Capacitor Protection Drop-out Fuse
Capacitor protection cover drop out fuse
It is mainly used for single overcurrent protection of high-voltage parallel capacitors in power systems, that is, it is used to cut off faulty capacitors to ensure the normal operation of fault-free capacitors.
Spray type drop fuse: single protection of parallel capacitors drop fuse cutout.
Working principle
The drop out expulsion fuse is composed of an external arc extinguishing tube, an internal arc extinguishing tube, a fuse and a tail line ejection device. Among them, the external arc extinguishing tube is composed of epoxy glass fiber cloth tube and anti-white steel paper tube, which mainly plays the role of insulation, explosion resistance and effective interruption of rated capacitive current;
The internal arc extinguishing tube can gather non-combustible gas with sufficient pressure at the moment of interruption to improve the interruption capacity, so it is used to interrupt small capacitive current. The tail line ejection device is divided into an external spring type and an anti-swing type structure according to different application conditions. The anti-swing type structure is divided into two forms according to the different placement forms of the matching capacitors, which are suitable for upright placement of capacitors and horizontal placement of capacitors.
The external spring type uses a stainless steel spring as the tension spring of the drop out fuse 22kv fuse. When the drop out fuse 33kv works normally, the spring is in a tensioned energy storage state. When the fuse is overcurrent and blown, the spring releases energy, so that the residual tail of the fuse is quickly pulled out of the external arc-extinguishing tube, and the gas generated by the internal and external arc-extinguishing tubes extinguishes the arc when the current passes through zero, ensuring that the faulty capacitor is reliably disconnected from the system.
This structure is generally used in frame-type capacitor sets. The anti-swing structure is to change the external spring into an internal tension spring structure with an insulating anti-swing tube, that is, the spring is built into the anti-swing tube, and the fuse is connected to the capacitor terminal after being tightened and fixed by the tension spring.
When the fuse is overcurrent and blown, the energy of the tension spring that has been stored is released, and the residual tail is quickly pulled into the anti-swing tube. At the same time, the anti-swing tube moves outward under the action of the auxiliary torsion spring at the fixed point, which also promotes the rapid expansion of the fracture, ensuring the reliable breaking of drop out fuse cut out. The anti-sway pipe prevents the residual tail wire from colliding with the capacitor network door and cabinet door, eliminating safety hazards.
