35KV high-voltage fuse for wind farm

35KV high-voltage fuse for wind farmProduct advantages: This product is designed to meet technical standards and has innovative and practical functions.

The product uses synthetic silicone rubber material as the insulator, and the central material uses an insulating pull rod.

The switch contacts are made of steel, phosphor bronze material, and stainless steel material.

All connecting parts are made of stainless steel standard parts (304 material).

The switch action part consists of die cast copper parts and fiberglass wrapped tubes.

The upper moving contact of the melting tube is designed as a double contact combination, and the lower moving contact is designed as a flip contact.

The static contact on this product is a double contact surface, with a pressure contact method at and a card and contact method at.

The lower static contact is a copper die-casting contact.

3. Working principle

Drop out fuseIt consists of three parts: insulator, contact conductive system, and melting tube. During normal operation, the fuse locks the movable joint on the melting tube, and the melting 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 melting tube. The arc extinguishing tube lining the melting tube decomposes a large amount of gas under the action of the arc, which produces a strong dissociation effect when the current crosses zero and extinguishes the arc. Due to the melting of the fuse, the release of the movable joint causes the melting tube to sag, rapidly falling under the elastic force of the upper and lower contacts and the weight of the melting tube, forming a clear disconnect gap.

4.Selection of fuses

The short-circuit capacity of the installation location should be withinDrop out fuseWithin the rated breaking capacity range. If the upper limit is exceeded, the molten tube may explode due to excessive current and gas production; If it is below the lower limit, it is possible that the arc cannot be extinguished due to insufficient current and insufficient gas production. Therefore, when selecting the rated capacity of a drop out fuse, it is necessary to consider not only matching its upper limit breaking current with the maximum short-circuit current at the installation location, but also paying attention to the relationship between its lower limit breaking capacity and the minimum short-circuit current at the installation location. Considering that the drop type high-voltage fuse serves as the main protection for internal faults in distribution transformers, with a protection range from the low-voltage fuse transformer side to the high-voltage fuse transformer side, and also serves as a backup protection for low-voltage fuses, its lower limit breaking capacity should be selected based on the minimum short-circuit current of the low-voltage outlet two-phase short circuit.

5.Selection of fuses

The selection of fuses should ensure that they can quickly melt in the event of a short circuit inside the distribution transformer or in the high and low voltage outgoing bushings. In practice, the following principles are often followed for selection: the capacity of the distribution transformer is160kVAThe fuse is based on the rated current of the transformer2～3Choose twice; The capacity of the distribution transformer is160kVAAbove, press1.5～2Multiple choices. The selection of fuses must also consider whether the melting characteristics of the fuse can match the superior protection time, which is the key issue in determining whether fuse protection can be effective. The quick break protection action time of the distribution line is very short, about0.1sabout. According to the characteristic curve of the fuse, in0.1sThe current that causes the fuse to melt inside should not be less than the rated current20Twice. This data is a necessary condition to ensure the coordination between the fuse and the head end circuit breaker.

6.Installation of drop out fuses

(1)During installation, the melt should be tightened tightly(Make the melt approximately subjected to24.5NLeft and right tension)Otherwise, it is easy to cause the contact to heat up.

(2)The fuse is installed on the crossbar(framework)The upper part should be firm and reliable, without any shaking or shaking phenomenon.

(3)The melting tube should be downward25°±2°The inclination angle is designed to facilitate the rapid drop of the melt tube by its own weight when the melt melts.

(4)The fuse should be installed at a vertical distance from the ground of not less than4mThe crossbar(framework)If installed above the distribution transformer, it should be kept in line with the outer contour boundary of the transformer0.5mThe above horizontal distance is in case the melting tube falls and causes other accidents.

(5)The length of the melting tube should be adjusted appropriately, and it is required that the duckbill tongue can hold more than two-thirds of the length of the contact after closing to avoid accidental dropping during operation. The melting tube should not be pushed to the death of the duckbill to prevent the melting tube from falling in time after melting.

(6)The melt used must be a standard product from a legitimate manufacturer and have a certain mechanical strength. Generally, the melt is required to be able to withstand as little as possible147NThe above tension.35KV high-voltage fuse for wind farm

(7) 10kVDrop out fuses are installed outdoors, requiring a phase to phase distance greater than70cm.

7.Operation, maintenance and management of fuses

(1)Whether the rated current of the fuse device matches the current value of the fuse link and load appropriately, and if not, adjustments must be made.

(2)Each operation of the fuse must be careful and meticulous, and must not be careless, especially during the closing operation, which must ensure good contact between the moving and stationary contacts.

(3)It is advisable to avoid using drop out fuses to disconnect the rated breaking capacity multiple times in a row. For fuses with steel paper tubes on the inner wall of the fuse tube, the rated breaking capacity should not be disconnected more than three times in a row.

(4)The standard melt produced by a legitimate manufacturer must be used inside the melting tube. Copper wire and aluminum wire are prohibited from replacing the fuse link, and copper wire, aluminum wire, and iron wire are not allowed to be used to tie the contact.

(5)For newly installed or replaced fuses, strict inspection procedures must be carried out and they must meet the quality requirements of the regulations.

(6)After the fuse is blown, it should be replaced with a new melt of the same specification. It is not allowed to connect the melted melt and then install it into the melting tube for continued use.

(7)The fuse should be checked regularly, at least once a month at night, for any discharge sparks or poor contact. If it does not discharge, there will be a hissing sound, and it should be arranged for early treatment

Its structure generally includes fuse tubes, contact conductive parts, supporting insulators, and bases. Metal wires or sheets made of metal materials with lower melting points are connected in series in the protected circuit. When the circuit or equipment in the circuit is overloaded or malfunctions, the fuse heats up and melts, thereby cutting off the circuit and achieving the purpose of protecting the circuit or equipment.