722.411.4.1 (iii) requires a device to provide isolation of all live conductors

Not just live conductors, but the PE too!

An equivalent means of functionallity can be included within the charging equipment. This is usually a contactor. Does this contactor need to compy with Table 537.4, or is it sufficient to select a contactor that: meets the overvoltage category; has at least 3mm of contact separation and has been tested to BS EN 60947-4-1?

Tricky. In normal circumstances it would be a simple case of the equipment standard overriding BS 7671 and often equipment standards take slightly different approaches, which could allow that sort of thing. At the moment there is no standard for open-PEN devices (although there is one for EVSE in general), so it's a bit up in the air. Current advise seems to be to adhere to general safety legislation plus some 'declaration of conformity' from a suitable 3rd party - so it's all a bit slopey shoulders onto a testing house.  I guess the general principle is that if you want to do something differently from what BS 7671 suggests, you need to be able to show that it's no less safe in all reasonable circumstances.

marked with the isolation symbol  (I have been unable to find a contactor with this marking, so far).

Just thinking aloud (i.e. I've not thought this through properly yet) - does it have to be a contactor? Could you use something else like an 3P MCB (which typically are rated for isolation) and a shunt trip? Obviously you'd want it to fail safe (i.e. be open under an open PEN event even if the L-N voltage was too low to drive the electronics) so maybe you'd want more of a 'shunt close' rather than shunt trip, if such a thing exists. Just wondering...

   - Andy.

Thanks for the response Andy.

I am looking at existing installations and most manufacturers have opted for a contactor in the EV charger to provide isolation for all live conductors and the PE. Only matt:E have gone though the process with IMO to get their contactor certified (but it is not for general sale).

Thanks for the response Andy.

I am looking at existing installations and most manufacturers have opted for a contactor in the EV charger to provide isolation for all live conductors and the PE. Only matt:E have gone though the process with IMO to get their contactor certified (but it is not for general sale).