When a commercial switchboard needs work
Most switchboard jobs come about for one of a few reasons. The building has grown and the board has run out of room or capacity. A tenancy is being fitted out and needs a new distribution board. An inspection or thermal imaging survey has found overheating or deteriorating equipment. Or the board is simply old, with ceramic fuses, no RCD protection, asbestos backing panels or components that can no longer be sourced.
Common warning signs include nuisance tripping, breakers that feel hot, scorch marks or a burning smell, no spare ways for new circuits and handwritten or missing circuit schedules. None of these should be ignored on a commercial site. A failed board can shut down a whole building.
Not every issue means a full replacement. Sometimes the right answer is replacing a few failed devices, adding a distribution board to take new loads, or upgrading a sub-main. We will tell you honestly which option makes sense, and set out what each one involves, so you can make the call with the full picture in front of you rather than being pushed into the biggest job.
What we do
- Main switchboard replacements and upgrades
- New distribution boards for fit-outs and extensions
- Sub-main upgrades and new sub-mains to tenancies or plant
- Adding RCD protection to final sub-circuits
- Replacing obsolete circuit breakers, fuses and switchgear
- Tenant sub-metering and main metering changes
- Board labelling, circuit tracing and new schedules
- Remediation of defects found during inspections
Design and compliance
A commercial switchboard has to be matched to the building. Before we build or modify one we look at the maximum demand, the prospective fault level at the point of supply, protection coordination and discrimination between upstream and downstream devices, cable sizing to AS/NZS 3008 and room for future growth. Switchboard assemblies are built to AS/NZS 61439, and the installation is completed to AS/NZS 3000.
Where supply capacity needs to increase, or metering changes, we coordinate with Energex in South East Queensland or Essential Energy in the Northern Rivers. Network approvals can take time, so we raise these early. We also check the board location itself, including clearances, access, ventilation and exposure to weather. Salt air along the coast is hard on older enclosures, and it is something we take into account when specifying replacement boards for beachside buildings.
Planning the changeover
For most businesses the biggest concern is downtime. A switchboard changeover usually means a full or partial shutdown, and that needs to be planned with the business owner, building manager or facility manager well in advance.
We do as much as possible before the shutdown. New boards are prefabricated or fitted out ahead of time, cables are run and terminated where they can be, and every circuit is traced and labelled before the power goes off. The changeover itself is then scheduled after hours, overnight or on a weekend depending on the site. For sites that can’t lose power at all, such as those with refrigeration, servers or medical equipment, we can arrange temporary supply or a generator to keep critical loads running.
We also talk through what needs to happen when power returns. That can include restarting mechanical plant, checking fire panels and security systems, and confirming refrigeration and IT equipment come back up correctly.
Testing, documentation and handover
Once the new board is in, we carry out full verification testing before and after energising. That includes insulation resistance, earth continuity, polarity, correct circuit connections, earth fault loop impedance where required and RCD trip testing.
You get:
- A certificate of test and compliance
- Recorded test results for the board and circuits
- Clear, typed circuit schedules fixed inside the board
- Updated single line diagrams or as-built drawings where the scope requires them
Good labelling sounds like a small thing, but it saves time and money every time someone has to isolate a circuit in the future.
What affects the cost
We price every switchboard job individually after a site inspection. The main factors are the size of the board and number of circuits, the fault level and protection requirements, whether sub-mains or consumer mains need upgrading, whether asbestos is present in the old board, network or metering changes, and how much after-hours work is involved. You get an upfront written quote with the scope, assumptions and shutdown plan set out clearly.
Who we work with
We do switchboard work for building owners, facility managers, bodies corporate, property managers, builders and business owners. It often ties in with other work, such as maintenance contracts, fit-outs and EV charging projects that need extra capacity. For houses rather than commercial buildings, see our residential switchboard upgrades page.