Our daughter and her family, including 2 small children will join us on holiday in a couple of weeks. They will stay in their tent next to our van and to give them maximum independence they want their own hook up. I have seen hook up cables for tents on ebay for about £15 but they are simply a length of hook up cable with the blue plug on one end and a strip of sockets on the other but no RCD so are they safe. Is an RCD needed or do the site electrics provide adequate protection? Thanks, Jim.