It's easy enough to make up a hook-up lead yourself. All you need is a 240V,
16A plug (blue, round 3 pin), a length of arctic cable and a socket(s) for
the tent end. You could put an RCD-protected socket on but they are very
expensive and most (all?) site supplies are protected anyway.
The whole lot will only cost about £12 ~ £15 to make (unless you get the
sparkies in work to make one up, then it's free!)
I think you'll find that some site owners (eg C&C club) demand an ELCB
and overload protection in the unit.
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