EARTH LEAKAGE MONITORING DEVICE

• Main Authors: YAMADA TOMOHIRO, GOTO SHINICHIRO, YOKOTA KOJI
• Format: Patent
• Language: English; Japanese
• Published: 17.09.2020
• Subjects: ALARM SYSTEMS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; ORDER TELEGRAPHS; PHYSICS; SIGNALLING; SIGNALLING OR CALLING SYSTEMS; TESTING

To aim at gaining both of a planned maintenance activity when earth leakage is increasing gradually and prompt recovery when abrupt earth leakage occurs without using an ELCB for each individual apparatus.SOLUTION: An earth leakage monitoring unit 20 includes: detection parts (205, 206, 207, 208) of a leakage current output from a zero-phase current transformer 13; a processing part 209 for calculating an instantaneous value of a leakage current at a period equivalent to or more than operation of an earth leakage circuit breaker 11 on the basis of output of the detection parts and performs abnormality determination when the instantaneous value exceeds a threshold; a display part 203 for displaying the instantaneous value and a result of abnormality determination on the basis of output of the processing part 209; and a power supply circuit 204 capable of supplying an output voltage during a predetermined period even if an input voltage is lost. The display part 203 maintains display even after supply of the output voltage by the power supply circuit 204 is stopped.SELECTED DRAWING: Figure 2 【課題】個別の機器ごとにELCBを用いることなく、徐々に漏電が増加している場合の計画的な保全活動と、突発的な漏電発生時の早期復旧とを両立すること。【解決手段】漏電監視ユニット２０において、零相変流器１３から出力される漏洩電流の検出部（２０５，２０６，２０７，２０８）と、検出部の出力に基づき、漏電遮断器１１の動作と同等以上の周期で漏洩電流の瞬時値を算出し、瞬時値が閾値超えた場合に異常判定を行う処理部２０９と、処理部２０９の出力に基づき、瞬時値および異常判定の結果を表示する表示部２０３と、入力電圧が消失しても所定期間において出力電圧の供給が可能な電源回路２０４と、を備え、表示部２０３は、電源回路２０４による出力電圧の供給が停止した後においても表示を維持する。【選択図】図２