Single-phase three-wire neutral wire open-phase protection with earth leakage breaker

摘要

(57) [summary] [purpose] neutral wire open-phase detection for Li - de lines even when disconnected you can cause a connection off, detects the connection cut-off state, It was able to block the main contact and an object thereof is to enable a reliable phase loss protection. [Configuration] comparator the abnormal voltage detecting circuit AV - a motor 2A is provided, its comparator - while connecting the inverting input terminal of the motor 2A to the point A, to the non-inverting input terminal by applying a reference voltage VL is close to zero volts , neutral wire open-phase detection for Li - when the lead wire 3 is smaller than the voltage reference voltage VL of point A Become a connection cut-off state, such as or, or disconnected caused the connection off, comparator - from other 2A configuring a connection cutoff detection circuit CA so as to output a signal of logic "H". Thus is energized trip coil 7 for the thyristor 8 two-point ignition signal from the output circuit 6 from the connection cutoff detection circuit CA and signal of logic "H" is output is output, the main contact is cut off.