MOA is composed of metal oxide varistors,housing(porcelain or silicon rubber),base,upper cover,grading ring etc.Our products have excellent performance in accordance with IEC international standard IEC600 99-4(2000) and China National Standard GB11032-2000 for "Alternating Current Gapless MOA".Polymeric housed MOA manufactured by AMTECH features small size,lightweight,simple manufacturing process,good sealing,explosion-proof,long working life,wounded-proof,high pollution resistance and reduced line maintenance,etc.
MOA Classification Code
Gapless arrester electrical parameter
|Type||Rated voltage||MCOV||Residual voltge(kv)|| |
Wave impluse withstand current
2000µ S square
4/10µ S high
|Steep impluse current||Switching impluse current|| |
8/20 µ Lightning impluse current
Zinc-oxide Lightning Arrester is the most advanced Over-Voltage Protector at present in the world. The voltage current characteristic of the varistor has been changed compared with traditional carborundum arresters due to the multiple metal oxide materials application in the core element-varistor,which has greatly improved the varistor's throughput capacity and brought thorough change to arresters'characteristics.
When arrester is under normal voltage,there is only microamp current through it .When it is under high voltage,arresters'excellent nonlinear voltage current feature gets into play,so the current through arresters will reach thousands of amperes and the arresters are at conducting status,releasing over-voltage energv to effectively protect the power transmission equipments from damage caused by over voltage.
Application and features
Zinc-oxide lightning arrester is protective equipment for electrical devices in A.C.power system from damage caused by over voltage or over-voltage operation.
Actuation ampere-second characteristic
A disconnector must work when there is faulty current. According to the national standard GB11032, dynamic ampere-second characteristic is to be tested at power frequency current 800A,200A, 20A, 5A virtual value at China National Center for Quality Supervision and Test of Insulators and Surge Arresters. The test results are shown in next table.
Test results of operating ampere-second characteristic
Characteristics of MOA with disconnector
MOA is connected with wire via the disconnector. Under normal conditions,when lightning current and operating over-voltage current pass through MOA, the disconnector will not be actuated; under abnormal conditions,when MOA fails to operate,the disconnector will be actuated and the wire connected to the MOA will be cut off automatically, thus maintaining the continuous power supply and keeping enougf insulating distance between the wire and MOA.
Disconnector Capacity of Current Impulse Withstand and Operating Duty
The disconnector is installed in series with MOA. When MOA works properly, non-actuation of the disconnector guarantees MOA's normal performance. As National Standard GB11032 stipulates that the disconnector should withstand:
a.Long duration current impulse test;
b. Loading test;
The type test made by China National Center for Quality Supervision and Test os Insulators and Surge Arresters proves that the disconnector has non-reaction capability when withstanding 2ms 600A current impulse and 4/10µS 100kA high current loading.
Main Technical Parameters
A. Main technical parameters the same as MOA of corresponding type;
B. See the following Table for outline dimensions and weight.
Main parameters of polymer housed MOA with disconnector
|Type of MOA||Fig.|
Contact us if you need more details on Over-Voltage Protector. We are ready to answer your questions on packaging, logistics, certification or any other aspects about a. C. Power System、Lightning Arrester. If these products fail to match your need, please contact us and we would like to provide relevant information.
Product Categories : MOA without gaps