Insulators for a Bus Duct?

For the support 1000VDC, 12500A Bus duct to the Structure (ceiling or walls) we need to provide the non-tracking insulators to withstand short circuit stresses at least 200 KA (Sym) and 325 KA (Asym) short current.

In additional, the insulators should be capable to hold weight at least 400Lbs.

Please direct us which insulator we can use.