Yes

You may prefer the English/French language version of that graph on page 37 of https://sigmaelektrik.com/wp-content/uploads/2018/04/1-LV-Moulded-Case-Circuit-Breakers.pdf

which  has the captions in a more recognisable format Think of "ust"  as upper switching threshold if calling it "Limite Superior" is not to your liking.

You may also wonder about the 4 lines instead of 2 and it had me looking until you realise that this is a graph for two breakers, the S250, and the K 250 overlaid. Doh!

Which do you have?

Mike.

Yes

You may prefer the English/French language version of that graph on page 37 of https://sigmaelektrik.com/wp-content/uploads/2018/04/1-LV-Moulded-Case-Circuit-Breakers.pdf

which  has the captions in a more recognisable format Think of "ust"  as upper switching threshold if calling it "Limite Superior" is not to your liking.

You may also wonder about the 4 lines instead of 2 and it had me looking until you realise that this is a graph for two breakers, the S250, and the K 250 overlaid. Doh!

Which do you have?

Mike.

Cheers Mike!

Not sure which model is in place. Was not on this particular install which is supplying a cubicle for several EV charge points. The 200A MCCB provides an underground supply to the cubicle via a swa which is earthed at the supply end only. TNCS earthing arrangement..  From the cubicle out to the EVSEs all is TT. 

Apparently the Zs at the disconnected swa and inner earth core sum to a measured Zs of 0.22ohms. I think we did have a discussion about the do's and dont's of not earthing the swa and it was thought imprudent to rely on it for mechanical protection only???