An understanding of the characteristics of seconds, we can see from the Joule's law Q = I2 * R * T, series circuit, the fuse is essentially the same R-value, the heat made proportional to the square of the current I, and fever T Which fuse is proportional to Qinhuangdao, ie: when the current is large fuse Which Hohhot, time required to melt the fuse is shorter. And when the current is small, the time required to melt the fuse is longer, even if the heat accumulation rate is less than the thermal diffusion rate of Nanjing Which fuses, fuse temperature does not rise to the melting point, the fuse will not even blown. So, in a certain overload current range fuse, when the current returns to normal, the fuse is not blown, can continue to be used. According fuse breaking current range can be divided into general purpose fuses, fuse, and the full range of back-up fuses. General purpose fuse breaking current is greater than the current range is 1.6 to 2 times the rated current starting from overload, the maximum breaking current range. This fuse is mainly used to protect power transformers and general electrical equipment. Backup fuse breaking current range is from overload current greater than the rated current of 4 to 7 times until the maximum breaking current range. This fuse is often used in tandem with the contactors, overload current of less than 4-7 times the rated current range, by breaking the contactor to achieve protection. Mainly used to protect the motor. Which fuse Harbin | Huayi Electric Power (certified) | fuses provided by Xian Huayi power plant. Xian Huayi power plant (www.xahy.com) is a leader in Xi'an, high voltage circuit breakers, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Huayi power in leadership with the staff warmly welcome all inquiries negotiations to create electricity Huayi a better future.