Model A leakage circuit breaker
Type A and Type AC leak circuit breakers are basically the same in their working principle (measuring the leakage value through the zero-sequence current transformer), but the magnetic characteristics of the transformer are improved.It ensures tripping under the following conditions:
(A) Same as AC type.
(b) Residual pulsating DC current.
(c) Remaining pulsating DC current superimposed with A smooth DC current of 0.006A.
Type B leakage circuit breaker --(more difficult to do)
B type leakage circuit breaker can reliably protect sinusoidal AC signal, pulsating DC signal and smooth signal, and has higher design requirements than A type leakage circuit breaker.It ensures tripping under the following conditions:
A) Same as type A.
B) Residual sinusoidal alternating current up to 1000Hz.
C) Surplus AC current with a smooth DC current of 0.4 times the rated residual current
D) Remaining pulsating DC current superposition 0.4 times rated residual current or 10mA smooth DC current (whichever is greater)
E) Residual DC current generated by the following rectifying lines:
-- For 2 -, 3 -, and 4 - pole leakage circuit breakers, two half - wave bridge connections of wire to wire.
-- For 3 - and 4-pole leakage circuit breakers, 3 half - wave star connections or 6 half - wave bridge connections.
Various types of residual current circuit breaker can effectively protect the corresponding leakage signal, contains A lot of devices and circuits of frequency conversion equipment, because the pulsating dc signal is contained in the leakage signal, AC type residual current circuit breaker can not effectively protect the circuit, then you should choose for pulsating dc signal leakage circuit breaker - type A residual current circuit breaker.
