How to earth SWA to external EV charge point

[peterinreading]

I am looking at section 722 of 18th edition for EV charge points. Section 722.411.4 imposes restrictions on the earthing arrangements for TN systems. For an external chargepoint connected to a domestic PME supply the accepted solution to avoiding the restrictions of 722.411.4.1 seems to be to provide a separate earth rod for the charge point and separate this from the PME earth i.e. an independent TT arrangement. My question is as follows: if SWA is used to feed the external chargepoint, how should the armour be earthed to avoid interconnecting the PME and the charge point's earth rod? This must be quite a common scenario for an external chargepoint fixed to a pole in a driveway.

 

[Octopus]

At the supply end only

 

[SparkyChick]

@Murdoch beat me to it

 

[Nigel]

Earth at the supply end and terminate at the load end into a plastic adaptable box.

 

[Simonslimline]

 

[peterinreading]

Thanks Essex - I see now that corresponds to 542.1.3.3.

Where does the plastic box go? Buried under the pole and filled with gel? There isn't space in the charge point and it will look really crap to add some other box to the post. I am looking to use 4mm2 two core SWA. What cable should I use from the plastic box to the charge point?

 

[peterinreading]

Simonslimline: That might work but in my context you also have to make sure the outside of the gland is insulated from the post.

 

[Octopus]

Thanks Essex - I see now that corresponds to 542.1.3.3.

Where does the plastic box go? Buried under the pole and filled with gel? There isn't space in the charge point and it will look really crap to add some other box to the post. I am looking to use 4mm2 two core SWA. What cable should I use from the plastic box to the charge point?

If the charger enclosure is insulated, then gland the swa directly too it.

 

[Deleted member 26818]

Another option is to install a charge point that doesn’t require an Earth electrode.

 

[suffolkspark]

If the charger enclosure is insulated, then gland the swa directly too it.

but then you'll have 2 earthing systems within inches from each other inside the unit? might be ok as its inside the box but I dunno if I like it.....

those linked glands look good didn't know they existed
does anybody remember the "bite" glands that were like a conventional swa gland but plastic? don't think they exist anymore

could always just sleeve the armouring and fit a compression gland. obviously make off into proper gland at source end

 

[Octopus]

but then you'll have 2 earthing systems within inches from each other inside the unit? might be ok as its inside the box but I dunno if I like it.....
could always just sleeve the armouring and fit a compression gland. obviously make off into proper gland at source end

In the meantime , this is what I, and I suspect many others would do ...

Come the 1st amendment of the 18th edition we may be adding rods to all PME sites ...............


As it stands "specialist" installers are already using PME earths from what I see ...............

 

[Dave OCD]

Well I have a 'normal' double external socket to fit later this week and one of its uses will be for a car charger with 13a plug connection. PME at this location and there won't be any rod going in.

 

[Deleted member 26818]

From the installation guide for the POD Point solo unit EV charger:

“The POD Point Solo features an on-board monitoring system to detect low voltage supplies and potential earth problems, If such a condition is encountered the charge cycle is ended and the vehicle becomes isolated from the incoming supply and effectively becomes double insulated.
These features emit the need for the installation of an earth electrode and the POD Point Solo unit can safely be connected directly to a TN-C-S (PME) earth system without any special arrangements. The POD Point Solo complies with regulation 544.14.1 of BS7671.“

 

[Miles Harling]

Interesting about the Podpoint solo and I wonder if other ‘specailist’ installs / equipment also meet the new regulations.