LV cable sizing for short circuit condition (NEC)
I assue you are in the US. Perhaps not.
 I do not know the regulatory needs for NEC (National Electric Code) design, not having waded through the documentation below, but design sizing would not usually be associated with testing in any way.
 Design is usually a matter of using tables or calculators or performing calculations and applying relevant requlatory  codes. 

After installation you "will need to" [tm] test the installation, but that is another issue.



Liable to be very useful Complicated attempt to simplify confusing NEC requirements

Cable sizing table {NEC extract}

Here is a useful online NEC cable sizing calculator

Another NEC cable sizing calculator

Sizing tables here - solar emphasis.

Advice and sales pitch for their software here
 Why they, and others, think you may want expert assistance:





Basic NEC design rules here

Simplified guidelines for Joe average



Related:

Very nice Belden cable catalog

Cable fire ratings brief

Fire alarm cable specifics

Cable fire testing

Cable flame testing