I wasn't sure whether to ask this here or on https://electronics.stackexchange.com/ but this seemed the more appropriate place, please migrate it if not.
I'm in the UK and I've got a wall mounted connection unit (see picture below) with a 5 amp fuse in that leads to a socket outside and a lamp post in the garden.
The outside socket is used for plugging in a catering van to charge the battery, but also to use the sockets inside and power the 12v lighting when it's parked on the drive.
Now the fuse blows sometimes if you plug two things into the sockets in the van, but today I found it had blown sometime between last night and this morning (it was fine last night). When I went to change the fuse it blew the new one straight away. I had to unplug the van and remove the bulb from the outside lamppost before I could put a fresh fuse in and not have it blow.
I can still charge the van (which is the main use for the socket outside) but it would be nice not to have to worry about it.
So my question is, can I put a 13 amp fuse in the unit instead of a 5 amp one? Will this cause any problems (like short circuiting the houses fuse box instead of merely blowing the fuse in the unit) or be dangerous?