I’ve been searching this morning for a Swiss extension cord that is thinner than normal. It temporarily needs to go under a door, which needs to be closed.
Migros, Coop, Jumbo, Hornblach have extensive collections but none seem to offer anything slim. Width isn’t important!
Keep in mind that a thinner cable might mean more resistance in the line, leading to blowing a fuse. It all depends on what you want to use it for. A washing machine would probably be out of the question.
It's not the voltage that's going to be the main problem, that's just a question of the insulation, but the thickness of the copper. Standard Swiss socket outlets are rated at 10A and on an extension cord you therefore need cable that is rated at 10A. If you put together your own extension cord with your own cable, plug and socket, you really need to make sure you never plug a washing machine into it. Also running an unprotected cable under a door isn't terribly kosher either. With time the door is going to work off the insulation.
As an alternative, what about drilling a hole in the door frame?
I don't want to be difficult, but I've seen and read too many cases of poor electrical installations causing fires and electric shock (the Grenfell Tower disaster for one).
If you do a google search for it, it seems to be available on other sites where you can only buy one at a time. For example, I think this is the same one:
Thx Pancakes, but that doesn’t actually look any thinner than a normal one. The first photo on Galaxus was misleading.
I’m actually tempted to take my Swiss Army Knife and cut off a couple of cm of insulation (without cutting the wires), flatten it, retape it and be done with it.
"Will power an 230v AC - 12v DC converter Max 25W."
Does the appliance you wish to use have an 2 pin or a 3 pin plug ? The extension cables with 2 pin plugs/sockets can be very thin because these are intended for low current appliance such as lights.
That may be less of a problem than, assuming door and frame fit well, the copper wire getting bent over the eges and forced even thinner at those points.
Building on this thought, could you, instead of extending the 230V supply, extend the 12V DC wiring? You are looking at just over 2A power ... so, you need wires that can handle give-or-take 3-4A to be safe. Depending on the distance etc, you can make do with fairly thin cabling