Electrical supply
Single phase vs three phase power for EV charging
Your supply type decides which chargers are practical at your property. Here's what each means, how to identify yours, and when an upgrade is worth considering.
Most Melbourne homes
Single phase
One active supply conductor feeding the house. It runs everything in a typical home, including a dedicated 7kW EV charger circuit, without difficulty.
- Supports chargers up to about 7kW
- Adds roughly 40km of range per hour
- Simplest and cheapest charger installation
- Load management may be used to protect the main supply
Less common in older homes
Three phase
Three active supply conductors, more common in newer builds, large homes and properties with ducted air conditioning, pools or workshops.
- Supports 11kW and 22kW chargers
- Faster charging where the vehicle allows it
- Heavier cable and more protective devices
- Higher installation cost than a single phase job
Identify yours
How to check your supply safely
Open the switchboard door — the hinged cover only — and look at the main switch. One main switch generally means single phase. Three main switches, often mechanically linked, generally mean three phase.
Never remove the switchboard panel, touch wiring, or open sealed sections. If you are unsure, photograph the board with the door open and let an electrician interpret it.
Your electricity bill and meter can also indicate supply type, but the switchboard is the clearest signal short of an electrician's inspection.
Is upgrading worth it?
Going from single to three phase means new supply cabling from the street, distributor approval and switchboard work. For EV charging alone, the extra speed rarely justifies the cost — a 7kW charger already replenishes far more range overnight than most people drive in a day.
It can make sense if you are already upgrading for other reasons: a renovation, a large air conditioning system, a workshop, or a household running two EVs with high daily kilometres.
Common questions
Supply type FAQ
How do I know if my home is single or three phase?
Look at the main switch in your switchboard. A single wide main switch usually indicates single phase; three linked main switches (or a wide three-pole switch) usually indicates three phase. A licensed electrician can confirm it definitively, and a clear switchboard photo is often enough for an early view.
Do I need three phase for an EV charger?
No. A 7kW single phase charger suits the majority of Melbourne homes and fully charges most EVs overnight. Three phase is only required for 11kW and 22kW chargers.
Can I upgrade from single phase to three phase?
Sometimes, but it is a substantial job involving your distributor, new supply cabling and switchboard work, and it is not always possible depending on the street supply. It is rarely worth doing purely for EV charging.
We are an information and quote request service — we do not carry out electrical work. All installations are performed by licensed electricians.
Keep reading
More Melbourne EV charging guides
Independent, jargon-free information to help you work out what your home actually needs.
How much does EV charger installation cost?
What actually drives the price of a home EV charger installation in Melbourne, and which parts of the job vary the most.
Read guide7kW vs 11kW vs 22kW
Charging speeds compared in plain language, including why your car's onboard charger often sets the real limit.
Read guideCan I charge from solar?
Solar diversion, battery integration and what to look for in a charger if you already have panels on the roof.
Read guideDo I need a switchboard upgrade?
Why some homes need switchboard work before a charger can be installed, and how to spot the warning signs.
Read guideWhich EV charger is right for my car?
The main categories of home charger sold in Australia and the features worth comparing before you buy.
Read guideReady to get EV charger quotes?
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