53 DIN VDE 0100-722 (VDE 0100-722) which deals with connection to the low-voltage installation, and the product standard DIN EN IEC 61851-1 (VDE 0122-1) which concerns the AC charging infrastructure, both of which were formulated by the German Commission for Electrical, Electronic & Information Technologies of DIN and VDE (DKE). For the point at issue, the relevant committees are DKE/K221 “Electrical installations and protection against electric shock” and DKE/K353 “Electric vehicles”. Both of these bodies are in agreement regarding the safety of using the constellation of type A RCD and RDC-MD, as is evidenced in VDE 0100-722:2019- 06 section 722.531.3.101 and DIN EN IEC 61851- 1:2019-12 section 8.5. In both documents, it is stated unequivocally that 1. the use of a type A RCD in combination with a RDC-MD is unreservedly equivalent to the use of a type B RCD and 2. disconnection following the occurrence and de- tection of a DC fault current > 6 mA is suff‌icient, and is not to be confused with safe separation of the power source. It is most important to draw a clear distinction between the protection function for personal protection and raising the level of protection in order to guarantee performance of the protection function. The def‌ining issue is: › The protection function against electric shock is assured at all times by the protective device (type A RCD) which is required in the installation for each charging point and is used explicitly for the safe separation of the AC circuit when a residual current > 30 mA occurs. › The function of the RDC-MD described in the standardisation community as raising the pro- tection level ensures that the protective function of the type A RCD is maintained in case of a DC fault current > 6 mA, which must be complied with in the f‌ield of e-mobility. EXPERT KNOWLEDGE Continued on the following pages