Arching contacts is a general electrical component, which is usually used in conjunction with the main contact. Arching contacts' main application is interrupter, when first turned on closing, sub-gate when disconnected.
When the circuit breaker off: first disconnect the main contact; after arc interruption contacts.
When the circuit breaker is closed: the first arc contact is closed after the main contacts are closed.
When the switch is closed, the closing of the electric arc contact bear wear; switch sub-gate, bear strong arc contact arcing circuit breaking time, the protective role of the main contact; long-term commitment by the main contact load current task. So in the closing arc contact closes before the main contacts after closing; when opening the main contacts first disconnect after the arc contacts are open. Main contact resistance is usually smaller than the arc contact resistance.
SF6 Circuit Breaker Closing On the Arc Contacts
Off SF6 circuit breaker closing operations generated combined surge of arcing contacts can cause serious erosion. In closing test arc contact erosion has two sources: one is closing before the expected breakdown arc ablation, a mechanical wear after ablation arc contact softened, and accounts for a considerable mechanical wear the ratio can not be ignored. With the construction of UHV AC transmission steadily, research UHV power transmission technology is increasingly fruitful. UHV charging power, with the change of system operation mode, power flow in a wide range, thus UHV transmission system was reactive break-even more substantial changes, the need for adequate reactive power regulation means, wherein the main transformer three sides by UHV substation automatic switching capacitor is an important means to regulate reactive power regulation.
CuW80 Arc Contact Test
Through various tests available CuW80 arc contact at a current 20kA arcing time 9ms was mass loss rate of about 0.6mg / C, arcing time and made smaller, the smaller the mass loss rate. The closing of the contact erosion do research, but mainly concentrated in the low-voltage contactors, high-voltage SF6 circuit breakers for the process of closing the contact erosion characteristic little research, but also SF6 circuit breaker contacts during closing mass erosion rates have been reported. Due to the different closing process and breaking process, SF6 circuit breaker closing contacts in case of attack will exhibit many of the circumstances under breaking inconsistencies, it will be different on the corrosion mechanism.