Single phase vs three phase power: which does your Melbourne home have?

What is the difference between single and three phase power?

The difference between 3 phase and single phase power is the number of active wires bringing electricity to your home. A single phase connection has one active wire and one neutral, and every appliance runs from that one active. A three phase connection has three active wires, so the load can be spread across three, and each phase has its own capacity. The Victorian Government’s guide notes that most homes are connected with a single phase connection.

How to tell if you have three phase power

Here is how to tell if you have 3 phase power in about two minutes, at the meter box and switchboard. In 2006 the Victorian Government decided to fit smart meters to every home and small business (Australian Energy Regulator), so your meter is most likely a digital one with a screen. To make sense of the numbers on that screen, see how to read your smart meter.

Look, don’t touch: you only need to read labels. Never remove covers, seals or fuses in the meter box or switchboard; that is work for a licensed electrician.

1. Read the meter’s rating plate. A 3 phase meter looks much like a single phase one, so the printed label is the tell. Open the meter box door and read it (no need to touch anything). “1 phase”, “1P” or a single 230 V rating means single phase. “3 phase”, “3P” or 230/400 V (often written 3×230/400 V) means three phase. The highest voltage on the plate is the quickest tell: 230 V for single phase, 400 V for three phase.
2. Look at the main switch. In your switchboard, find the switch marked “Main switch”. A single switch means single phase. Three switches joined by a bar, or one wide switch covering three positions (a 3-pole main switch), mean three phase.
3. Count the service fuses. Many meter boxes have a sealed service fuse for each phase on the incoming supply: one for single phase, three for three phase. They’re sealed and live, so look only.
4. Still not sure? Ask your electricity distributor, or ask us to check at the free inspection. Your distributor depends on where you live in Melbourne or regional Victoria; the Victorian Government lists the five and their areas on its Find your energy distributor page.

What it means for solar

Your phase sets the size of the inverter your electricity network will connect, and the inverter is what the networks limit, not the panels. Every Victorian network (AusNet Services, CitiPower, Jemena, Powercor and United Energy) pre-approves up to 10 kW of inverter on a single phase home and 30 kW on a three phase home, counting solar and battery inverters together (connection policies checked October 2026); larger systems can apply through a paid or negotiated assessment. A 3 phase solar system can therefore run a bigger inverter and export more. Exports have a separate limit, set by each network and changing on some, so we keep those in one place: export limits by network.

The panels can be larger than the inverter. Without a battery, the SAA Technical Requirements (version 1.9, February 2026) require the inverter to be at least 75% of the panels’ peak power; with a battery connected, the panels can go further, within the inverter maker’s limit. Our single phase packages have 6.6 kW, 15 kW or 19.8 kW of panels, each with a battery, and your quote names the inverter and its panel limit.

Inverter sizing on the 6.6kW system

Inverter types and sizes

What it means for batteries and EV chargers

Batteries

You don’t need three phase for a home battery. The battery’s inverter counts toward the same per-phase limit as the solar, so on single phase the solar and battery inverters together stay within 10 kW. On a three phase home, a single phase battery inverter connects to one phase and a three phase hybrid inverter spreads solar and storage across all three. Which batteries suit each, and what they keep running, is in three phase batteries and backup; home battery backup explains blackouts on any supply.

Solar batteries we install

EV chargers

SEC Victoria says single phase power supports home EV charging of up to 7.4 kW, and that most EVs sold in Victoria accept 7 or 11 kW on AC. Three phase supports 11 or 22 kW charging, but only if the car can take it, and full 22 kW AC support is not common. Either way the charger needs its own circuit with a safety switch.

Which of our packages suit single or three phase homes

Each of our packages is designed for one supply. Single phase homes choose from 6.6 kW, 15 kW and 19.8 kW of solar with a 12.8 kWh battery; three phase homes from 15 kW, 21 kW and 28 kW with 16 kWh or more. If you have three phase, a 3 phase solar system lets you go bigger, and that page sets out the three phase packages, inverters and batteries. The 15kW solar system comes in both versions.

Compare the packages for your phase

Should you upgrade to three phase?

Usually not for solar alone. Work out how many kW of solar you need first: if it runs on an inverter of 10 kW or less, single phase connects it. The Victorian Government’s Power Up Your Home guide says homes don’t need a 3-phase connection to go all-electric, and that the cost of upgrading to 3-phase power can be very high, especially for existing buildings. It suggests three phase may be worthwhile for homes with very high energy demands, such as workshops running heavy machinery, or for a 3-phase solar system that exports a lot to the grid. If you are building, adding three phase during construction may be more affordable.

Where you need more capacity, a larger single phase connection is often substantially cheaper than three phase, the same guide says. On the CitiPower, Powercor and United Energy networks, an upgrade from single to three phase (up to 80 amps per phase) is a standard connection change, as long as it needs no network works, whether for your connection alone or shared. A licensed electrician arranges it with your distributor and can tell you whether three phase is available on your street and what it costs.

What three phase adds to a solar price

Single or three phase: your questions