Ceramic fuses and old switchboards: what to look for

In most older homes around Melbourne's west, the switchboard sits in or beside the meter box on an outside wall. Newer houses often have it inside, in the garage, laundry or a hallway cupboard, and apartments usually have a small board in the unit. Find yours in daylight and open the door.

That is as far as the inspection goes. Energy Safe Victoria says it is illegal, and potentially fatal, for unlicensed people to do electrical work, even small jobs like changing a power point. Don't unscrew a cover or pull out a fuse carrier for a better view. Photos taken from where you're standing are enough to start with.

Before you study the fuses, use your eyes, ears and nose. Brown or black scorching around a carrier, plastic that has softened or changed shape, a buzz or crackle, or a hot, fishy or burning smell all point to a connection running hot. That doesn't settle down on its own.

Energy Safe Victoria lists sparks from switchboards, switches or power points, along with flickering lights, among the tell-tale signs of faulty wiring. If you notice any of this, close the door and keep people away. Switch off at the main switch only if you can reach it safely without touching anything damaged, then call an electrician.

If there's smoke or fire, get everyone out. Never put water on an electrical fire; for a small one, turn off power to the source if it's safe and use a fire blanket or dry chemical extinguisher.

A rewireable fuse board is hard to mistake. You'll see a row of white ceramic carriers pushed into bases, sometimes with a coloured mark showing the rating. Each carrier holds a short piece of fuse wire that melts when a circuit draws too much current. A newer board has circuit breakers instead: slim devices with a toggle that drops when they trip.

Fuse wire is only as reliable as the last person who replaced it. When a fuse keeps blowing, it's common to find heavier wire fitted to stop the nuisance, and then the cable can overheat before the fuse ever melts. Old carriers also crack and their contacts loosen, and a loose contact makes heat of its own.

There's another reason to leave them alone. WorkSafe Victoria lists fuse blankets and ceramic fuses in switchboards among its examples of asbestos-containing materials.

Fuses and breakers protect the wiring from overload, and Energy Safe Victoria is clear that circuit breakers don't act as safety switches against electric shock. A safety switch does that job: it monitors the current in a circuit and turns the power off within 0.03 of a second when it detects a problem that could put someone at risk.

Energy Safe Victoria says a safety switch always has a test button and 30mA printed on it, so that's what to look for. If nothing on the board carries both, assume those circuits have no shock protection until an electrician tells you otherwise. Old switchboards without a safety switch head Energy Safe Victoria's list of warning signs.

Finding one isn't the end of it. A safety switch only protects the circuits wired through it, and older boards sometimes had a single unit added for the power points while the lights and oven stayed on fuses. If you have them, press each test button every three months, as Energy Safe Victoria advises. If the power doesn't cut, call a licensed electrician.

Look past the fuses to the sheet they're fixed to. Older boards were built on timber, a dark bitumen-like panel or a flat fibre sheet. You can't tell by eye what an old panel contains.

WorkSafe Victoria lists electrical switchboards and their backing boards as a typical location for asbestos-containing materials, particularly in buildings built or renovated before the late 1980s, and names pitch-based switchboards among its examples. Treat an old panel as if it might contain asbestos. Don't drill, screw, sand or scrape it, and don't fix anything new to it.

It's also why an old-board replacement is planned, not squeezed in. WorkSafe's asbestos compliance code says a licensed removalist may be needed if a mounting board has deteriorated or contaminated dust is present, and an asbestos-containing panel that has to come out must be replaced with non-asbestos material. A proper quote says how the panel will be handled.

The board is only the part you can see. Energy Safe Victoria says the wiring should be checked if a house was built more than 30 years ago, and that when buying a home built before the 1980s it's imperative to have it checked before moving in.

Plenty of Melbourne's west fits that description. The Hobsons Bay Planning Scheme ties the growth of Newport and Spotswood to the Federation and Interwar periods, and post-war expansion to Altona and Laverton. Yarraville's heritage precinct is mostly small Victorian and Edwardian houses. When a home like that has been extended, the new circuits are often hung off the original board.

Energy Safe Victoria says fire brigades respond to more than 300 domestic electrical fires each year, many caused by old wiring that has degraded or can't cope with modern equipment. A fuse board feeding a split system, a dishwasher and a home office is that kind of mismatch.

Adding safety switches to a fuse board is sometimes possible, but not always. Consumer Affairs Victoria notes that with older panel-and-fuse or federal fuse boards, an electrician may not have that option and may have to replace the entire switchboard. Once a switchboard is replaced, Energy Safe Victoria's guidance is that the Wiring Rules require safety switches on all final sub-circuits.

The electrician first assesses the board, backing panel, meter box, mains and main earth, and asks what you plan to add. On the day, the supply is isolated, the old gear comes out and a new enclosure goes in. Every circuit is tested before it's reconnected, and one that fails stays off until it's repaired.

A main switchboard is prescribed work, so a licensed electrical inspector has to check it. Energy Safe Victoria says power can't go back onto a new main switchboard until that inspection is done, so ask how it will be arranged. When the work is complete, you must be given a Certificate of Electrical Safety.

Ceramic fuses and no test button are worth acting on, and the timing is largely yours. It moves up the list if you're buying, letting the property, renovating, or adding an induction cooktop, air conditioning or an EV charger. Heat marks, sparking or a burning smell are different: that's a call now.

Total Comfort is a family-run licensed electrical contractor (REC 38187) based in Altona Meadows. We'll look at the board, the backing panel and the circuits, and give you honest advice on whether it needs replacing now or can wait. You get a fixed price for the agreed scope before we start, and quotes are free with no obligation.