What Are The Reasons For The Decrease In Vacuum Degree Of Outdoor High-voltage Vacuum Circuit Breakers?

Lv Pole Mounted Circuit Breakers plays an important role in the power grid. Due to its excellent performance, it has continuously replaced other circuit breakers. Then, during long-term use, the vacuum degree will decrease. What are the reasons for this situation?

First, the impact of the buffer. The buffer stroke should be carefully checked. There should be no deformation damage or excessive compression, and a buffer margin must be left. Some oil-filled buffers should check the buffer oil level regularly and replenish oil in time.

Second, the impact of bounce. The contacts of vacuum circuit breakers are mostly flat docking structures, and different degrees of rebound are inevitable during the opening and closing operations. Whether it is the rebound of the opening or the rebound of the closing, it will cause harm to the operation: the bellows may crack due to forced vibration, causing the arc extinguishing chamber to leak; the movement speed of the circuit breaker contacts is high during the opening and closing, and the impact force is large at the end of the action, causing bounce, which may cause deformation of the contacts and the conductive rod, and even cracks; if the vacuum circuit breaker that cuts the capacitor group bounces after closing, it will also cause damage to the capacitor.

Third. The influence of the opening and closing speed The opening and closing speed of the circuit breaker plays a certain role in the arc extinguishing of the vacuum circuit breaker and also determines the service life of the vacuum circuit breaker. Therefore, the opening and closing speed of the circuit breaker should be measured before commissioning, so that some problems in product quality and debugging can be discovered in time. On the one hand, it is prevented that the opening and closing speed is too large, and the mechanical collision is fierce when the circuit breaker contacts are terminated, causing more serious vibration in the arc extinguishing chamber.

Fourth. The influence of contact stroke At present, the various types of 10kv vacuum circuit breaker arc extinguishing chambers produced in China have contact overtravel of about 4mm and opening distance of about 11mm according to regulations. When installing or overhauling the vacuum circuit breaker, the contact stroke requirements in the product installation manual should be strictly measured and the pull rod should be adjusted to prevent the stroke from exceeding. In addition, the stroke, overtravel and contact opening distance of the vacuum circuit breaker should be carefully reviewed during the annual overhaul. In actual operation, there are many accidents in which the arc extinguishing chamber is broken and the conductive rod is deformed due to improper adjustment of the circuit breaker overtravel, resulting in mechanical impact during the closing process of the circuit breaker. Therefore, the reasons for the decrease in vacuum degree of outdoor high-voltage vacuum circuit breakers are often caused by the above-mentioned points, so we must regularly inspect and maintain them.