Hello,

I need to buy a secondary PSU to deliver PoE to couple of devices in my home, just bought a CRS112-8P-4S-IN.
( devices including couples of pis powering their own SSD through USB if possible. + extra, AP ... )

in the manual :

With the included 28 V PSU the max power output of each Ethernet port in this mode is 1 A, the total maximum for all ports is 2.8 A. At 802.3af/at high
power mode the max power output is 450 mA per port, total max 1.4 A.

The MikroTik 48V 2A 96W part seems a bit pricey.

I condisder then buying this, but then I saw this : 48V 3A 120W , or even this : 48V 5A 240 W

My question is, is 48V 2A 96W the maximum for the secondary PSU ?

Will it handel 3A or even 5A ? How about 57V ? Any upsides ?

You can use power adapter with higher power output (more amperes), but it won't be useful ... grand total output current is (as stated) 1.4A, add switch's own consumption.
You can use adapter with higher voltage (e.g. 56V), wich will yield slightly higher power with same current.

Thank you