The short answer
Three-phase power is a supply with three active phases instead of a single phase. It is used where there are big loads such as irrigation pumps, workshop machinery, large motors, big air conditioning plant and faster EV chargers. In NSW, supplies up to 100 A per phase can be single, two or three-phase, but anything above 100 A per phase must be three-phase. Getting three-phase connected, or upgrading to it, involves Essential Energy and an Accredited Service Provider (ASP) for the work on the service line and meter, plus a licensed electrician for the switchboard and wiring inside your property.
Single-phase vs three-phase in plain terms
A single-phase supply has one active conductor and a neutral. A three-phase supply has three actives and a neutral. Your switchboard can then supply single-phase circuits from any of the three phases, and three-phase circuits that use all three at once.
What that means in practice:
- More capacity. A three-phase supply can carry more total load than a single-phase one.
- Three-phase equipment. Larger motors, pumps, compressors and welders are often made to run on three-phase.
- Load spread. Single-phase loads can be shared across the phases. The Service and Installation Rules of NSW say phase imbalance must not exceed 25 A, so circuits need to be balanced sensibly when the board is set up.
Who needs three-phase in the Riverina
Three-phase comes up often around Wagga and the Riverina because of the kind of work done here:
- Farms: irrigation and stock water pumps, grain handling, shearing sheds and workshops. Around the Murrumbidgee Irrigation Area towns like Leeton and Narrandera, irrigation pumps are common.
- Workshops and sheds: welders, compressors, lathes, hoists and other machinery. See our sheds and workshops service and the guide to running power to a shed.
- Industrial and commercial sites: places like the Bomen industrial area in Wagga, and timber and paper industries around Tumut.
- Larger homes: big ducted air conditioning, or a fast EV charger. A three-phase EV charger is typically 11 to 22 kW, compared with about 7 kW on single-phase. Our guide to single vs three-phase EV chargers explains whether that extra speed is useful.
If you are only running a few lights and power points in a shed, single-phase is usually enough. Three-phase earns its keep when you have equipment that needs it, or loads too big for one phase.
The rules for getting three-phase
The Service and Installation Rules of NSW (April 2026 edition) set out what Essential Energy needs before it connects or changes a supply. The key points:
| Rule | What it means |
|---|---|
| Up to 100 A per phase | Supply can be single, two or three-phase |
| Above 100 A per phase | Supply must be three-phase |
| Phase imbalance | Must not exceed 25 A |
| Application for connection | Needed in writing when an alteration would raise maximum demand above your existing connection agreement, or equipment would put significant load on the network |
| Maximum demand calculation | Must be done to AS/NZS 3000 and included in the application |
Adding big loads like irrigation pumps or new sheds is exactly the kind of change that may need a connection application to Essential Energy.
Who does what
A change from single-phase to three-phase, or a bigger supply, is split between different people:
- Essential Energy is the network. It assesses the connection application and decides what the network can supply.
- An Accredited Service Provider (ASP) does the work on the network side. In NSW, only ASPs can carry out new or altered service lines, supply upgrades and similar work, under the Electricity Supply Act 1995. Level 2 ASPs install and connect the customer's service line and do the work at the main switchboard connection, including the service fuse and meter.
- A licensed electrician does the work inside your property: the switchboard, the main switch, the circuits, and wiring to sheds, pumps and machinery, then tests it and lodges a CCEW.
Customer-funded contestable work can only be done by an ASP you choose, and you pay the ASP directly. The NSW Government suggests getting quotes from at least three ASPs.
At NAF Electrical, we don't do Level 2 ASP work. We do the electrical work on your side, help work out your maximum demand, and coordinate with the ASP so the two halves line up.
On farms: private poles and lines
If your property has private poles and lines beyond the connection point (on rural properties, typically the first pole on the property), those belong to the property owner, who must maintain them. Maintenance of a private pole connected to the network has to be arranged with the distributor or an authorised ASP. Essential Energy recommends having private poles and lines inspected by a qualified contractor every year before bushfire season and after major storms. See our guide to private power poles.
What affects the price on our side
Our side of the job is the work inside your property. What it costs depends on what's involved:
- Switchboard upgrades are priced mainly by circuit count, and a three-phase main switch costs more than a single-phase one;
- test and tag is priced per item, and three-phase items cost more than standard plug-in gear;
- EV chargers are install only (you supply the charger), with switchboard work and long cable runs quoted separately;
- fault finding on three-phase gear is charged on time.
Use the switchboard estimate, test and tag estimate or EV charger estimate for your setup. For new supplies to sheds, pumps or workshops, call Nelson or send the job through for a written quote. ASP and network charges are separate and come from them. For rural work generally, see our rural electrical service.
Common questions
Do I need three-phase power?
You need it if your supply would go above 100 A per phase, or if you have equipment built to run on three-phase. Many homes run happily on single-phase. Farms, workshops and businesses with pumps, motors and machinery are more likely to need three-phase.
How do I get three-phase power connected?
It usually starts with a maximum demand calculation and, where needed, an application for connection to Essential Energy. A Level 2 ASP does the service line, service fuse and meter work. A licensed electrician does the switchboard and wiring inside the property and lodges the CCEW.
Can any electrician upgrade me to three-phase?
A licensed electrician can do the switchboard and wiring inside your property. The service fuse, meter and service line work must be done by an Accredited Service Provider. Some electricians are also ASPs, but not all.
Is three-phase better for an EV charger?
Only if your car's onboard charger can use it. Three-phase chargers are typically 11 to 22 kW, but the car sets the actual charging rate. No NSW rule we have found requires three-phase for a home EV charger.
Does three-phase power cost more to run?
Ask your electricity retailer about tariffs for your supply. The cost of the power you use depends on your retailer plan, and the setup cost depends on the network, ASP and electrical work involved.