Over 100A Three Phase in Sydney: The Endeavour Energy Approval Process Explained

Endeavour Energy covers Greater Western Sydney, the Blue Mountains, the Illawarra and the Southern Highlands — and like every NSW distributor, it has a formal approval process for any connection needing more than 100 amps per phase. There's also a lower trigger worth knowing about: loads above 63A three phase can already move you out of a simple, fast-tracked connection into a Standard Connection Service with more paperwork.

Here's what actually happens when a Sydney property in Endeavour's network needs a supply upgrade beyond 100A three phase.

Why over 100A (and over 63A) changes things with Endeavour

Since 3 May 2020, Endeavour Energy requires main switchboard information to be submitted and approved before it will connect any new or upgraded installation rated above 100 amps, in line with section 4 of the Service and Installation Rules of NSW. The required document is the Compliance Statement for Main Switchboards Greater Than 100 Amps, completed by the switchboard manufacturer and lodged, along with supporting drawings, to inspection@endeavourenergy.com.au.

Separately, loads above 63A three phase (or 100A single phase) can be assessed as needing a Standard Connection Service rather than the simpler Basic Connection Service — which applies if Endeavour determines the existing network can support the load without extension works. If it can't, you're into a full connection offer with network-side works, cost estimates, and a longer timeline.

Step 1: Establish the actual maximum demand

Everything starts with a number. For new work, a Level 3 ASP designer calculates maximum demand using AS/NZS 3000 Appendix C. For an existing building considering EV chargers, solar, a kitchen upgrade or added air conditioning, power logging — a Fluke or Dranetz logger left on the switchboard for one to four weeks — gives Endeavour real measured data instead of a conservative theoretical figure, which often means a smaller, cheaper upgrade than the paper calculation suggests.

Step 2: Check capacity in the street

Endeavour needs to confirm the local transformer and street mains can actually carry the extra load before approving anything. This is where the Basic vs Standard Connection Service distinction gets decided — if the network needs augmentation to support your site, that's a Standard Connection Service with its own quote and program, not a same-week approval.

Step 3: Submit the connection application

The application goes through Endeavour's connections process with the maximum demand figure, site details, and proposed load. For anything beyond a straightforward residential job, this is usually run by a Level 2 ASP electrician working with a Level 3 ASP designer, since Endeavour expects supporting technical documentation, not just a request form.

Step 4: Design and submit the switchboard

The main switchboard is designed to meet Endeavour's requirements and AS/NZS 3000, and the Compliance Statement for Main Switchboards Greater Than 100 Amps is completed by the switchboard manufacturer and submitted with the design pack to inspection@endeavourenergy.com.au.

Step 5: Get switchboard design approved

Endeavour reviews the submission before the switchboard can be procured or built. Incomplete compliance statements, missing manufacturer sign-off, or single line diagrams that don't match the proposed load are the most common reasons a submission bounces back — and each round trip typically adds two to three weeks.

Step 6: Installation

Once approved, the switchboard is manufactured to the approved design and installed, along with consumer mains, metering, and any network-side connection work carried out by a Level 1 ASP electrician.

Step 7: Inspection

Endeavour or its appointed inspector checks the finished installation against the approved design on site before energisation — confirming nothing changed from the approved drawings during the build.

Step 8: Testing

Protection settings, earthing, insulation resistance and metering are tested and documented, and phase balancing is confirmed for multi-tenancy or commercial sites.

Step 9: Commissioning

The site is energised, metering confirmed live, and the connection formally handed over as compliant with Endeavour's requirements.

How long does this take with Endeavour?

A clean residential or small commercial upgrade with a straightforward Basic Connection Service typically runs four to eight weeks from application to commissioning. Anything requiring a Standard Connection Service — because the street network needs augmentation — can run considerably longer, so it pays to find this out at the application stage rather than after ordering a switchboard.

Where projects usually get stuck

• Assuming a >100A connection is automatically a Basic Connection Service without checking network capacity first.
• Submitting the Compliance Statement for Main Switchboards without manufacturer sign-off, which Endeavour will reject outright.
• No maximum demand data behind the application — either a proper Appendix C calculation or a power logging study.
• Ordering switchboard hardware before the design is actually approved.

HDE manages the full Endeavour Energy connection process

High Demand Electrical is Level 1, Level 2 and Level 3 ASP accredited, so we handle this process end to end across Endeavour's network — from power logging or max demand calculation, through switchboard design and approval, to installation, inspection, testing and commissioning.

If you're planning a supply upgrade beyond 100A three phase in Western Sydney, the Illawarra, or the Blue Mountains, get in touch and we'll scope the application before you commit to hardware.