It is suitable for alarm the operator of the aerial device when the boom or platform or bucket crosses the live working zone of the live line system. The environment of detecting always depends on where the detector is placed. The warning signals of detector are high power siren sound and/or caution light. Option, that blocks the move of controled aerial device by output of a relay. On-demand more sensors can be placed on different points of the aerial device (L2 and L5), in addition user can choose four detecting voltage level by the built-on switch (L2 – L5).