What causes air leakage in the arc extinguishing chamber of VS1 vacuum circuit breaker?

The vacuum interrupter (vacuum tube) of the vs1 vacuum circuit breaker is an important component of the vacuum circuit breaker. It can be said that it is the soul of the vacuum circuit breaker. Since the vacuum interrupter is composed of ceramics or glass, if it is once vacuumed during use If the ceramic or glass of the arc extinguishing chamber is broken, or there are cracks, it can cause air leakage in the vacuum arc extinguishing chamber. If there is air leakage, serious consequences will occur, so protecting the vacuum arc extinguishing chamber has become a top priority. This is also It is related to the stability and safety of the entire vacuum circuit breaker operation and the life of the vacuum circuit breaker. So what do we need to pay attention to during use and assembly of vacuum circuit breakers to prevent air leakage in the vacuum interrupter? What parameters will affect the leakage of vacuum breaker? Let’s take a look below

The contacts of VS1 vacuum circuit breaker are mostly flat butt-type structures, which inevitably produce varying degrees of rebound during the opening and closing operations. to

Both opening rebound and closing rebound will bring harm to the operation: the corrugated pipe may produce cracks when subjected to forced vibration, causing air leakage in the arc extinguishing chamber; the circuit breaker contacts move at a high speed during opening and closing, and the impact force at the end of the action is relatively high. If the circuit breaker is too large, it will bounce, which may cause deformation of the contacts and conductive rods, or even cracks; if the vacuum circuit breaker that is connected to the capacitor bank bounces on closing, it will also cause damage to the capacitor.

Therefore, some vacuum circuit breaker manufacturers have now noticed the harm caused by the bounce of vacuum circuit breakers, and have introduced so-called "bounce-free" vacuum circuit breakers. Through mechanical buffering and other means, the mechanical impact generated by the circuit breaker during opening and closing is greatly reduced. .

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. For some oil-filled buffers, the oil level of the buffer should be checked regularly and the oil should be replenished in time.

The influence of contact stroke

At present, the contact overtravel of various types of 10kv vacuum circuit breaker arc extinguishing chambers produced in China is about 4mm according to regulations, and the opening distance is about 11mm. When installing or repairing a vacuum circuit breaker, the contact stroke requirements in the product installation instructions should be strictly followed to accurately measure and adjust the tie rod to prevent the stroke from being exceeded. In addition, during the annual overhaul of the vacuum circuit breaker, the stroke and overshoot of the circuit breaker should be carefully reviewed. Stroke and contact opening distance. Content comes from: China Electronics Exhibition Network

In actual operation, there are many accidents due to improper adjustment of circuit breaker overtravel, resulting in mechanical impact during the closing process of the circuit breaker, causing arc extinguishing chamber rupture and conductive rod deformation.

The influence of operating mechanism capacity

The common operating mechanisms of vacuum circuit breakers mainly include CDlO type, CDl7 type, VSl type, and operating mechanisms modified to adapt to different installation spaces based on the above models. In recent years, some domestic circuit breakers are equipped with " Permanent magnet operating mechanism".

Different types of operating mechanisms are configured. When installing or modifying, attention should be paid to the operating distance of the operating transmission rod. If the capacity is too large, it will cause serious impact on the arc extinguishing chamber, causing damage to the bellows of the vacuum arc extinguishing chamber, and directly affecting the vacuum. The service life of the circuit breaker accelerates the reduction of the vacuum degree of the circuit breaker.

Influence of 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 it is put into operation, 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 high, and the mechanical collision is violent when the circuit breaker contacts end, causing more serious vibrations in the arc extinguishing chamber.

To sum up, the vacuum circuit breaker is related to the above parameters, so we must strictly control these parameters during the process of assembling the vacuum circuit breaker.