Electricity distribution transformer protection - improved thermal circuit breaker using separate isolating transformer

摘要

A method of improving the performance of thermally operated circuit breakes located in the windings of electricity supply transformers, reduces the effect of over-voltages which occur especially with overhead lines. A separate isolating transformer is used with primary fed from the distribution transformer instead of the conventional method of connection the circuit breaker directly to the low voltage supply. Advantageous application is offered with thermostatic encapsulated circuit breakers.