Abstract
In this study, the condition of high-voltage three-phase
SF6 circuit breakers is assessed using analysis of variancebased
statistical test. 40 sulphur hexafluoride (SF6) circuit
breakers, with similar technical characteristics and
operating conditions, were tested on the field using the
SA10 switch analyser. The chi-square test for normality
was performed on the measured coil tripping times, before
analysis of variance was applied. Results obtained indicate
the difference between and within the coil tripping times
is not significant.