I have been running some design calcs with Trimble ProDesign, selecting a 63A Type C iC60H Schneider MCB as the protective device.
The circuit has a Zs of 0.51, a disconnection time of 3.2s and fault current of 0.43kA, according to trimble, and trimble has passed this as acceptable.
By chance i was looking at table 41.3 and noticed the max Zs it states is 0.35, see screenshot
Now i am sat here thinking that doesn't make sense but i doubt neither Trimble or BS7671 is incorrect, so can someone educate me please.
Thank you in advance.