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Balanced 3 Phase Supply for EVC

Mark Fleming

Hi,

Please could someone advise on the following regarding EV chargers on a balanced 3 phase supply. 

We are proposing to install 3 x 75kw DC rapid chargers from a new DNO connection solely for the EV chargers. The chargers themselves only require 3 phase & earth and the only 230v supply from the new connection is a small anti-condensation heater within the feeder pillar (20w). 

Can I therefor still use the rule of thumb from CoP J4 as Regulation 722.411.4.1 (i) has now been removed from amendment 2? 

When I calculate using Regulation 722.411.4.1 (ii) I end up with a minus number so I assume this shows an earth electrode & PME supply is not suitable?

Thank you in advance.

Mark

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  • 0

    I noticed that, but if it isn't part of the charger, does it matter?

    In the case of an open PEN event, the heater will pull the severed N/PE/installation metalwork up to the voltage of whichever line it's connected to. If there's no EV on charge at that moment (or the charger is only connected L-L-L), there's no (balanced) load that would create an artificial star point and  keep the N (& installation's PE) nearer zero.

       - Andy.

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  • 0

    I noticed that, but if it isn't part of the charger, does it matter?

    In the case of an open PEN event, the heater will pull the severed N/PE/installation metalwork up to the voltage of whichever line it's connected to. If there's no EV on charge at that moment (or the charger is only connected L-L-L), there's no (balanced) load that would create an artificial star point and  keep the N (& installation's PE) nearer zero.

       - Andy.

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  • 0 in reply to AJJewsbury
    AJJewsbury said:
    In the case of an open PEN event, the heater will pull the severed N/PE/installation metalwork up to the voltage of whichever line it's connected to.

    Only in the absence of extraneous-conductive-parts, or a consumer's earth electrode.

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