Some touring caravans, both motorised types and trailers have a UPS of several KW capacity. this supplies the same sockets with either mains power from a shore supply, or with an inverted supply from a battery bank. Charging of the battery is automatic from the shore supply, and sometimes also from the vehicle engine. Such systems are safe and can not produce a dangerous voltage on the exposed pins of  the plug.

but if they don't export, then there is no need for a bidirectional breaker.
Mike.

but if they don't export, then there is no need for a bidirectional breaker.
Mike.

Agree.

What about burnt out neutrals,  could Bi directional and Dual Pole help in that situation?

RCDs for caravan sockets should be double pole anyway (as with any isolation device on TT systems). Residual devices of any kind generally won't detect neutral problems, as there's no corresponding residual (or leakage or earth fault) current to detect. Bi-directional ones aren't any different from unidirectional ones in that respect.

   - Andy.