yup thats the point of that extra 16Amp fuseare you 100% sure that if i use a 3amp kettle lead it will be absolutely fine? i'm just worried they will blow up or something.
If you really want to be sure change the fuse in the 3A kettle lead to a 1A fuse
basically the 16A fuse will blow way before a 3A or even a 1A on the main plug.
Likewise neither fuses should blow! they would only blow if there is a fault in the system and the blowing of the fuse is a safety thing to stop a fire from starting