This seems to be a recurring issue around here.

I just installed two modules into my G6 frame to completely fill it
and the fuse blew on power up. I double checked all of the module
connections and there were no errors there and the total current
required by the installed modules is under 600mA so I think it is just
one of those transient power on spikes that seems to happen.

I'm running the 240V PSU2 which specifies a 250mA slow blow fuse and I
know Dieter has mentioned that 300mA or maybe even 400mA would be OK
to use however I'm having trouble locating slow blow fuses in such low
current ratings, the lowest I can find here is 500mA. I know that this
is twice the specified current rating but would these be considered OK
to use given that in the case of a short to ground they will still blow

Cheers,
Adam-V.