Aging of Varistor Under Electric Shock

Sep. 30, 2021

With the development of science and technology, the application fields of varistors have become more and more extensive. In daily life, users will encounter many problems. Why do the repeated low-strength electric shocks on varistors on lead to accelerated aging? In this article we will discuss the reasons behind.

The disadvantage of the varistor is that it is easy to age. In most cases, when the P-N junction is overloaded, it will cause a short circuit and cannot return to the normal state. The diode element in the varistor is broken down under the repeated action of electric shocks. The low resistance linearization of resistors is gradually intensifying, the varistor voltage is getting lower and lower, and the leakage current is getting larger and larger.

As the temperature of the MOV body increases, the leakage current becomes larger, forming a vicious circle, causing the temperature of the MOV to rise to the ignition point of the outer encapsulation material. This situation is called a high-impedance short circuit (about 1kΩ). Joule heat causes the MOV to heat up and flow into the weak spots. The weak spot materials melt and form a short-circuit hole of about 1kΩ. The power supply continues to push a larger current into the short-circuit point, forming high heat and catching fire.

The research results show that if the varistor has manufacturing defects, it is prone to early failure. The repeated action of low-strength electric shocks will also accelerate the aging process and make the aging failure appear early. In summary, we can know that the failure of the varistor is also related to the manufacturing process, so it is very important to choose a formal manufacturer.

Aging of Varistor Under Electric Shock

Dongguan Zhixu Electronic Co., Ltd. (also JYH HSU(JEC))  has a full range of varistor and capacitor models. JEC has passed ISO9001:2015 quality management system certification; JEC safety capacitors (X capacitors and Y capacitors) and varistors have passed national certifications of the main industrial powers across the world; JEC ceramic capacitors, film capacitors and super capacitors are in compliance with environmental protection indicators. Welcome to contact us for free samples and any questions.

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