The drop type fuse is the most commonly used short-circuit protection switch for branch lines and distribution transformers of 72.5kV and below distribution lines. It has the characteristics of economy, easy operation, and strong adaptability to outdoor environments. It is widely used for protection and equipment switching operations on the primary side of distribution lines and transformers of 72.5kV and below. It is installed on the branch lines of distribution lines with a voltage of 72.5kV and below, which can reduce the power outage range. Due to its obvious disconnection point, it has the function of an isolation switch, creating a safe working environment for the maintenance section lines and equipment, and increasing the sense of safety for maintenance personnel. Installed on distribution transformers, it can serve as the main protection for distribution transformers, so it has been widely used in distribution lines and transformers with a voltage of 72.5kV and below.
The drop type fuse consists of three parts: insulator, contact conductive system, and fuse tube. During normal operation, the fuse locks the movable joints on the fuse tube, and the fuse tube is in a closed state under the pressure of the upper contact. When a fault occurs, the fuse melts and an arc is generated inside the fuse tube. The arc extinguishing tube inside the fuse tube decomposes a large amount of gas under the action of the arc, producing a strong deionization effect when the current crosses zero and extinguishing the arc. Due to the melting of the fuse, the release of the movable joint causes the fuse tube to sag, rapidly falling under the elastic force of the upper and lower contacts and the weight of the fuse tube, forming a clear gap for disconnection.
Main features:
1. Windproof design, sturdy structure, able to withstand 30m/s wind speed, avoiding frequent self detachment
The 2 products use porcelain jackets or silicone rubber materials as insulators, and the center material uses glass wire insulation pull rods
The 3 switch contacts are made of steel, phosphorus bronze material, and stainless steel material
4. All connecting standard parts are made of stainless steel 304 material standard parts
The 5 switch action parts are die-casting copper parts and fiberglass wrapped tubes
The design method for the upper moving contact of the 6-melt tube is a combination of double contacts, and the lower moving contact is a flipped contact
The upper static contact of the 7 products has a dual contact surface, with the first contact being a pressure contact method, the second contact being a card and contact method, and the lower static contact being a copper die-casting contact
8 fuses with unique reflective yellow markings at night, making it easy to quickly locate faults at night
