Optimal controlling of the interruption of high short circuit currents with a monophase vacuum interrupter

The advantage of the optimal control of the interruption of high short circuit currents with a monophase vacuum interrupter is presented. The investigation has proved that the contact opening moment of the vacuum tube has a great influence upon the state of the vacuum arc and by this upon the interrupting capability of the vacuum interrupter. Based on the method with which the contacts are controlled definitely to open with a suitable spring operating device, one can ensure a diffuse arc during the interruption of high short circuit currents, which minimizes the amount of burn-off of the contacts. The interrupting capability and the lifespan of the vacuum interrupter can be enhanced essentially.