3 phase power installation Sydney — the 2026 cost guide

Standard single-to-three-phase conversion (three-phase already in street): $6,500–$9,500 fully installed. Covers new service line from pit/pole, three-phase metering, consumer mains, POA re-termination, Ausgrid fees and CCEW.

Conversion requiring network augmentation (three-phase not yet at your section): $9,500–$14,000. Adds Ausgrid's augmentation fee for extending three-phase to your street or upgrading the transformer tap.

New three-phase switchboard (almost always paired with conversion): $1,800–$3,500. A single-phase switchboard cannot accept three-phase supply — it must be replaced or fully re-boarded.

Three-phase-ready new build or granny flat: $3,800–$7,500 depending on distance from the network connection point and whether the meter box is at the front boundary or house-mounted.

You need it: 22kW three-phase EV charger, ducted AC over ~14kW, home workshop with 3-phase welder/lathe/compressor, lift or dumbwaiter, commercial kitchen equipment in a home restaurant/fit-out, combined peak load exceeding 100A single-phase.

You probably don't: one 7kW single-phase EV charger, standard split-system AC, induction cooktop and heat pump hot water on their own. Most Sydney homes run comfortably on upgraded 100A single-phase mains.

The grey zone: two EV chargers, EV + heat pump hot water + induction + ducted AC combined. Load calculations decide — we run them on site and give you a written recommendation rather than defaulting to the more expensive option.

Future-proofing: if you're already doing a mains upgrade for other reasons and three-phase is in the street, the incremental cost to go three-phase now is often only $2,500–$4,000 more than single-phase — cheaper than converting later.

Step 1 — site assessment and network check. We inspect the POA, meter box, switchboard, existing cabling, and confirm three-phase is available in your street via Ausgrid's network records. If augmentation is required we quote that as a separate line item.

Step 2 — Level 2 paperwork lodged. Notification of Service Works, contestable/non-contestable classification, metering coordinator submission for the new three-phase NMI. Typical turnaround is 10–15 business days.

Step 3 — planned outage day. Power isolated at the network, new three-phase service line pulled, three-phase metering installed and commissioned, new consumer mains run to the switchboard, three-phase switchboard installed or re-boarded, everything tested to AS/NZS 3000.

Step 4 — reconnection and certification. Notification of Service Works submitted, CCEW issued to you, metering coordinator activates the new three-phase NMI, all paperwork in your inbox before we leave site.

Home renovation adding ducted AC + induction + EV — combined peak load pushes past 100A, three-phase is the safe long-term answer.

Detached workshop or garage with 3-phase welder, compressor and dust extraction — often paired with a submain from the main switchboard to a dedicated workshop board.

New build or knock-down-rebuild where three-phase is specced upfront — always cheaper to do at construction stage than retrofit.

Granny flat with its own NMI drawn off a three-phase supply — gives the main house future capacity without a second network connection fee.

Home business or hydroponic setup with heavy pump loads or industrial refrigeration.

Second EV charger or 22kW charger being added to an existing single-phase house.