With the increasing proliferation of electric vehicles, and the new “fast charging” technology, the need for a reliable and safe charging infrastructure is also increasing. Both the actual charging devices and the connected vehicles themselves need to be protected against overvoltages, as both have sensitive electronic components.

IEC 60364-7-722 [Requirements for special installations or locations – Supplies for electric vehicles]

The new standard IEC 60364-7-722, valid since June 2019, define that a connecting point accessible to the public shall be protected against overvoltages.

722.44 Protection against voltage disturbances and electromagnetic disturbances

722.443 Protection against transient overvoltages of atmospheric origin or due to switching

722.443.4 Overvoltage control

A connecting point accessible to the public is considered as part of a public service and

therefore shall be protected against transient overvoltages.

IEC 61851-23 [DC electric vehicle charging station]

Definitions and specifications for DC charging stations are treated in IEC 61851-23

A common mistake for the overvoltage protection for DC Chargers is the installation of a PV SPD.

E-mobility application has completely different technical demand and potential risks compared to solar PV application.

PV SPDs for solar application has been developed according to the withstand capability of inverters, which typically is >4kV

For the selection of a DC SPD for E-mobility, the IEC 61851-23 prescribe that the output voltage shall be limited at 2,5kV

12.7.101 Suppression of transient overvoltage at input (insulation coordination)

When applying the test setup of IEC 61851-21-2:2018, Annex E, with an impulse voltage according to IEC 60664-1:2007, Table F.1 at the input of the DC EV supply equipment, the DC EV supply equipment shall limit the output voltage to:

– 2500 V between DC+ and protective earthing conductor

– 2500 V between DC- and protective earthing conductor

It is important both to have the right equipment and to make the right choice depending upon the application.

If you take this into consideration, you will find a high-reliability business segment in electro mobility - and a suitable partner in Raycap.