Actually, TT is one of the situations where equipotential bonding can work best. Where you have comparatively low earth fault currents you end up with a low voltage difference (e.g. between exposed- and extraneous-conductive-parts) - so a much reduced shock risk, even if ADS doesn't operate promptly (either by design - e.g. large or distribution circuits, or due to faulty protective device).
I'd qualify that, for an indoor TT installation - for one with lots of earthed metal outside - petrol stations, lampposts etc the situation is more like the outdoor EV charging case that gets so complicated - if there is a fault and the RCD fails to trip, the situation becomes un-avoidably dangerous. Even with the rebar grids earthed under concrete floors becoming live grids under concrete, while it may help reduce the risk of shock in a warehouse, does not really make it safer if this is outdoors. In such a case less bonding may be safer than more, in the very rare event of fault and an RCD failure.
Actually, TT is one of the situations where equipotential bonding can work best. Where you have comparatively low earth fault currents you end up with a low voltage difference (e.g. between exposed- and extraneous-conductive-parts) - so a much reduced shock risk, even if ADS doesn't operate promptly (either by design - e.g. large or distribution circuits, or due to faulty protective device).
I'd qualify that, for an indoor TT installation - for one with lots of earthed metal outside - petrol stations, lampposts etc the situation is more like the outdoor EV charging case that gets so complicated - if there is a fault and the RCD fails to trip, the situation becomes un-avoidably dangerous. Even with the rebar grids earthed under concrete floors becoming live grids under concrete, while it may help reduce the risk of shock in a warehouse, does not really make it safer if this is outdoors. In such a case less bonding may be safer than more, in the very rare event of fault and an RCD failure.
