2. Major shortcomings and weaknesses of the fuse must be replaced 1) fuse fuse failure; 2) protection function of a single, only some characteristics of inverse time overcurrent, overload, short circuit and ground fault protection are used here; and 3) the occurrence of a phase fuse when the three-phase motor will lead to adverse consequences of the two-phase operation, closure fuses, of course, an alarm signal can be used with a fuse to be filled, a fuse to disconnect the three-phase phase; 4) remote control can not be achieved, the need and the electric knife Switch, switch combination is possible. An understanding of the characteristics of seconds, we can see from the Joule's law Q = I2 * R * T, series circuit, the fuse R value is essentially the same, the heat made proportional to the square of the current I, and heating time T proportional, ie: when the current is large, the time required to melt the fuse is shorter. And when the current is small, the time required to melt the fuse on longer, since the complex fuse, even if the heat accumulation speed is less than the thermal diffusion rate, the temperature does not rise to the melting point of the fuse, the fuse will not even blown . So, fuses, in a certain overload current range, fuse factory direct, when the current returns to normal, the fuse will not blow, you can continue to use. Fuses price _ Huayi Electric Power (Online) _ fuse provided by Xian Huayi power plant. Xian Huayi Electric Power Equipment Factory (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. In Huayi Electric Power leadership with the staff warmly welcome all inquiries negotiations to create Huayi electricity better future.