(1) Spiral fuse RL:
Fuse: The fuse in the fuse tube is equipped with quartz sand, and the melt is buried in it. When the melt melts, the arc is sprayed towards the quartz sand and its gaps, which can quickly cool down and extinguish it. In order to facilitate monitoring, one end of the fuse is equipped with a color dot. Different colors represent different melt currents. When the melt melts, the color dot pops out to indicate that the melt has melted. Screw-type fuses have a rated current of 5 to 200A and are mainly used in branch circuits with large short-circuit currents or in places with flammable gases.
(2) With stuffing tube fuse RT:
A stuffed tube fuse is a fuse with a current limiting effect. It consists of a porcelain fusion tube filled with quartz sand, contacts and silver-plated copper grid fusion. Stuffing tube fuses are installed on a special base, such as a base with an isolation knife or a base with the fuse as an isolation knife, and are operated by a manual mechanism. Stuffing tube fuses have a rated current of 50 to 1000A and are mainly used in circuits with large short-circuit currents or places with flammable gases.
(3) Packingless tube fuse RM:
The fuse tube of unfilled tube fuses is made of fiber material. The melt used is zinc alloy sheet with variable cross-section. When the melt melts, part of the fiber material in the fiber fusion tube is decomposed by heat, producing high-pressure gas, which quickly extinguishes the arc. Filler-free tube fuses have the characteristics of simple structure, good protection performance, and easy use. They are generally used in combination with a knife switch to form a fuse-knife switch.
(4) Packing-sealed tubular quick-blow fuse RS:
The stuffed closed tube fast-acting fuse is a fast-acting fuse, which consists of a fuse tube, a contact base, an action indicator and a melt. The melt is in the form of silver narrow section or mesh. The melt is for one-time use and cannot be replaced by yourself. Due to its fast action, it is generally used to protect semiconductor rectifier components.
(5) fuse
Drop-out fuses can be divided into high-voltage fuses and low-voltage fuses according to the voltage used. According to the protection objects, they can be divided into fuses for protecting transformers and general electrical equipment, fuses for protecting voltage transformers, fuses for protecting power capacitors, fuses for protecting semiconductor components, fuses for protecting motors and fuses for protecting household appliances. Fuses, etc. According to the structure, it can be divided into open, semi-enclosed, tube and spray fuses.
(6) The open fuse has a simple structure, the melt is completely exposed to the air, and is supported by a porcelain column. There is no support, and it is suitable for low-voltage outdoor use. When the current is broken, a loud sound and light are produced in the atmosphere.
(7) The melt of the semi-enclosed fuse is mounted on a porcelain frame and inserted into a porcelain box with metal sockets at both ends. It is suitable for low-voltage indoor use. When the current is broken, the sound and light generated are blocked by the porcelain box.
(8) The melt of the tubular fuse is installed in the fuse body. Then plug it into the holder or connect it directly to the circuit for use. The fuse link is a completely sealed insulating tube with metal caps or contact blades on both ends. If the insulating tube of this fuse is filled with quartz sand, it will have a current limiting effect when breaking the current, which can greatly improve the breaking capacity, so it is also called a high breaking capacity fuse. If a vacuum is drawn inside the tube, it is called a vacuum fuse. If the tube is filled with SF6 gas, it is called an SF6 fuse, and its purpose is to improve arc extinguishing performance. Since quartz sand, vacuum and SF6 gas all have good insulation properties, this fuse is suitable for not only low voltage but also high voltage.
(9) Injection fuses contain the melt in an insulating tube made of solid gas-generating material. Solid gas-generating materials can be electrically inverted white cardboard or organic glass materials. When the short-circuit current passes through the melt, the melt immediately melts and generates an arc. The high-temperature arc causes the solid gas-producing material to rapidly decompose to produce a large amount of high-pressure gas, thereby ejecting the ionized gas with the arc at both ends of the tube, emitting great sound and light. And when the AC current crosses zero, the arc is extinguished and the current is interrupted. The insulating tube is usually mounted on an insulating bracket to form the entire fuse. Sometimes the upper end of the insulating tube is made movable, and it detaches and falls after breaking the current. This type of spray fuse is commonly known as a drop fuse. Generally suitable for outdoor occasions with voltages higher than 6 kV.
In addition, fuses can also be divided into general-purpose fuses, backup fuses and full-range fuses according to the breaking current range. The breaking current range of general-purpose fuses refers to the range from the overload current greater than 1.6 to 2 times the rated current to the maximum breaking current. This type of fuse is mainly used to protect power transformers and general electrical equipment. The breaking current range of the backup fuse refers to the range from the overload current greater than 4 to 7 times the rated current to the maximum breaking current. This kind of fuse is often used in series with a contactor. When the overload current is less than 4 to 7 times the rated current, the contactor implements breaking protection. Mainly used to protect the motor.
