Paul,
That's a rather valid and interesting point you bring up.
Over here, caravans and motor-homes are classed as "Connectable Installations".
Bear in mind that some caravans have switch-boards in them and others don't.
Before a caravan can be connected to a power supply here, it must have a current Electrical Warrant of Fitness, issued by an Electrical Inspector.
Also, bearing in mind that some motor-homes also use a Dual-Voltage system, a muck-up in the wiring system could be catastrophic!.
To be honest, I've never wired a caravan or motor-home, but I have tested and repaired a lot of them in the past.
To my way of thinking (however rather simplistically though), shouldn't a caravan really be regarded as an oversized appliance, like a big toaster, after all you still plug it in before you use it, don't you?. [Linked Image]