I have two 10kva UPS available pulled from production and ready for new homes.
https://www.apc.com/id/en/product/SURT10000XLI/smartups-rt-10000va-230v/
This accespts either 230V or 400V 3 phases input (hard wired)
No warranty left but have been no problem for a long time. I am not sure I have the cover for the batteries.
RRP was well over $10k .. Looking for $800 each.
Pick up only from our office in Albany due to size and weight.