Internal Arc Classification of High voltage Metal Enclosed Switchgear

That is quite a tall order! Have you considered hiring a competent consultant?

http://www.acronymfinder.com/AFLR.html

Doesn't your protection scheme and site's fault current analysis dictate the fault rating sizing of the equipment on site?

An answer from a similar question

First of all, the IEC is not a mandatory document, and even more, the IAC classification according to IEC62271-200 remains an optionnal performance. It is your user's choice to specify it on not, and it should be based on some risk analysis.

Clearly, specifying internal arc withstand has an impact on the cost of the switchgear. Several parameters should be reviewed on the installation:

- the protection scheme, and the time settings of the protection upstream of the considered location; perhaps some kind of acceleration could be implemented also to shorten the required withstand duration;

- the short-circuit level, and when such fault level is actually present; if the maximum fault level only occurs under special coupling conditions, for instance, perhaps presence of personnel can be prevented during these conditions;

- the operating procedures and the surrounding of the switchgear; organising the switchroom wisely could allow saving on the switchgear...

The IEC standard gives some guidance on the relevant criteria to consider, in subclause 8.104, but it can't be made available for free. A Cired conference paper has been presented some years ago dealing with the global topic of safety facing internal arcs, and this paper can be downloaded from the Cired website at: http://www.cired.net/CIRED07/pdfs/CIRED2007_0133_paper.pdf