MOA Metal Zinc Oxide Varistor Resistor Disc With KEMA For Surge Arrester

MOA Metal Zinc Oxide Varistor Resistor Disc With KEMA For Surge Arrester

Introduction:

A varistor remains non-conductive as a shunt-mode device during normal operation when the voltage across it remains well below its "clamping voltage", thus varistors are typically used for suppressing line voltage surges. However, a varistor may not be able to successfully limit a very large surge from an event like a lightningstrike where the energy involved is many orders of magnitude greater than it can handle. Follow-through current resulting from a strike may generate excessive current that completely destroys the varistor. Lesser surges still degrade it, however. Degradation is defined by manufacturer's life-expectancy charts that relate current, time and number of transient pulses. The main parameter affecting varistor life expectancy is its energy (Joule) rating. As the energy rating increases, its life expectancy typically increases exponentially, the number of transient pulses that it can accommodate increases and the "clamping voltage" it provides during each transient decreases. The probability of catastrophic failure can be reduced by increasing the rating, either by using a single varistor of higher rating or by connecting more devices in parallel. A varistor is typically deemed to be fully degraded when its "clamping voltage" has changed by 10%. In this condition it is not visibly damaged and it remains functional (no catastrophic failure).

Specifications:

D28 Metal Oxide Varistor(MOV):

About us:

Yongde holds the quality policy of being 'the technical forerunner, supreme in quality, supremacy of customers, and innovative progressing', so that our products and services successfully satisfied our users. We warmly welcome friends and customers from home and abroad to contact for exchanges and corporations. We also welcome feedbacks from our user communities.

Hangzhou Yongde Electric Appliances Co.,Ltd was founded in 1993. As a high-new-tech enterprise in Zhejiang province, it is about 15 kilometers from downtown area.

Our Company is one of the recommended model companies for national power grid construction and transformation. We specialized in manufacturing of 0.22-500kv metal oxide arrester of all types and applications and 10-252kv outdoor high-voltage disconnecting switch.

Currently, our company employs 180 Staffs, with 23 technically-titled and 15 senior technical title holders, who organize a high standard scientific research and development team. Every year we invest many research funds for new product development and acquiring advanced production and testing equipment each month.

Through developing new generations of high-tech products, the technology and production level maintains a leading position in the national level.

The newly developed GW37, GW38 series outdoor high-voltage disconnecting switch have been proved by authorities, which has achieved ideal operating results and won good praise from users.

Our company has a variety of CNC equipments of over a hundred units. In 2001, our company passed the ISO9001 quality inspection, and in August 2010 adopted itself to the ISO9001-2008 version of reinspection.

The annual production capacity of the company is about Sixteen million U.S Dollar, with well equipped means of inspection for raw materials and purchased spare parts. Each procedure in the manufacturing process is under strict control and supervision. The inspection equipments and instruments are advanced and reliable which effectively guaranteed our product quality.

Yongde holds the quality policy of being 'the technical forerunner, supreme in quality, supremacy of customers, and innovative progressing', so that our products and services successfully satisfied our users. We warmly welcome friends and customers from home and abroad to contact for exchanges and corporations. We also welcome feedbacks from our user communities.