Fault Levels for CL Fusing of Transformers

[DCinAC]

We would be interested in knowing what most utilities use as the fault current level at which they install current limiting fuses on 3-phase pad-mounted transformers (to minimize explosion). We realize that: (1) bayonet expulsion fuses have a 3500 amp limit (so we may use fuses in air or a VFI); (2) most CL fuses are not large enough for very large transformers, (3) CL fuses my need to be paralleled for large transformers, (4); and smaller transformer may be more susceptible to exploding; but (5) fault currents might be higher where larger transformers are used because they require a stiffer system. (Base response on. 7.2/12.5 kV grd Y systems). Thank you.