An insulation monitoring device monitors the ungrounded system between an active phase conductor and earth. It is intended to give an alert(light and sound) or disconect the power supply when the impedance between the two conductors drops below a set value, usually 50 kΩ.
It works by injecting low level ac or dc on the line and detecting.
"Method for Remotely Managing an Enviromental Control and Monitoring Device" in Patent Application Approval Process
Jun 20, 2013; By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors Gordon, Michael...