In an N+1 UPS configuration with two 250 kW modules, what is the best upgrade option if the critical load increases from 200 kW to 300 kW?

In an N+1 UPS configuration, the "N" refers to the number of power modules needed to handle the load, while the "+1" provides redundancy to ensure the system can tolerate the failure of one module without compromising the power supply to the critical load. In this case, the current arrangement consists of two 250 kW modules, which totals a capacity of 500 kW, more than sufficient to cover the existing 200 kW load while also providing redundancy. However, a planned increase in the critical load to 300 kW necessitates a reassessment of the overall UPS capacity and redundancy.

Adding just one more 250 kW UPS module would make the total capacity 750 kW and keep the N+1 redundancy intact, as you would still have one UPS capable of handling the full load (300 kW) in the event that one module fails. However, this approach does not fully utilize the potential for enhanced redundancy and may not be the most efficient long-term solution as the load grows.

Replacing the current UPSs with larger models would also not guarantee the same level of redundancy when responding to future load increases. Upgrading to larger models means a significant investment and potential downtime for installation while also not providing an extra layer