What you are looking at
A switchboard is where the power coming into a house is split into separate circuits. The lights in one part of the house run on one circuit, the power points in another, and bigger appliances such as the oven often have their own. Each circuit has a switch on the board.
The board usually sits in a metal or plastic enclosure, often on an outside wall or in the garage. What you can see from the front is one or more rows of switches, sometimes behind a clear or hinged door. That front view is all this guide covers.
Behind the front panel is live wiring. Removing a cover or panel is electrical work, and electrical work in Queensland must be done by a licensed electrician. DIY electrical work is illegal. Look, by all means. Don't unscrew anything.
The main switch
The main switch turns off the supply to the whole house, or to everything that board controls. It is often bigger than the others and is usually labelled "Main switch" or just "Main".
If every light and power point in the house is off at once, the main switch is the first thing to look at. If it is off and you didn't turn it off, something caused that, and it is worth a call.
Safety switches
Safety switches are also called RCDs. They look a little like the circuit breakers beside them but are usually wider, and each one has a small button marked "T" or "Test". A safety switch turns off the power to the circuits it protects very quickly when it detects a problem on them. One safety switch often covers several circuits.
The Electrical Safety Office suggests safety switches on all circuits and testing them every three months (ESO frequently asked questions). Some older boards have no safety switches at all, or only cover the power points.
Two Queensland rules are worth knowing. Rental homes need safety switches on power point circuits within 90 days after a tenancy starts. If you buy a home without a safety switch on the power point circuits, one must be installed within 90 days of the property transfer. Only a licensed electrician can install a safety switch.
Circuit breakers
Circuit breakers are the narrower switches, usually in a row. Each one looks after a single circuit. When a breaker trips, its lever drops to the off position, or sometimes sits part-way, and that circuit goes dead.
Older boards may have fuses instead of breakers: small ceramic holders that plug into the board. They do the same broad job in an older way. Replacing old fuse boards is part of what P4 does under switchboard upgrades.
The labels
Each switch should have a label saying what it controls: "Kitchen power", "Bedrooms lights", "Oven". On a lot of boards the labels have faded, fallen off, or stopped being accurate after a renovation moved things around.
Good labels save time for whoever has to work on the house next, and for you when something trips. If yours are missing or wrong, mention it next time an electrician is working on the board.
The test button
The test button on each safety switch lets you check that the switch responds. Pressing it should make the switch trip and cut power to the circuits it protects. You then switch it back on. The Electrical Safety Office suggests doing this every three months.
Expect clocks on the oven and microwave to need resetting afterwards. If a safety switch doesn't trip when you press its test button, call a licensed electrician.
When to call an electrician
- A safety switch or breaker trips again straight after you switch it back on, or keeps tripping
- A safety switch doesn't trip when you press its test button
- There is a burning smell, scorch marks, buzzing or heat around the board
- The board has no safety switches, or only some circuits are covered
- You are planning a renovation or an EV charger and the board looks full
- The labels are missing and nobody can tell which switch does what
If you notice burning, scorching or heat, keep away from the board and call an electrician. Don't touch it to investigate.
A clear photo of the closed board, taken straight on from the front, helps us see what we are dealing with before we quote. For tripping and faults, see home maintenance and repairs. For a board that needs replacing or more room, see switchboard upgrades.
P4 works Monday to Friday, 7am to 5pm. After-hours work can't be promised.