rcd question

Can anyone tell me if there is a specific requirement for a mobile snack bar to have rcd protection on the sockets? The sockets are not used for anything outside the vehicle and the vehicle is eebads protected; it is the type that is stationary most of the day running off a small generator and is driven (or towed) home at night.

are you sure its eebads? Small mobile generators normally provide protection by electrical separation.

you've got me there, I know nothing about these generators, I mistakenly assumed as it is wired with a domestic consumer unit with normal earthing it would be eebads, but as there is no earth to the supply it can't be that. Can you tell me how this protection works in practice?

Electrical separation works by there being no connection of the supply to earth. Under single fault condition no current can flow through a person to earth as there is no path for it to return through earth to the supply. Under the single fault condition the supply can use the fault path as a reference point and the supply oscillate around it. If this fault is not picked up and rectified and a second fault occurs, exposed conductive parts can become live at the opposite polarity, hence this is why exposed conductive parts should be equipotentially bonded together (but not to earth). As this fault is in effect a short circuit through the equipotential bonding, double pole protective devices should be used.
RCDs are of little use as they work on the current balancing method, if both faults are after the RCD it will not operate.

I assume all the earthing must be in place in case the van is connected up to an earthed electrical system with an extension lead, and for a generator for protection we are looking at seperation and bonding......food for thought, thanks.