When grid power goes out, all servers in a rack lose power immediately. The server administrator confirms the servers have dual power supplies, which are connected to separate PDUs. Each of the PDUs i

If both UPS devices were set for the wrong voltage, it's more likely they would have caused issues before the grid power outage or failed to operate correctly from the start, rather than failing only during an outage.

For both PDUs' power circuits to trip simultaneously at the exact moment of a grid power failure is highly unlikely unless there was a massive surge, and even then, the UPS units should have protected against it if functioning correctly.

It is extremely improbable for all server power supplies in an entire rack to fail simultaneously at the precise moment of a grid power outage, especially when equipped with redundant power supplies.

If the UPS batteries are discharged or have failed, they cannot provide backup power when the grid goes out, leading to immediate power loss for connected equipment. Given that all servers in a rack lost power immediately and the setup includes two separate UPS units, it suggests a widespread failure of the battery backup capability for both units.