Arrester Disconnector

summary

As a special accessory of the arrester, the disconnector is used in series with the arrester. The purpose is to use power frequency short circuit current to make the disconnector act when the arrester is abnormal and fails, so that the grounding terminal of the disconnector can be automatically disconnected, and the arrester can be withdrawn from operation to prevent further expansion of the accident. The failure arrester is also provided with a visible separation sign to facilitate maintenance personnel and maintenance and replacement in case of failure, When the arrester is out of the normal working state, the disconnector is not used and has low impedance (compared with the arrester), which does not affect the original working state of the system and the protection characteristics of the arrester, ensures uninterrupted power supply, and makes the arrester truly meet the "maintenance free" use requirements. In foreign countries, such as Europe, America, Japan, Southeast Asia and other countries and regions, the distribution type Power station type and line type lightning arresters have generally been equipped with disconnectors, and disconnectors have gradually been widely used in power plants, railways, civil aviation, communications and other important power supply places in China. The separator can be divided into hot melt separator and hot explosion separator according to the use principle and performance. The hot melt release device uses the short circuit current flowing through the failed arrester to fuse the alloy fuse (or solder) in the release device to achieve the purpose of separation, and the hot explosion release device uses the short circuit current in the failed arrester to generate an arc in the release device to detonate the thermal explosion element to achieve the purpose of separation.

□ Overview of the latest release TLB-5, TLB-6 (or TLB - Ⅰ, TLB - Ⅱ)

Unlike foreign power grids (most of which are neutral point non effective grounding systems at KV and below), the fault current of arrester is mostly small current. In view of this feature and drawing on the advantages of foreign thermal explosive disconnectors (such as ABB in Sweden, GE in the United States, Joslin and other well-known companies), we have studied TLB-5 and TLB-6 new disconnectors, that is, they have the characteristics of rapid action, It can also withstand the specified current impact and action load, and all indicators meet the requirements of GB11032-2000 AC gapless metal oxide arrester and IEC.62 Requirements for Distribution Arrester Disconnectors.

□ Outstanding advantages

1. Wide operating current range

Combined with the characteristics of China's power grid, it can be disconnected under large power frequency fault current (>50A) or small fault current (50mA).

2. Fast disengagement speed

It can be matched with the reclosing function of the circuit breaker. It is not only applicable to various voltage levels and types of lightning arresters, but also applicable to different grounding systems (neutral grounded and ungrounded systems).

3. Strong impact resistance

At 2ms square wave and 4/10 μ S No action under high current impact.

4. High mechanical strength and good sealing performance before explosion

TLB-5 can be used with lightning arresters below 35KV, and TLB-6 can be used with lightning arresters between 35KV and 220KV.

5. Easy to install and replace

The screw type external interface is reliable and convenient to connect with the arrester in series, and it is very convenient to replace the disconnector once it acts. Ampere second characteristic