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Electrical Vehicle Chargers - No Diversity?

Good afternoon

I have a question to address to more experienced engineers in here about the load calculations around EVCs

Its clearly stated in BS7671 that no diversity should be applied to an EVC

This is a bit weird to me as to the ramifications it has

So, assuming we have a TPN 32A EVC, this means you cant apply diversity and feed it with a 20A MCB. It should always be a 32A MCB

All good

What happens in case you have a DB feeding 5 off these chargers?

Assuming you do not have a load management facility between the 5 chargers, does the 'no diversity' mean I have to assume a DB charged with 5 x 32 = 160A load????

And protect it with 160A, and install a cable for 160A etc etc etc?

Is this what no diversity means for the EVCs?

Always assuming you do not have a load management system installed in the EVCs

Thanks

Parents
  • As we start to consume more electricity I can't see how a EV charging point supplied from a existing building supply can be installed without load management  - i think it will become a  minimum standard. Some charging points have internal dip switches that allow you set the max current -a crude way of reducing the max demand - and extending charge times.

Reply
  • As we start to consume more electricity I can't see how a EV charging point supplied from a existing building supply can be installed without load management  - i think it will become a  minimum standard. Some charging points have internal dip switches that allow you set the max current -a crude way of reducing the max demand - and extending charge times.

Children
  • I would definitely agree with your comment. But this is a different discussion. My experience from small scale buildings like hotels says that the clients do not want to pay extra for an overall load management system. So this cames back to me as a designer to make sure that the boards are big enough to feed the number of EVC chargers without any diversity as per BS7671

  • A bigger board is not going to help you.

    You need a bigger supply or a smaller load (or load management).