To provide an earth leakage detector capable of improving detecting accuracy of earth leakage as well as reducing a cost of the device as a whole and excellent in assembling easiness.
A zero-phase current transformer 24 of the earth leakage detector is formed of an oval-shaped core, and has a structure where, through a through-hole of the core, a plurality of primary conductors 55R, 55S, 55T each formed in straight line are inserted in a state of being disposed in parallel. Current detectors 21, 22, 23 are provided on a circuit board 56 through which the primary conductors 55R, 55S, 55T penetrate, the current detectors corresponding the primary conductors, respectively. A correction operation processing circuit 33 carries out correction operation processing on an output value of the zero-phase current transformer 24 in accordance with the outputs of the current detectors 21-23 and an unnecessary output component is removed. An earth leakage current determination part 34 compares an output of the correction operation processing circuit 33 with a predetermined value and determines whether or not it is in a state of earth leakage and outputs an earth leakage detecting signal to an output terminal 35.
SHIOKAWA AKIMI
YAMAZOE KOICHI
| JPH10261358A | 1998-09-29 | |||
| JP2004095222A | 2004-03-25 | |||
| JP2000228323A | 2000-08-15 |
Toshimitsu Ichikawa
Kimihide Hashimoto