As the lamp post are going to be located next to the parking bays, adopting a TT earthing system for the chargers is not really an option.

Probably worth talking to the particular DNO in question - it's been reported that some aren't entirely convinced by open-PEN devices and will often refuse to supply a PME earthing terminal for on-street type charging installations. Their preferred solution would then to TT the charge points - together with anything else that's within reach (e.g. lamp posts). (I guess you could have a common TT earthing system even if the metering was split).

   - Andy.

Hi Andy,

Sorry back to this one,

So where we might have an on street installation and the DNO have confirmed we could have a PME supply to the feeder pillar, along side an O-Pen device complying with 722.411.4.1 (iv) and the supply is from the same DNO cable in the street as the lamp post, do we still need to treat them as a sperate earthing systems and keep them apart as with a TT and PME?

Mark Fleming said:

So where we might have an on street installation and the DNO have confirmed we could have a PME supply to the feeder pillar, along side an O-Pen device complying with 722.411.4.1 (iv) and the supply is from the same DNO cable in the street as the lamp post, do we still need to treat them as a sperate earthing systems and keep them apart as with a TT and PME?

No that example is NOT a separate earthing system.

Mark Fleming said:

and keep them apart as with a TT and PME

The requirements of Regulation 411.3.1.1 regards simultaneously-accessible exposed-conductive-parts applies whatever the earthing arrangements wherever ADS is used. Therefore, would also apply if you had an existing building supply, powering lights in the car park, and you bring in a new supply for the EV charging points - the charging points and lights would have to be on the same earthing system.

How you might achieve that depends on a lot of different factors.

Mark Fleming said:

So where we might have an on street installation and the DNO have confirmed we could have a PME supply to the feeder pillar, along side an O-Pen device complying with 722.411.4.1 (iv) and the supply is from the same DNO cable in the street as the lamp post, do we still need to treat them as a sperate earthing systems and keep them apart as with a TT and PME?

No that example is NOT a separate earthing system.

Mark Fleming said:

and keep them apart as with a TT and PME

The requirements of Regulation 411.3.1.1 regards simultaneously-accessible exposed-conductive-parts applies whatever the earthing arrangements wherever ADS is used. Therefore, would also apply if you had an existing building supply, powering lights in the car park, and you bring in a new supply for the EV charging points - the charging points and lights would have to be on the same earthing system.

How you might achieve that depends on a lot of different factors.