault detection:

Over-current mutation criterion of adaptive load current, you don’t need to set the parameters before delivery.

l  Ground fault detection

 It can detect the grounding current increment, and the detection is more sensitive and reliable. The parameter can be set before delivery.

l  Display mode

 5 highlight LEDs, and 3 red electromechanical flip instructions.

l  Reset mode:

8h reset time (be set before delivery) or intelligent reset (after emergency maintenance or the transmission returns to normal). Intelligent reset request the line current >10A or the line induced voltage >3kV.

l  Live installing and uninstalling

 Using a simple hypanthium and insulating stick to install and uninstall.

l  Anti rust design:

Pressing board is made of high quality nylon material, pressing spring is made of stainless steel, not with the wire "melting" as a whole; the wire clamping structure adopts stainless steel magnetic material and anti rust process design.

l  Anti miss-action design

It uses magnetic conductive circuit with large cross-section design, good magnetic permeability, high measuring precision and sensitivity. Also, it can show correctly in the rural network line small load current or current situations of small mutations, no miss-action.

l  Anti miss-operation design

It can prevent no-load switching inrush current misoperation, prevent the none-fault line branches miss-operation during the anti reclosing, against the fault line transient faults miss-action during reclosing.

Installation

Normal appearance and the fault occurs appearance of digital fault indicator.

Charged Installation:

Prepare one installing tool cavity, one spring remover, one insulating stick (>3 m) and indicators. First put the indicator into the installing tool cavity. Then use the spring remover to pull up the spring on top of the indicator and hook it up to the hook of the tool cavity. Then connect the tool cavity to the insulating stick and raise up the stick in order to let the indicator align to the overhead conductor. Then pull upward, the indicator can be installed on the conductor. In order to improve the accuracy of fault detecting, you’d better choose the conductor position near the electricity towers, leaving the tower insulators horizontal 30-50cm where the strongest voltage sensing signal to install the indicators.

Charged removal method:

Take out the tool cavity limit spring, let the tool cavity encase the indicator, pushing it up until its side hook hang on the edge of the indicator. Then drop down the tool, the indicator will be separate from the conductor.

Attention: Pay attention to your personal safety when you remove the overhead line indicators with insulating sticks. And prevent the indicators from falling off accidentally.