With PEN fault protection generally being provided within the Charge device itself (ie not at the origin of the circuit) would you advise bonding the mounting post if it has exposed (extraneous) metal parts? Assuming a TNCS supply.
My feeling is that we are damned if we do and damned if we don't. Elcb Switch
If bonded; In the case of an earth fault in the car and MCB only at origin, we do at least have equipotential hand to hand, even if not hand to foot. However, the MCB is unlikely to trip, so we rely on the RCD within the charge point, if there is one.
And of course with an RCD at the origin, earth leakage through the post will trip the RCD.
However; in the case of a PEN fault, there will be no tripping and our bonding will have introduced a lethal voltage on the metallic post even when the car is not present.
I would advocate it being a requirement that all charge points, which incorporate PEN fault detection; MUST have an additional, accessible earth terminal which originates downstream of the PEN fault relay, if they are to be used in areas close to extraneous parts and therefore requiring bonding. Thereby bonding is removed in the case of a PEN fault being detected.
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