Explore our Brand-new Resource Hub & Learn the Basics of Solar & Electrical!
Explore our Brand-new Resource Hub & Learn the Basics of Solar & Electrical!
Posted 1 Feb
Want the latest in energy, solar, and savings?Subscribe to our newsletter – we don’t spam!
Single-phase power delivers electricity through one wire which is standard for most homes in Australia. Single-phase can handle basic
household appliances like fridges and lighting, whereas three-phase power has 3 wires delivering power. Three-phase power is mostly used to
power commercial and industrial buildings to power appliances like EV chargers, ducted air conditioning and heat pumps.
What is Single Phase? In Australia, single-phase (1Φ) is the most common throughout homes and small-businesses. 1-phase runs at 230 V and is capable of running your everyday appliances like washing machines, lighting, fridges, and the most important appliance - the coffee machine.
What is Three Phase? Three-phase (3Φ) is used for properties that require extra power capacity like EV chargers, industrial equipment, and high-consuming appliances in both homes and businesses. 3-phase runs at 400V and is designed to run power-hungry appliances without going over property's maximum capacity.
As Australian property owners continue to invest in their energy, knowing whether your home is single or three-phase can help indicate the best way to upgrade and maximise your power.
| SINGLE PHASE |
THREE PHASE |
|
| Typical Use |
Small-to-medium homes, small offices. | Larger homes, commercial & industrial properties. |
| Good for |
Lighting, fridges, washing machines, and other general appliances. | EV chargers, ducted air conditioning, pool pumps, heat pumps, motors etc. |
| Avg. Upgrade Costs |
$0 |
$4,000-$5,000 - depending on the property and its installation requirements. |
| Standard Voltage (V) |
230 V | 415 V |
| Live Wires |
1 |
3 (120° apart) |
| Est. Maximum Power Draw (63A) | 14.5kW (230V) |
43-44kW |
Courtesy of Connor Lucock on Pexels.
If single-phase is capable of running most appliances, why would you need to upgrade to 3 phase power? Assessing the need to upgrade really comes down to what you need to power.
In a real world scenario, upgrading your home to 3-phase would unlock the ability to charge your electric vehicle faster - from a maximum of 7kW to 22kW.
Upgrading from single to three-phase really comes down to what you're looking to power. The higher power demand, the more power needs to be delivered. 1-ph properties can get away with standard appliances whereas for larger homes, 3-ph will enable more flexibility in your overall capacity.
What happens when you overload a single-phase property? If you overload your property's single phase supply, you'll trip your circuit breaker which will need to be reset.
Real world example: Let's say a standard single-phase, 63A home is running an electric vehicle charger which is charging at a maximum rate of 7.4kW at 32A. This means that the rest of your appliances have to run on the remaining 31A or it will trip the circuit. A ducted air-conditioner consumes around 4-8kW (around 15-20A), and appliances like ovens and kettles run at ~10A meaning that you'll need to keep an eye on what appliances are running at the same time.
(Power was calculated using our Voltage & Current calculator)
Most Australian homes will be on single-phase power, with larger homes and businesses likely to be three-phase.
Here's how you can determine if your property is 1 or 3 phase:
1. Check your smart meter and see how many 'L' icons there are, or if it mentions other details about phases.
2. Inspect the 'Main Switch Grid Supply' and see how many switches there are from 1-3.
In these examples, you can see both single and three-phase property meter boxes and what they look like inside. In the first image, the 3 'L' icons labelling each phase 1, 2, and 3 on the smart meter indicates 3-phase.
The second, mentions '1-phase' in text under the smart meter's screen, and also only has one main grid supply switch.
An electrical phase is essentially a method of delivering power to your property, similar to how a water pipe delivers water. Each phase acts as stream of electricity, and can be upgraded when more power is required.
Australia's AC power supply comes in waves that rise and fall 50 times a second (50Hz), and each of those waves are called a phase.
Using traffic as an example, let's say one lane is open with low to moderate traffic flowing pretty fluently but starts to struggle when heavy traffic appears. This is when three lanes would be more sufficient to allow for the higher demand.
Tip: the symbol for an electrical phase is 'Φ'.
Yes, 2-phase or 'split-phase' electrical power does exist, however only older electrical systems used a form of 2-phase and is almost fully phased-out (pun intended), with modern home electricity supplied as single-phase. Our 2-Phase is not the same as the 120/240V 'split-phase' as the U.S. uses.
In the word of electric vehicle charging, single and three-phase both play an important role in how long it takes to charge EVs.
A Tesla Model 3 electric vehicle has a battery which stores 60kWh of energy. If we charged that car with a single-phase charger which is up to 7kW of power, the EV would take 8.2 hours to charge.
When the house is upgraded to three-phase power, it can deliver up to 22kW of charging to the EV, reducing the charge time to under 3 hours. This upgrade enables the supply to triplicate and provide more power for electric vehicles that have the charging capabilities.
Electric vehicle charging is only one example with other appliances like workshop lathes & compressors, industrial air conditioning, ovens and large electric water heaters.
It's also important to note that if you use all your appliances simultaneosly, you will need the high power output of the three-phase supply.
Not every house or business will need to upgrade to three-phase power, however there are benefits to upgrading your electricity supply which may be worth it depending on requirements and budget.
Upgrading your property to three-phase will allow you to use all your appliances (including heavy consumption) at once without tripping any circuits.
Three-phase is also recommended for high-capacity solar and battery systems.
As there isn't really a fixed price, upgrading to three-phase can cost anything between $4,000 - $5,000 depending on the property and requirements.
Whilst not cheap, upgrading properties to three-phase is more than just adding another connection - elements like switchboard upgrades, trenching, cabling and component upgrades will determine costs which will vary property-to-property.
The advantages of upgrading to three-phase power includes a more
stable and durable form of electricity, the ability to run high-powered appliances without worry, and the capability of installing up
to 30kW of solar.
The disadvantages of upgrading to three-phase power includes upfront costs of upgrading which may not be worth it for some, and can also be more complex for any maintenance.
Finding the right solar and battery system is largely determined by whether your property is single or three-phase power.
Depending on the phase supply, it will impact the maximum solar inverter capacity that you're allowed to install by your DNSP (like Ausgrid). It will also affect your battery configurations and if you'll need to submit additional applications.
In NSW, Distributed Network Service Providers (DNSPs) set limits on the amount of solar inverter output allowed per phase. Ausgrid for example allow up to 10kW of inverter capacity per phase without needing to submit an application.
It's also important to note that if your solar battery is AC-coupled, then the battery's built-in inverter is counted towards the inverter output total.
Three-phase properties on the other hand offer much more flexibility. 3-phase homes with a hybrid inverter can install up to 30kW of inverter capacity which makes it ideal for larger solar and battery systems.
Understanding the differences between single and three-phase can help you make educated decisions for the long term to ensure you're ready to go, and your property is futureproof.
Overall, both single and three-phase setups have their places throughout Australia, with most homes really only needing what single-phase has to offer, and businesses upgrading accordingly. If your property doesn't have to accommodate high-consuming appliances (especially all-at-once), then you should be fine with single phase and won't need to upgrade.
Supply charges, feed-in tariffs, controlled load, peak rates - we explain every line on your NSW electricity bill and show you where you can save more.
Read moreAustralia's Solar Sharer Offer gives households 3 free hours of power from July 2026. Find out how it works and whether solar & battery still makes sense.
Read moreLearn how home electricity works in Australia, including circuits, switches, circuit breakers, RCDs and what happens during power outages.
Read moreRenewable News Articles
We've invested in becoming fully-licenced and qualified installers to ensure Newcastle homes and businesses
get the best systems and installations possible. We want to assist Newcastle's renewable energy revolution with quality systems.
Certified solar system installers near you.
Get CEC-Approved Battery Installations.
Fully-licenced electricians in Newcastle.
Convenient EV charging stations for properties.
Leave a Comment