Fuse symbols and letter code are common symbols and code used in electrical engineering to indicate the type and characteristics of fuses. In this paper, the fuse symbols and letter codes will be elaborated from various aspects.

The most obvious difference between polymer self-repeating fuses and ordinary fuses is their self-repeating nature. Although both provide overcurrent protection, polymer reclosing fuses can provide protection for many overcurrents, whereas ordinary fuses, once blown, must be replaced in order for the circuit to function properly.

To select the type of blade fuse, we usually determine the load type first, and select the fast-acting fuse or slow-acting fuse according to the load type. After determining the type of fuse, we will select the appropriate fuse model according to the actual usage, such as the installation environment, the existing fuse material system, and the size of the demanded fuse capacity.

A polymer cutoff consists of a polymer matrix and carbon black particles that make it electrically conductive. Since the polymer self contained fuse is a

Different types of fuses blow at different speeds and protect in different ways. Depending on the blowing speed, we can categorize fuses into fast blowing fuses and slow blowing fuses.

the function of a fuse is to automatically cut off the power supply when the current in the circuit exceeds a set value, preventing overloading, short-circuiting, malfunctioning and equipment damage.

An explosion-proof fuse is a fuse that does not explode or burn on the basis of the fuse itself blowing to cut off the current. If an explosion-proof fuse is correctly placed in the circuit, the safety will be greatly improved.

The breaking capacity of a fuse refers to the maximum current value under the rated voltage at which the fuse can safely break the circuit without breaking. Fuses can be categorized into high breaking capacity and low breaking capacity according to their breaking capacity.