INVESTIGATIONS ON THE INFLUENCE OF CURRENT INTERRUPTION OPERATIONS ON THE ON-SITE MEASUREMENT OF THE INTERNAL PRESSURE IN VACUUM INTERRUPTERS

From various pressure measuring principles, only the magnetron method, using a vacuum interrupter (VI) as its own gauge, was identified in previous investigations to be suited for a quantitative on-site assessment of the vacuum inside a sealed VI. The application of this pressure measuring principle, however, requires a disconnection of the vacuum circuit breaker (VCB) and thus, an electrical switching operation, influencing the internal pressure and the residual gas composition inside the VI. Due to the impact of the arcing on the high purity surfaces and the bound residual gases, the pressure measured after disconnecting the VCB can be different from the initial pressure before the VCB has been disconnected. Hence, the influence of current interruption operations on the internal pressure…