Caution: For all work a power supply disconnection is necessary!
\nThe earthing connection must be performed by a qualified electrician or under his supervision. The circuit may only be operated with residual current circuit breakers (FI or RCD).
\nGrounding is only possible with a TN-C-S or TN-S system. It must not be grounded with TN-C systems. This is absolutely required to be checked in advance.