Craftsmen are often faced with the problem, you need to connect your power tools on sockets, whose functional safety do not check. Faulty electrical installations (e.g. lack of protective conductors, or interchanging of the protective earth conductor and outer conductor) are normally not visible without a more detailed investigation and thus particularly dangerous. This can result in serious accidents. The PRCD-S + the PCE protects the user against faulty electrical installations.When plugging in the PRCD-S + into a socket with unknown protective measure, there is an automatic routine testing. Only if the socket in a faultless us safe condition (signal unit flashes green), the PRCD-S + switch on. The signal unit is permanently illuminated in the color green. Only now can the electric load is switched on.After commissioning of the electrical load that is used for the PRCD-S+ as residual current operated circuit breakers and protects the user against dangerous currents, which can be caus