SAFETY DEVICE FOR ELECTRICAL DEVICE

To provide a safety device for an electrical device that operates based on measurement values of a voltage measuring device, and can operate in response to a voltage in the electrical device even when a large voltage is applied to the electrical device as in an insulation resistance test.SOLUTION: A safety device 1 for an electrical device includes: a P-phase voltage dividing circuit 32 that divides a voltage between a P-phase potential supplied to a specimen 3 and a ground potential; a P-phase voltage measuring device 33 that measures a divided voltage obtained by the P-phase voltage dividing circuit 32; a safety mechanism 10 having a lock unit; and a safety mechanism control unit 20 that outputs a lock release signal to the safety mechanism 10 when the voltage measured by the P-phase voltage measuring device 33 is less than a predetermined value. The P-phase voltage dividing circuit 32 includes a plurality of resistors 32a connected in series so that the divided voltage obtained when the maximum voltage is applied to the specimen 3 is equal to or less than the withstand voltage of the P-phase voltage measuring device 33.SELECTED DRAWING: Figure 2 【課題】電圧計測装置の計測値に基づいて動作する電気機器用安全装置において、絶縁抵抗試験のように電気機器に大きい電圧が印加された場合でも、前記電気機器内の電圧に応じて動作可能な電気機器用安全装置を提供する。【解決手段】電気機器用安全装置１は、供試体３に供給されるＰ相の電位と接地電位との間の電圧を分圧するＰ相分圧回路３２と、Ｐ相分圧回路３２で得られる分圧を計測するＰ相電圧計測装置３３と、ロック部を有する安全機構１０と、Ｐ相電圧計測装置３３によって計測された電圧が所定値未満の場合に、安全機構１０に対してロック解除信号を出力する安全機構制御部２０と、を備える。Ｐ相分圧回路３２は、供試体３に最大電圧が印加された際に得られる分圧がＰ相電圧計測装置３３の耐電圧以下になるように、直列に接続された複数の抵抗３２ａを有する。【選択図】図２