A building has outgrown its switchboard when new equipment draws more load than the board was ever rated to carry. Extra EV chargers, split systems and server racks are common culprits. The warning signs are usually simple: breakers tripping more often, panels running warm or discoloured, and lights flickering when heavier equipment starts up. 

Most building managers don’t think about the switchboard until something trips. That’s usually the problem. A commercial electric service that once had plenty of headroom can quietly slide into overload territory as tenancies grow and equipment piles up. Spotting the signs early keeps the upgrade on a manager’s own schedule instead of the switchboard’s. 

The Warning Signs Most Managers Miss 

The clearest signs of a switchboard under strain are simple to spot. Breakers trip more than they used to, panels run warm or discoloured, and lights flicker when heavier equipment starts up. 

• Breakers tripping repeatedly, especially when specific equipment like a compressor or kitchen appliance switches on 

• A panel that feels warm to the touch, or shows discolouration, scorch marks or a faint burning smell nearby 

• Lights flickering or dimming momentarily when large equipment starts, pointing to voltage sag under load 

• A persistent buzzing or humming coming from the board itself 

• Power points or circuits that seem to lose power intermittently for no clear reason 

Most operators reckon a single trip means nothing. A pattern of trips means the board’s telling everyone something. 

Why Buildings Outgrow Their Switchboards 

Buildings outgrow their switchboards because the equipment plugged into them today draws far more power than the original design ever accounted for. It rarely happens on purpose. It accumulates, tenant by tenant and upgrade by upgrade. 

• EV chargers, which can add anywhere from 7kW to 22kW of continuous draw per unit, are one of the fastest-growing causes of strain in commercial car parks 

• Split system air conditioning added tenancy by tenancy, often without anyone checking the cumulative load against the board’s rating 

• Server racks and IT equipment, particularly where a business has scaled up its tech stack without touching the electrical fit-out 

• Extra tenancies or subdivided floor space, each adding circuits to a board that wasn’t sized for the added density 

• Commercial kitchen upgrades, where induction cooktops and larger refrigeration units draw considerably more current than the gear they replaced 

Many switchboards go in with 20 to 25 percent spare capacity, a common rule of thumb rather than a fixed standard. That board can still end up running close to its rated limit within a decade. That’s especially true in buildings that changed hands or changed use along the way. 

Basic Checks a Manager Can Do Without Opening the Board 

Managers can spot early trouble without opening the switchboard at all. It comes down to watching for patterns in tripped breakers and checking for warmth or discolouration on the exterior. It also means noting when lights flicker as equipment starts up. None of this requires touching the board itself. 

• Keep a rough log of when breakers trip and what was running at the time 

• Look, don’t touch, for discolouration, scorch marks or a burnt smell near the enclosure 

• Notice whether lights flicker or dim when a compressor, lift or other large load kicks in 

• Check whether the switchboard’s asset tag or sticker shows a rated capacity and installation date, since older boards are more likely running close to their limit 

• Pay attention to any power points that cut out under load or feel warm around the faceplate 

This is pattern recognition. Diagnosing the fault itself is a job for a licensed electrician. Boards carry lethal voltages, and only a licensed electrician is legally permitted to work inside one. 

When to Call in a Licensed Electrician 

It’s time to call a licensed electrician the moment any of the warning signs above show up more than once. There’s no need to wait for the switchboard to fail outright. Some situations don’t leave room to wait at all. 

• A burning smell, visible scorch marks or buzzing from the board: treat this as urgent and call immediately 

• Breakers tripping more than once a week, particularly on the same circuit 

• Any planned addition of EV chargers, commercial kitchen equipment, server racks or extra split systems, assessed before installation rather than after 

• A switchboard older than roughly 15 to 20 years that hasn’t had a load assessment against current equipment 

A licensed electrician can run a proper load audit and thermal imaging survey. That picks up hot joints and overloaded connections well before they’re visible or produce any smell. That’s the sort of fault that sits quietly for months before it forces a shutdown. 

What a Professional Switchboard Assessment Involves 

A proper assessment looks at how the board performs under real load right now. It combines thermal imaging, load calculations and physical inspection to build a full picture of its condition. 

• A thermal imaging survey of the board under normal operating load, checking for hot spots at connections and breakers 

• A load calculation comparing actual and projected demand against the board’s rated capacity, worked out against AS/NZS 3000 wiring rules 

• Testing of residual current devices (RCDs) and RCBOs for correct trip times 

• A physical inspection of busbars, terminations and enclosure condition for corrosion, loose connections or past overheating 

• A recommendation on spare capacity, with 20 to 25 percent headroom commonly used as a rule of thumb for future load 

The common line in the trade is that spare capacity is cheap insurance until the day it isn’t. As a rough guide, a full switchboard upgrade on a mid-sized commercial building often lands somewhere between $8,000 and $25,000. That range covers switchgear, labour and any main supply upgrade, and actual quotes vary a fair bit by site. That’s a meaningful outlay, and nobody wants to cop a hammering on insurance excess and lost trade because a switchboard fault turned into a shutdown. 

Frequently Asked Questions 

How Often Should a Commercial Switchboard Be Inspected? 

Many commercial switchboards get a visual check and thermal imaging survey every 12 months as a general guide. A full load review often follows every three to five years, or whenever equipment changes significantly. Buildings with heavier loads, like commercial kitchens or server rooms, often need more frequent checks. There’s no single interval that applies everywhere, so it’s worth asking a licensed electrician what suits the specific building. 

How Much Does a Switchboard Upgrade Cost? 

Costs typically sit somewhere between $8,000 and $25,000 for a mid-sized commercial board. Older buildings needing a main supply upgrade as well can run higher again. The final figure depends on the board’s size, the building’s age and whether council or utility approval is needed. Getting a couple of quotes from licensed electricians is the only reliable way to pin down a number for a specific site. 

Can a Business Keep Operating During a Switchboard Upgrade? 

In most cases, yes, though there’s usually a planned outage of a few hours while the main board is isolated and swapped over. Electricians generally schedule this work outside business hours or on a quieter day to limit disruption. It’s worth discussing timing early so tenants and staff aren’t caught off guard. 

Final Thoughts 

A switchboard rarely announces its limits with anything dramatic until it’s too late to plan around. Warm panels, frequent trips and flickering lights are the quiet signals that something’s changed since the board was last sized properly. Managers don’t need to diagnose the fault themselves, just notice the pattern and get a licensed electrician in before it becomes an emergency callout.