METHOD FOR DETERMINING RESIDUAL LIFE OF AUTOMATIC CIRCUIT BREAKERS Russian patent published in 2015 - IPC G01R31/327 

FIELD: measurement equipment.

SUBSTANCE: method for determining residual life of automatic circuit breakers in electrical installations provides for measurement and storage of current value i_j that caused actuation of the circuit breaker at each j deactivation, where j=1, …, n, and calculation of coefficient k₁(i_j) characterising allowable number of actuations depending on the switched current i_j, and additionally, it provides for continuous measurement of current i passing through the automatic circuit breaker. And residual life of the automatic circuit breaker is determined by the formula: $$T(t)=T_0-{\displaystyle \sum _{j=1}^n{k}_1(i_j)-k_2{\displaystyle \underset{0}{\overset{t}{\int }}{i}^{2}dt}},$$ where T₀ - service life of an automatic circuit breaker; k₂ - weight coefficient equal to design coefficient of life wear of the automatic circuit breaker, n - total number of actuations of the automatic circuit breaker from the beginning of operation, t - full time of operation of the automatic circuit breaker.

EFFECT: providing high-accuracy continuous assessment of residual life of a circuit breaker considering its reduction due to passage of operating currents.

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