A commercial switchboard upgrade is rarely just a swap-for-swap exercise. Sub-mains rated for the original 1990s tenancy load no longer suit a fit-out with comms cabinets, a hospitality kitchen, EV charging and rooftop PV. RCD protection that was code-compliant a decade ago no longer is. Energy Safe Victoria audits and insurer inspections increasingly flag boards lacking modern personnel protection, and a fire that starts at an unprotected board can cost far more than the upgrade. Millar Electrics scopes commercial switchboard work end-to-end: distributor liaison, a form-rated assembly supplied to AS/NZS 61439, sub-main and metering coordination, and an outage window planned around your trading hours.
What goes into a commercial board
We design and procure the assembly to the right form rating for the segregation requirement (Form 2 minimum for most commercial; Form 3b/4 where individual functional units must be isolatable for live work). MCBs, MCCBs or ACBs are sized to the load and discrimination plan; Type-A or Type-B RCDs or RCBOs are selected against the downstream loads (Type-B is mandatory ahead of certain solar inverters and EV chargers). Surge protection devices are fitted at the main where the supply is exposed. Every circuit is labelled, the schedule produced, and the single-line diagram updated.
How we handle the changeover
For most commercial sites we plan a single-day outage outside trading hours, typically a Sunday or weeknight after-hours window. The distributor is notified, the meter is removed at the start, the changeover happens against an isolated supply, the meter is refitted and witnessed, and we hand back with everything tested and energised. Critical loads get UPS or generator backstops where the outage window exceeds their tolerance. For larger sites we stage the changeover across multiple visits, isolating one section at a time.
Compliance and handover
All work to AS/NZS 3000 and AS/NZS 61439, with a Certificate of Electrical Safety lodged on completion. We provide as-built drawings, the type-test documentation for the assembly, the new circuit schedule, photographs of every termination, and thermal images taken under load on completion. Records suitable for owners corporation files, insurer audits and ESV inspection.