Three phase power installation and upgrades
Sometimes you genuinely need it. Often you don't, and someone is about to sell it to you anyway.
What three phase actually gives you
A normal home has single phase: one active conductor delivering around 230V. Three phase brings three actives, 120 degrees apart, giving you roughly 400V between phases and — more usefully — the ability to spread load across three supplies instead of one.
That matters for two reasons. Some equipment simply requires it: three phase motors in workshop machinery, larger pumps, commercial refrigeration, some ducted air units. And some properties need the total capacity: if your combined load genuinely exceeds what a single phase service can carry, three phase is the answer rather than a bigger single phase supply.
What it does not do is make your lights brighter, your appliances faster, or your power bill lower. If someone has told you otherwise, be careful about what else they've told you.
When you actually need it
These are the real reasons. If none apply, you probably don't need it.
You have equipment that requires three phase
Workshop machinery — lathes, mills, larger compressors, commercial saws. There's no way around it. Some can run on a phase converter, but a proper supply is better if you use them regularly.
Call 0422 253 379A large pump, especially on acreage
Bore pumps and larger irrigation pumps are often three phase, and starting current on a big single phase motor is punishing for the supply.
Call 0422 253 379Your combined load keeps tripping the main switch
Ducted air plus pool plus induction plus EV charging can genuinely exceed a single phase service. Load management sometimes solves this more cheaply — worth checking before upgrading.
Call 0422 253 379Two EVs charging at once, fast
An 11kW or 22kW charger needs three phase. Two of them almost certainly does. This is increasingly the reason Hills homes ask.
Call 0422 253 379You're building or substantially extending
If it's going in anyway, doing it at construction stage is far cheaper than retrofitting later.
Call 0422 253 379What three phase costs
Sydney, 2026. The range is wide because the network side varies enormously by property.
| The job | Price |
|---|---|
| Three phase switchboard upgradeWhere the supply is already three phase but the board isn't set up for it | $3,500 – $6,500 |
| Upgrading the supply from single to three phaseLevel 2 service work plus network operator involvement. Depends heavily on what's at the street | $3,000 – $8,000+ |
| Overhead service, existing three phase mains in the streetThe straightforward case | $3,000 – $5,000 |
| Underground service, or where the street has no three phaseCan involve significant network augmentation — sometimes tens of thousands | quote required |
| Three phase circuit to a shed or workshopOnce the supply and board exist, from there it's a submain | $1,200 – $4,000 |
These are indicative market ranges for Sydney in 2026, not a quote. What you pay depends on your switchboard, access and what we find. We confirm a fixed price before starting, and it doesn't move.
How the upgrade actually works
Three phase supply upgrades involve your network operator — Ausgrid or Endeavour depending on where you are — not just an electrician. The sequence is roughly:
- We assess your existing supply, board and actual load.
- A Level 2 Accredited Service Provider submits the application to the network operator.
- The network confirms what's available at your street. This is the step that can change everything — if three phase mains aren't there, the cost can jump dramatically.
- Service mains upgraded, meter changed, switchboard rebuilt for three phase.
- Circuits redistributed across the three phases so the load is balanced rather than all sitting on one.
That last step matters and is often skipped. Three phase with everything wired onto phase A is just single phase with extra copper.
Three phase questions
How much does three phase power cost to install?
If your supply is already three phase and only the board needs upgrading, $3,500–$6,500. Upgrading the supply itself typically runs $3,000–$8,000, and can go well beyond that if the street has no three phase mains and network augmentation is required.
How do I know if I already have three phase?
Look at your main switch. Three phase boards have a main switch spanning three poles, and you'll usually see three fuses or three service cables at the meter. Send us a photo of your board and we'll tell you in a minute.
Will three phase reduce my electricity bill?
No. You're billed for energy consumed, not how it's delivered. Three phase can make some equipment run more efficiently, but it is not a bill-reduction measure and nobody should sell it to you as one.
Can I run three phase equipment on single phase?
Sometimes, using a phase converter or a VFD. It's a reasonable answer for one machine used occasionally. For a workshop used regularly, a proper supply is more reliable and usually works out better.
Do I need three phase for an EV charger?
Not for a 7kW single phase charger, which covers overnight charging for almost everyone. You need it for 11kW or 22kW, and for charging two vehicles quickly at once.
How long does a three phase upgrade take?
The electrical work is usually one to two days. The network application and scheduling in front of it is the long part — allow several weeks, sometimes longer.
What customers say
Jason solved a really complex problem for our house with excellent professionalism and workmanship. Highly recommend, would def work with him again. On time delivery and within budget.
Fantastic service! Friendly, efficient and well priced. Highly recommend. Thank you for swiftly fixing our switches.
Jason onsite quickly and completed the work on the spot, giving us a good price and was very polite. Would highly recommend.
These are Google reviews for our team at Cync Electrical & Automation — the licensed contractor behind Hills Electrician. 5.0 from 20 reviews. — see the profile
Not sure whether you need it?
Tell us what you're trying to run. We'll tell you honestly if single phase will do. Call 0422 253 379.
Get a quote