Is my TT system correct for two EV charging points?

Question:

Any thoughts on earthing arrangements for two charging points on separate circuits from a building general lighting and power distribution board into a external car park. The charging points will be about 3m away from each other, the charging points are about 40m from the distribution board if we’re effectively making them into a “TT” system.
Do we use one rod and combine or two separate (distance between charging electrodes could be a problem due to limited space)?

Answer:

Hi there.

It is tricky for me to picture the scenario here, despite the explanation.  A couple of things come to mind.  If you have a TT system, you only  need  one electrode, but you can always have more.  

Also, whatever option you pick ensure that you don't have access to 2 different potential earthing systems at the same time.  This is a common issue with EVs.  

Also, check Amd 1 of BS 7671, this has additional information in following the update this year, as well as the excellent IET best practice guide to EVs.

Cheers

Gary Parker - ECA

Gary holds a Bachelor of Engineering Degree in Electrical & Electronic Engineering along with numerous years of experience across many aspects of the electrical industry.