Surge protector model BY10 from Selong has a 15kA normal discharge current. Delivery lead time is seven days

Suppliers target production growth by expanding their export markets through quality assurance and international approvals.

Most of today's manufacturers of surge protectors in Wenzhou in Zhejiang Province are private companies, some of which are family-owned enterprises. Delixi Group Co. Ltd, one of the leading surge protector makers in Wenzhou, says that production of surge protection devices is a well-developed industry. Even small factories have very flexible business policies and are capable of short delivery lead times.

Many makers in Wenzhou began to produce surge protectors in 2000. However, due to the increasing number of makers but decreasing prices and profit margins, some of them dropped out of the line and have turned to related products.

Large-scale companies make sure to apply for certifications and product approvals as well as increase brand awareness. Delixi has obtained ISO 9001, ISO 14001 and OHSAS 18001 certifications. Its surge protectors have KEMA certification and comply with IEC standards. The company's R&D center in Germany serves as its technology base.

Most Wenzhou makers offer a wide range of surge protectors and related products. The industry has developed a complete supply chain for nearly all raw materials. Metal oxide varistors (MOV), fuses and plastic parts can all be sourced from mainland China suppliers.

Youli Holdings Group CANTOR High Voltage Electric Co. Ltd, also one of the major makers in Wenzhou, produces an average of 30,000 surge protectors every month. The company's total capacity for the product is 100,000 units, which accounts for 25 percent of total production.

Fans Zheng, Cantor's sales manager, is confident that sales will grow 300 percent in 2007 as the company expands its marketing and sales channels. The company is also confident the quality of its products will boost sales. Its products have KEMA certifications and are compliant with IEC291, 282, 644, 787 and the national GB/T15166, 15166.2 standards.

Zhejiang Selong Ele. Appliance Co. Ltd's surge protectors are used mainly in high-voltage electrical systems, lighting signal systems and telecom systems. With about 350 employees, the company produces 160,000 units of surge protectors and surge arrestors monthly. Its products are used by China Telecom, Qingdao University, and some buildings and public infrastructures on the mainland.

Selong's factory has been certified to ISO 9001 and ISO 14001. In order to establish a long-term partnership with big electronics product makers such as Samsung, Panasonic and Hitachi, the company aims to obtain TS 16949 approval in 2007.

Delixi provides a full range of high- and low-voltage switchgear sets. Aside from surge protectors, its product line includes circuit breakers, power supplies, fuses, relays, capacitors, switches, instruments, and meters. The company has provided products for many national projects including space flights, airports and railways. Its surge protectors are mainly used in telecom base stations and buildings.

To remain competitive, manufacturers ensure their products meet international standards and strict requirements of their clients. Selong's BY1 and BYX series of surge protectors, for example, have been recognized in 2005 by the National Hi-tech Products Program sponsored by the Ministry of Science and Technology.

Selong's BY1-D series of surge protectors is installed in LPZ1, or the intersection of LPZ2 and LPZ3 zones, and are applied in switchboards, computers and other electronics equipment. One distinctive feature of the product is that its surge protector module has an invalidation deviation setting. When the MOV burns out, the invalidation deviation setting will remove the protector from the high-voltage network and the red indicator light will turn on.

The BY1-D surge protector also has an alarm system. When the protector functions properly, the indicator light turns green, but when the protector module fails, the indicator light turns red and the alarm will buzz. The voltage of BY1-D products ranges from 140V to 420V and the protective voltage ranges from 0.8kV to 2kV. Maximum response time is 25ns. These surge protectors also have a protective level of IP20, and use 10A to 16A fuses.

One of Delixi's bestsellers is the CDY1 series used for the equal potential link of TT, IT, TN-S and TN-C-S, low-voltage power systems of AC 50Hz/60Hz, 400V or less. The products can protect electric networks from high voltages caused by lightning and high electric surges. The CDY1-10D SPD has a 385V maximum continuous operation voltage, 10kA nominal discharge current, 20kA maximum discharge current, 25ns response time and 20µA leakage current.

Selong exported 40 percent of its total production in 2006. In 2007, it targets to increase exports by 30 percent. Products for exports bear TÜV, VDE, NEMKO, CB and CE approvals.

Over 50 percent of Delixi's products are exported worldwide, making it the top 20 export companies in Wenzhou. Export manager Zhu Yifang expects a slight price increase in 2007 due mainly to high raw material cost. Zhu notes that competition among low-end surge protectors has been quite fierce in mainland China. The company plans to avoid this price war by sticking to high-end applications.

More than 95 percent of Cantor's products are exported to Europe, South America, Africa, the Middle East and South Asia. Zheng forecasts stable prices for surge protectors in 2007.

	Zhejiang map

Wenzhou, located on the southeastern coast of Zhejiang province, is the economic, cultural and communications center of southern Zhejiang. With a land area of 11,784 sq km and a population of 7.7 million, the city has been a principal trading port in mainland China since the Tang Dynasty.

Since the 1980s, the development of Wenzhou's economy has evolved into what is now known as the "Wenzhou Economic Model", which has paved the way for the city's industrialization and impressive development and economic growth.

Low-voltage electrical appliances, as well as garments, shoes and hardware are the city's backbone industries. According to the Wenzhou Municipal Bureau of Statistics, Wenzhou's GDP in 2006 reached $23 billion, a 13.3-percent increase from 2005. Its per capita GDP reached $3,054.

In 2006, the city's import and export value was $9.89 billion, 48.45 percent of which was generated by private companies. Statistics show that the average wage rate of formal workers in Wenzhou was RMB22,758 in 2006, equivalent to about $2,917.