L ightning arrester is all kinds of electrical equipment of power system(transformers , reactors , capacitors , generator, motor, PT, CT, circuit breaker, contactor and all other high-voltage electrical equipment insulation coordination based) , determined by the protection ability of the arrester and power system all electrical equipment insulation index(short-time power-frequency
withstand voltage , lightning impulse voltage and switching impulse voltage withstand etc . ) .
Metal oxide arrester(Metal Oxide surge A rrester,referred to as MOA)is the most advanced conventional arresters in products . Core components using multiple metal oxide powder of zinc oxide based firing , with nonlinear volt -excellent safety characteristics of steep waves , fast response , large flow capacity.
2 、A pplication and implementation of standards
MOA products for use in AC 220KV and below power generation transmission , substation , distribution system , internal system for lightning and overvoltage amplitude limit prescribed level , is the foundation of equipment insulation coordination of the entire system . At the same time , this product is not intended to limit the resonance over voltage , system harmonic elimination need to use other way.
MOA product model according to IEC 60099-4 " lightning arrester product model establishment method"compilation , gapless product implementation of IEC 60099-4 "the exchange without gap metal oxide lightning arrester" standard: a gap product implementation of IEC 60099-4 " metal oxide arrester with series gap" standard . T he important parameters of the undefined following standard and the method of preparation ,"according to DL/T620- 1997 AC electrical device overvoltage protection and insulation configuration" request correction .
3、T he normal conditions of use:
T he environment temperature:+40 °C not higher,not lower than -40 °C;
A ltitude: not more than 2000m;F requency: 50± 2Hz:60± 2Hz;
Seismic intensity of 7 degrees and the following;T he maximum wind speed: 35m/s;
Cleaning free conditions:secondary pollution and the following areas;
Continuous operating voltage gapless product long-term power frequency voltage not exceeding MOA;
4 . Method of installation;
Before installation should model and use place to check the MOA product line ,surface contamination and cleaning products . Rated voltage below 25KV MOA products ,should be fixed vertically in the protected equipment shell or a special bracket . T he cross-sectional area of not less than 1 0 mm multi-strand flexible cord ,the MOA terminal and
phase(bus)connection; will MOA terminal and ground connection(the grounding resistance is less than 10 . ) .
Rated voltage 42Kv and below MOA ,the cross-sectional area of not less than 16mm² multi-strand cord . F irstly the
base is fixed on the base ,are vertically installed arrester unit ,according to the way of wiring .
7. Such as the need to install a counter, counter series should be in MOA low voltage installation method ,shown in F igure
8~ 10 .
L ine arrester for hanging , product installation should avoid arrester under line tension .Other matters needing attention , through consultation by the two sides .
5 .Matters needing attention
I n order to prevent damage in transit , delivery should be checked after arrester appearance ,correct silicon rubber umbrella skirt deformation , clean porcelain sleeve contaminated . Defect depth more than lmm or area of more than 25mm
2 , May not continue to use the .
Storing arrester should pay attention to prevent strong acid , alkali damage; prevention of heavy crushed umbrella skirt;prevent cut weapon umbrella skirt; ventilation and
In order to prevent the internal voltage division changes , lightning arrester is not recommended charged cleaning .
Lightning arrester warranty for two years from the date of delivery (or according to the technical protocol approved by both parties request execution) , the warranty period of non- use of improper fault ,free repair or replacement of the factory.
Beyond the normal conditions of use ,should be ordered to request the specific conditions of use , bilateral coordination after delivery.
