Shock protection combines basic protection with independent fault protection, or uses an enhanced provision covering both (extra-low voltage, reinforced insulation); since Amendment 2, live parts must not be reachable without a tool or key under normal or single-fault conditions. Basic protection is by insulation removable only by destruction, barriers or enclosures of at least IPXXB or IP2X (IP4X on readily accessible top surfaces) chosen for the environment and mounting position the maker specifies and removable only with a key or tool or behind an interlock or intermediate barrier, obstacles, or placing out of reach (the last two only where access is limited to competent persons); an RCD is never the sole basic protection.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.