Electrical protective device for electro-medical appts. - contains isolation transformer and resistive insulation monitor with safety switching

摘要

The device for protecting against contact currents consists of an isolation transformer (TR) and an insulation monitor (IU). The protected person (P) is connected via a resistor (R3) to the centre tapping of a potential divider (R1,R2) which is connected to the transformer secondary. A current change in the three resistors caused by a single or double insulation failure triggers a warning signal and/or the switching off of the device and/or the activation of a redundant protection device. ADVANTAGE - Ensures safe operation of one or more electrical devices irrespective of local safety measures and ambient conditions.