Ev Charging/ Charging
Requirements
for EV Charger Installation
Each charger ‘should’ have its own socket outlet
and be on its own circuit.
As many consumer incoming mains are in the 35A to
50A range, even one added 16A charging socket-outlet can cause an overload. So,
when an EV charging point is added, the electrician should do a maximum demand
assessment. This can mean a consumer mains upgrade.
It may also
go further, requiring upgrading of the distributor lead-in from the street,
especially if there is more than one EV and they are on separate socket
outlets, as in AS/NZS 3000 Appendix P. Switchboard upgrading or replacement may
result, and additional AS/NZS 3000 requirements may apply.
For residential installations with PV there may be
some benefit when charging an EV. However, as most cars used for travel to work
or used at work will be away during the day, this may not be a solution unless
a battery system is installed.
These issues may be exacerbated for those living
beyond a city or large town, where the poles and wires may be able to carry
only small loads. In such cases, other solutions – including batteries – may
have to be considered.
Some retailers may off er tariff reductions, but
this can require an extra meter, changing to a smart meter, extra switching or
extra meter panel space.
Again it could mean a total switchboard
replacement, and other AS/NZS 3000 requirements – such as more residual current
devices (RCDs) – may apply.
Also, it is important to note that every point in
the charging, discharging and inverter system circuits will involve losses of
around 10% at each step and where this involves metered power, these losses
will automatically be included in the home occupier’s electricity bill.
All of this offers great opportunities for
electrical contractors keen to get involved and become known as EV specialists
including;
§ installation of socket-outlets and/ or chargers for every
residentially-homed EV
§ possible upgrading of consumer mains and power supply in-feeds
from the street; and,
§ possible upgrading or replacement of switchboards, meter panels
and RCDs.