EV Supply Equipment EVSE – Key Updates in AS/NZS 4777.1:2024

EV Supply Equipment (EVSE) is essential for electric vehicles (EVs), influencing how they connect with the grid or other loads. It comes in two main types: DC EVSE and AC EVSE. Each type serves different needs and offers unique functionalities:
DC EVSE
This type delivers DC power directly to the vehicle. It is often used for fast charging and supports reverse power flow, which is useful for bidirectional energy transfer.
AC EVSE
This type provides AC power, which the vehicle then converts to DC. AC EVSE is typically used for standard charging and can be wall-mounted or portable.

Alternative Supply Arrangements

EVs that do not connect in parallel with the grid are not subject to AS/NZS 4777.2. This standard regulates inverters and generators connected to the grid. If an EV system isolates itself from the grid and uses power solely from the vehicle, it does not need to meet AS/NZS 4777.2 requirements.

Charging Modes

Modes 1 & 2
These modes are for plug-in charging and do not support reverse power flow. They are not covered by AS/NZS 4777.1. For details, see Appendix B of AS/NZS 3000, which outlines rules for electrical installations.
Modes 3 & 4
These modes support reverse power flow. Mode 3 uses a fixed AC EVSE unit, while Mode 4 involves a DC connection from the vehicle. Both modes enable bidirectional power transfer, which is important for technologies like vehicle-to-grid (V2G).

Installation Requirements

For reverse power transfer, the equipment must be permanently installed. Plug-in devices for Modes 3 and 4 are unsuitable for these applications. A permanent installation is required, although the plug at the vehicle end must fit the vehicle’s charging port.

Adoption of Charging Modes

Mode 3 (AC EVSE) is less likely to be adopted by vehicle manufacturers for bidirectional use. This is because it requires the vehicle to comply with AS/NZS 4777.2, which can be complex. Instead, Mode 4, which supports DC charging and is more suitable for bidirectional applications, is expected to be more widely used.
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