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Electrical Vehicle Chargers - No Diversity?

Apostolos

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

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    Well if the alternative is paying the DNO to lay in a larger supply ,and perhaps a new substation,  or arranging coordinated load management, I suspect that the latter will be back on the table again, certainly when you get above two chargers, and in many cases even for one large one. Charger manufacturers have by and large already woken up to this and can advise how to do it.

    In effect the only time any car gets charged at full rate is when no-one else is plugged in. If you do not do  it like this, then there is a very credible risk that 5 cars will one day all be plugged in and all drawing the full current for a few hours together. It is not like electric showers where the use time is short compared to the heating of the cables and the substation transformer.

    Mike.

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  • 0

    Well if the alternative is paying the DNO to lay in a larger supply ,and perhaps a new substation,  or arranging coordinated load management, I suspect that the latter will be back on the table again, certainly when you get above two chargers, and in many cases even for one large one. Charger manufacturers have by and large already woken up to this and can advise how to do it.

    In effect the only time any car gets charged at full rate is when no-one else is plugged in. If you do not do  it like this, then there is a very credible risk that 5 cars will one day all be plugged in and all drawing the full current for a few hours together. It is not like electric showers where the use time is short compared to the heating of the cables and the substation transformer.

    Mike.

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