A switchboard checklist for older homes.

If your home in the eastern suburbs was built before about 1990 — which covers a lot of Mitcham, Forest Hill, Vermont and Blackburn — the switchboard is probably the oldest piece of electrical equipment you own. Everything else in the house has been replaced at least once. The board often hasn't.

You can learn a lot in five minutes with a torch and without touching anything. Here's the checklist, roughly in the order we run through it.

First, what you're looking at

The switchboard is where the supply from the street gets divided into the circuits that run your house. If you're not sure what the parts are called — the main switch, the breakers, the safety switches — our switchboard anatomy guide walks through it. The short version: the board's job is to cut power fast when something goes wrong, and everything on this checklist is about whether it still can.

1. Ceramic fuses

Open the board (the outer door only — never touch anything inside) and look at the protective devices. White porcelain wedges with a screw-in or plug-in base, or fuse wire holders you pull out to replace wire in, are ceramic fuses.

Ceramic fuses mean the board predates circuit breakers entirely, which puts it at 40-plus years old. Fuses protect against overloads reasonably well, but they do nothing at all for electric shock — that's what safety switches are for — and a board this old usually has other problems: aged cable insulation at the terminations, heat damage, and no room for modern protection. Ceramic fuses alone are enough reason to start planning a switchboard upgrade.

2. Are there safety switches?

Look for devices with a test button — usually marked "T" or "Test". If every device in the board is a plain switch with no test button, your home has no safety switch (RCD) protection. An RCD is the device that cuts power in a fraction of a second when current leaks somewhere it shouldn't — through a person, for instance.

The Wiring Rules (AS/NZS 3000) have required RCD protection on power and lighting circuits in new work for decades, but plenty of older boards were never retrofitted. If you're not sure whether a device is an RCD or a plain breaker, press the test button: an RCD trips instantly. (A breaker does nothing, which is also your answer.) Our guide to the difference between RCBOs, MCBs and RCDs explains what's what if the board has a mix.

3. Black backing panels that look like compressed cardboard

Many boards installed before the 1990s were mounted on asbestos-containing sheet — often a black, bituminous-looking panel, sometimes a grey fibro-look backing. It's not dangerous sitting there undisturbed, but it can't be drilled, cut or worked on, and it changes what's involved in any upgrade. If your board has this, don't touch it, and mention it when you call — an electrician who knows it's coming plans the job differently.

4. Heat damage and discolouration

Brown or black marking around a breaker or fuse, a melted or deformed plastic body, or a smell like hot Bakelite when you open the door — any of these means a connection has been running hot, usually for a long time. This is the one checklist item that's urgent. A hot connection is an arcing connection waiting to happen, and arcing inside a wooden-framed meter box is how house fires start. If you find heat damage, that moves from "plan an upgrade" to "book an inspection this week".

5. The overcrowded board

Count the circuits, then look at how they're arranged. The tell-tale signs of a board that's grown piecemeal over decades: breakers doubled up on terminals, circuits labelled in three different generations of handwriting, a second small board bolted on beside the first, or an old fuse board with a modern breaker panel grafted onto it.

This is normal history — the house got air conditioning in the 90s, a renovated kitchen in the 2000s, a spa in 2012, and each electrician squeezed in wherever there was room. The problem is that boards run out of room, terminations get crowded, and nobody any longer knows what feeds what. If there's no spare capacity at all, the next addition (an EV charger, an induction cooktop) forces the issue anyway.

6. The earthing

This one you can't fully check visually, but you can look for the obvious. Somewhere near the board there should be an earth electrode — usually a copper-clad stake — with a green-and-yellow cable connecting it to the board. If there's no visible earth connection, or the cable looks cut, corroded or disconnected, that's a finding.

Modern Victorian homes use the MEN earthing system, where the neutral and earth are bonded at the board and tied to the electrode. Earthing is invisible until the day it saves your life, and it's the first thing we test with instruments on any older home — visual inspection only tells you the wire is there, not that it works.

7. The meter and supply side

While you're at the meter box, look at the whole picture. Older overhead service lines with perished insulation, a meter panel that's rotting or separating from the wall, or a point of attachment that's pulling away from the fascia — these sit on the boundary between your responsibility and the distributor's. In Melbourne's east the distributor is AusNet Services, and anything on their side of the metering goes through their processes. A good electrician will tell you which is which rather than quoting you for work that's AusNet's job.

8. Does anyone know what anything does?

Last check, and it's free: open the board and ask yourself whether the labels match reality. If "kitchen power" also trips the garage, or half the circuits are labelled in pencil from 1987 and the other half not at all, the board fails the usability test. Labelling sounds cosmetic until you're standing there at 10pm with a tripped circuit and a fridge full of food.

What a proper inspection adds

Everything above is what you can see. A licensed electrician adds the instrument testing: insulation resistance on the circuits, earth continuity and earth fault loop impedance, RCD trip times measured in milliseconds, and a torque and thermal check on the terminations. That's the difference between "looks okay" and "is okay" — and on a 50-year-old board, we find something that needs attention about nine times out of ten.

If the board fails the checklist

The fix is usually one of two things. If the board is fundamentally sound but missing protection, we can often retrofit safety switches and tidy the worst of it — a half-day job that buys real safety. If the board has ceramic fuses, heat damage or asbestos, a full switchboard upgrade is the right call: a modern panel with RCBO protection on every circuit, properly labelled, with a Certificate of Electrical Safety at the end. Most upgrades are done in a single day.

Need your board looked at? Get in touch — describe what you found on the checklist (a photo helps) and we'll tell you whether it's urgent, and what it'd take to sort it.