Single-phase power uses one active conductor from the street (plus neutral and earth). Three-phase uses three actives and offers more total capacity. Most Sydney houses are single-phase; larger homes and many small commercial sites are three-phase. You can often tell from the main switch and meter. Changing supply type is network and Level 1/2 work arranged through accredited partners — not a DIY board swap.
Think of single-phase as one “push” of electricity into the house. Lights, power points and most appliances run from that one active. Neutral returns current; earth is the safety path. Most Inner West terraces and cottages started this way and still are.
Limits show up when you stack big loads — induction cooking, ducted air-con, an EV charger and workshop tools. A licensed electrician can check how close you are to the main switch rating before you buy more gear.
Three-phase brings three actives, each out of step with the others. Motors can run more smoothly and large loads can be spread so no single active carries everything. Cafés, small factories and some large houses use it.
Having three-phase does not make every circuit three-phase. Most lights and GPOs stay single-phase; only selected circuits use multi-pole protection.
Moving from single-phase to three-phase is a project. The network must allow it, the distributor must approve it, and the meter and consumer mains usually change. Blue Link handles the switchboard side and coordinates Level 1 and 2 work through accredited partners — we do not claim to be your Level 2 provider.
Often the smarter first step is a switchboard upgrade on the supply you already have. For chargers, read single-phase vs three-phase EV charging.
A typical Inner West terrace main switch might be 40–63 A single-phase. That sounds like a lot until you add a 32 A induction circuit, a big air-con, a continuous hot-water load and an EV charger that wants another 32 A. Diversity helps — not everything runs at once — but design still has to be honest about peaks.
Before you buy equipment, send us the nameplate ratings and a photo of the board. Often we can free capacity with a tidy switchboard upgrade, load management on a charger, or by moving a hungry circuit onto a quieter phase if you already have three-phase. Jumping straight to a network upgrade is sometimes right, but it should be the conclusion of a load check, not the opening bid.
Commercial tenancies and warehouse conversions in places like Marrickville, Alexandria and Rosebery are more likely to arrive with three-phase already. Houses in Bondi or Randwick vary block by block. Do not assume your neighbour’s supply matches yours.
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Three-phase boards usually have a main switch spanning three poles and three-pole breakers for big loads. A photo of the meter and board is enough for us to confirm.
Many cooktops run on a dedicated single-phase circuit. Check the appliance sheet before assuming you need a supply upgrade.
It is more capacity, not automatically better. Most homes do fine on single-phase.
Sometimes. It needs network capacity, an application, metering changes and usually a new or modified switchboard. Supply-side work is Level 1 and 2 via accredited partners.
Blue Link Electrical Services · NSW licence 332956C · since 2016 · fully insured
After-hours for genuine emergencies only. Level 1 and 2 supply work arranged through accredited partners.