Behaviour of outdoor vacuum circuit breakers under simulated environments

Outdoor vacuum circuit breaker are the most commonly used switchgear in the Medium High Voltage(MHV) segment particularly in the 11 kV and 33 kV distribution grids. As these breakers are used in outdoor switchyards they are exposed to varied weather conditions. A study was undertaken to ascertain the performance of outdoor Vacuum Circuit Breaker (VCB) under simulated low and high ambient conditions which are presented in this paper. The results of this study have been analyzed to understand the performance of the MHV Outdoor VCBs under various low and high ambient conditions. Important conclusions derived from the study have been discussed in the paper.