Selection and Application of Fuses

Selection and Application of Fuses

Types of circuit breakers

The types of fuses are numerous, including those for high voltage and low voltage use. We will focus on introducing the most commonly used fuses in current low-voltage control systems.

Plug fuse

It is commonly used at the end of lines with voltage levels of 380V and below, serving as short-circuit protection for distribution branch lines or electrical equipment. Some fuse holders have indicator lights, which turn on after the fuse protection melts, essentially paralleling a resistor and diode across the fuse. When the fuse is intact, the indicator light is short-circuited and does not illuminate, allowing for quick assessment of the fuse's condition.

Spiral fuse

Spiral fuse, the upper end cap on the fuse body has a fuse indicator, commonly used in machine tool electrical control equipment. Spiral fuse. It can interrupt large currents and is used for short-circuit protection in circuits with voltage levels of 500V and below, and current levels of 200A and below.

Selection and Use of Fuses

The rated current of the fuse is different from the rated current of the fuse element, so when selecting a fuse, the first step is to determine the specifications of the fuse element, and then choose the fuse based on the fuse element.

The rated current of the fuse should be greater than or equal to the rated current of the fuse element.

The rated voltage of the fuse should be greater than or equal to the line voltage level.

The rated currents of the fuse elements at each level in the circuit must be coordinated accordingly, ensuring that the rated current of the fuse element at the previous level must be greater than that of the next level.

Replacement of the fuse

Currently, due to the relatively troublesome maintenance of fuses, the replacement of the fuse element and fuse tube must be carried out without power to avoid accidents caused by electric arcs. The fuse element must be replaced according to the original specifications and materials. It is not allowed to replace the fuse element with a different rated current.

Many people use circuit breakers instead of fuses, which is actually not very good for some occasions where the current is particularly large and rapid protection is needed. Fuses have advantages in terms of effectiveness and cost-effectiveness. Regarding safety, everyone must not neglect it and treat it with caution.