Insulating enclosed type pagoda-shaped fuse

Abstract

The invention relates to an insulating enclosed type pagoda-shaped fuse (1), which comprises upper and lower lead-out wires (6 and 7), upper and lower chambers (8 and 9) in the fuse, upper and lower fixed contacts (11 and 22), an arc extinction cylinder (15) and a fuse carrier (28) inserted into the arc extinction cylinder; the opening position at the lower end of an insulator body is fixed with a lower cover (24); the lower cover (24) is detachably provided with a cover body (26) of a penetrating pressure releasing hole (25); and the surface leakage distance of the fuse is more than 350mm. The insulating enclosed type pagoda-shaped fuse can instantly discharge high-pressure gas instantly generated through the pressure releasing hole to relieve the damage to components in the fuse; and in addition, the power frequency withstand voltage of the fuse is higher (dry flashover is between 42 and 48kV, and wet flashover is 30kV), the breaking performance of 12kV reaches Sym. 8kA, and the safety performance of the hot-line work is improved.

Description

technical field [0001] The present invention relates to a high-voltage fuse, in particular, the present invention relates to an insulated closed pagoda-shaped fuse equipped with a fuse-carrying part for transformer or distribution line protection. The insulating closed pagoda fuse of the present invention is especially suitable for the protection of transformers or distribution lines of power distribution systems of 10kV and above. Background technique [0002] In the past, drop-out fuses were often used to protect transformers or distribution lines. [0003] Drop-out fuses with load (hereinafter referred to as fuses) are suitable for distribution lines and distribution transformers with rated voltage 10kV, rated current below 200A, and frequency 50Hz, as overload and short circuit protection, and for breaking and closing rated load current. [0004] Its product features: The fuse is composed of two parts: the base and the arc suppression device. When the fuse is in the cl...

AI Technical Summary

Problems solved by technology

[0006] (1) The product process is rough, the manufacturing quality is poor, and the contact spring is not elastic enough, resulting in poor contact of the contact and spark overheating

[0007] (2) The roughness and inflexibility of the rotating shaft of the melting tube make the angle of the melting tube fail to meet the requirements of the regulations, especially the size of most of the equipped melting tubes does not meet the requirements of the regulations. After the fuse is blown, the fuse tube cannot fall quickly, and the arc is cut off and extinguished in time, causing the fuse tube to burn or explode; the size of the fuse tube is short, it is difficult to close the switch, the contact is not in good contact, an electric spark is generated, or an electric shock occurs

According to its ability to interrupt capacity, it is not difficult to see that the arc cannot be extinguished in time after the melt is blown during a short-circuit fault, and it is easy to burn or explode the fuse tube.

[0009] (4) The size of the fuse tube of some new switches does not match the size of the fixed contact part of the fuse. power, and it is difficult to guarantee the power supply reliability index

If the above problems are not solved, the electric field will be concentrated between the installation fittings and the fuse-carrying parts, resulting in corona discharge phenomenon

[0017] In addition, in the past, although the lower cover (24) and its cover (26) were fixed at the lower opening of the insulator body, because there was no pressure relief hole, the instantaneously generated high-pressure gas could not be released through the pressure relief hole at the moment of fusing. This will lead to damage to the components in the fuse and affect its service life

[0018] Furthermore, in the past, the surface leakage distance of the fuse was usually between 220-275mm, resulting in a low power frequency withstand voltage and a decrease in the safety of live work

At the same time, the overall height of the previous insulation-enclosed fuses is mostly about 400-425mm, which makes it impossible to achieve sufficient surface leakage distance on the usual fuses with ribbed shed structures, making their power frequency withstand voltage lower.

In addition, the length of the fuse element (melt) is mostly about 200-245mm, resulting in a decrease in the safety of live work

[0019] make its withstand voltage limited

Images