IMO only consider the primary side of the transformer as this is really the only fuse which amy be affected.
This is due to the transformer stepping down to the required voltage and then all fuse values and voltages there after are as per diagram/schematic.
If I am correct in the US which uses 110v single phase mains voltage they prefer 8A fuses on primary.
In Aus we have 230v single phase mains voltage and we recommend 5A fuses on primary.
Does that help Dude.
