1, no load protection smooth start-up process, such as when the lighting circuits, resistors, electric furnace melt rated current equal to or slightly greater than the rated current of the load circuit: the following methods to select the rated current can melt. 2, a single long-term protection of the motor current can melt maximum starting current selection, the following formula can be selected: IRN ≥ (1.5 ~ 2.5) IN where IRN-- melt rated current; IN-- rated motor current . If the motor frequent starting, where appropriate coefficient can be increased to 3 to 3.5, in particular should be based on the actual situation. 3, protecting multiple motors (supply mains) IRN ≥ permanent jobs (1.5 ~ 2.5) IN max + ΣININ max- largest capacity single motor rated current. ΣIN remaining motor rated current. Circuit breaker can achieve short-circuit and overload protection, but not the same principle, it is the end of the current through the magnetic effect (electromagnetic release) to achieve high-voltage fuse circuit protection Huizhou, by thermal effect of current overload protection (not blown, and more do not replace the device). Specific to the actual high-voltage fuse in Foshan, when the circuit of electricity load for a long time with a load close to the fuse, the fuse will gradually heated until the fuse. Like said above, the fuse is a result of interaction of current and time to play the role of the line to protect, it is disposable. The current in the circuit breaker is suddenly increased, exceeding the load circuit breaker will automatically disconnect, it is an instantaneous current of the circuit to increase the protection of high-voltage fuse, for example, when the leakage is large, or short, or transient current is large protection. When pinpoint the cause, you can continue to use the closing. As mentioned above, the fuse is a result of current and time interaction, and the circuit breaker, as long as the current one will trip over the set value, the time almost can not consider the role. A circuit breaker is used in low voltage distribution components. There are also some places suitable fuses. Huizhou high voltage fuses, Huayi Electric Power (certified), high voltage fuses provided by the Xi'an 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.