Bender_Monitor_2021_75_EN

52 As the value of subsidies for developing such a charging infrastructure increases, more and more players and products enter the market, making it harder for users to understand the situation clearly and compounding their uncertainty. But amid the confusion of the race to set this undertaking on its feet and in the face of ever more complex requirements combined with shorter time- to-market, it is imperative not to neglect the question of “electrical safety”. In essence, the following applies: Particularly in the realm of cable-based AC charging, the requirements governing a safe yet interoperable charging infrastructure are already thoroughly described in the national, European and international standards and have proven themselves in practice. But at the same time, misunderstandings arise repeatedly regarding certain formulations and requirements of the standards. One misunderstanding that occurs very often on the subject of cable-bound AC charging modelled on charging mode 3 – referred to in the following as mode 3 charging for short – is that a type B residual current device (RCD) must be installed for each charging point. Meanwhile, the solution described as Standardisation Bender Group _ Smart protection concept for AC charging infrastructure modelled on charging mode 3 Following the Federal Government’s undertaking to reduce greenhouse gas emissions in Germany by a total of 55 % compared with 1990 by 2030, not a day goes by without discussing the electrif‌ication of road traff‌ic and the comprehensive, reliable charging infrastructure which is essential for it. equivalent in the pertinent standards, a type A RCD combined with 6 mA DC fault current monitoring and a disconnecting device (RDC-MD for short according to IEC 62955:2018), is overlooked without reason in many cases, and is even characterised as unsafe. The purpose of this article is to address this view, which is unsupported by facts. In so doing, this article will also explain the combination of a type A RCD and RDC-MD, which is superior in many ways, as part of the total safety concept of a standard-compliant mode 3 charging device. Smart protection concept for mode 3 charging infrastructure At bottom, the argument regarding electrical safety is based on the mistaken belief that when a DC fault current > 6 mA occurs, it is imperative to separate safely from the power source. This, in turn, begs the conclusion that the requirement can only be satisf‌ied with a type B RCD. In response to this, the existing standard situation must f‌irst be explained. The standards considered most signif‌icant for the electrical safety of a mode 3 charging infrastructure are the installation standard