Insulating material surface leakage current detecting for tool, for use on electric power network, involves activating alarm signal of fault and risk of usage of tool when measured current exceeds threshold value

摘要

The method involves deriving a measured current (Im) from a leakage current (If), and comparing the derived measured current with a threshold value. An alarm signal of fault and risk of usage of a tool is activated when the derived measured current exceeds the threshold value. The alarm signal is not activated when the measured current does not exceed the threshold value. An independent claim is also included for a device for detecting a leakage current of a surface on an insulating material constitutive of a tool unit.