Hi,
please answer my quotation. How switching between PSUs on my mikrotik 1009-7g-1c-1s+ if voltage is equal on both PSUs ?
What delta in voltage is define main PSU ?

Regards.

The 2 PSUs (and the PoE input) are just wired together using a couple of diodes.
There is no switching.
There is an indication if the PSU is outputting voltage in System->Health.
This status is also available via SNMP.