Certain installation instructions have to be observed when using BLITZDUCTOR XT Ex (i) surge protective devices in intrinsically safe circuits. In accordance with EN 60079-11;2007 a minimum distance (thread measure) of ≥ 50 mm must be maintained between intrinsically and non-intrinsically safe circuits (connecting parts, e.g. terminals)! When using the Ex i partition of type TW DRC MCM EX, this distance is also maintained if the surge protective devices are arranged directly next to one other. Ideally suited for use in conjunction with DRC MCM XT for condition monitoring of BXT modules.