did someone say generator
Only dirty people wash
Hi barge so you know the risks with boats then, are you aware the regulations for boats is basically the same as for caravans. No read the link you may find the joined up explanation satisfies you
Last edited by Alf; 12-10-2017 at 20:09.
The electricity company also supply a separate earth voltage connection. That is the wire that all the earth pins on electrical plugs are connected to, so all the metal cases of appliances are connected to it. So whatever derangements happen inside the appliance, you can't touch a live part: just the earth voltage.
However, that earth voltage might be the earth at the substation, but it may not be earth voltage in your house. To make sure that your house's idea of earth is the same as the earth wire's, the house is connected to it as well. This is called Protective Multiple Earthing (or PME for jargon). All the pipes and wires are joined to the earth cable using fat wires. This ensures that you are protected by a "mesh" at the same voltage as the earth cable.
This is fine as long as you are indoors. But take a cable out to your motorhome and you have left the house. Yes, you could easily connect the bodywork and anything else inside the motorhome to the earth voltage, but the tyres are rubber. The motorhome has no electrical connection to the outside soil. What happens if you step outside onto damp soil at a different 'earth' voltage? I'll tell you what: you could possibly get a shock. Not likely, but possible.
Much the same is true of taking an electric mower or hedge trimmer outside, but generally these have no earth at all. They are "double insulated" and in addition, any socket used for cables going outside has to have a low current RCD - which is a device that compares the current going out on the live with the current coming back on the neutral. On the "I counted them out and I counted them back in again" system, if it detects that if any of our electrons are missing in action, it cuts the current off very fast indeed.
So when you use a simple 13A to hookup adapter, you have at least* one RCD protecting you. Any mains current flowing to earth will cut the power. Good enough for occasional use. But it would still be better if the motorhome's earth supply was at the same voltage as the local earth. And it is easy to do if you are wiring a dedicated hookup socket: just hammer a metal spike into the ground and connect the socket's earth wire to that instead.
Personally, I grew up in a world where cars didn't have seat belts. I rode a motorbike for years before helmets were compulsory (when I rode them on the road, I generally wore one, though). Our house wiring had 15A and 5A sockets and wire fuses. And I survived. But nowadays these are unnecessary risks.
*The house will have an RCD in the fusebox. The outdoor socket will probably have a more sensitive one of its own. And the motorhome will have one in its mains wiring.
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