Why Do Circuit Breakers Keep Tripping?

Circuit breakers keep tripping because of overloaded circuits or plugging too many high‑wattage appliances, like heaters and dryers, into one outlet. It can also happen because of short circuits, ground faults, or ageing, faulty wiring.

When your circuit breaker or safety switch trips, it means it’s cutting power to prevent electric shock or fire. However, persistent tripping can signal more serious issues.

In this post, we break down why your circuit breaker is acting up, the most common culprits in Australian households, and how to diagnose the issue safely before it leads to a costly repair.

What Does a Circuit Breaker Do (and Why It Trips)?

A circuit breaker is a safety device inside your switchboard. Its primary job is to monitor the flow of electricity and instantly “break” the circuit if the current reaches dangerous levels.

Think of your circuit breaker as the sentinel of your home’s electrical system. Without this humble switch, wires could overheat and melt their insulation. These can damage your appliances or, worse, spark a house fire.

When your circuit breaker trips, it isn’t failing. It is succeeding at its job.

Why Does My Circuit Breaker Keep Tripping?

Now, if your circuit breakers keep tripping, it’s usually because of one of these scenarios.

1. Overloaded Circuits (Most Common Cause)

In Australian homes, overloaded circuits are the most common cause of tripping breakers.

Every circuit in your switchboard has a load limit, or the maximum amount of electricity it can safely carry at one time.

Think of a circuit like a water pipe. If you try to force too much water through at once, the pipe will burst. In your home, the circuit breaker “trips” to stop the “pipe” (your wiring) from melting or catching fire.

Standard power circuits in Australia usually carry a 16 to 20 Amp rating. When the combined “draw” of your appliances exceeds this number, the breaker cuts the power.

Here’s a table showing common household appliances and their approximate amperage:

Now, let’s use it as a reference for your usual “morning rush”. If you turn on a kettle (9A) and a toaster (5A) while a dishwasher (8A) is running on the same circuit, you are pulling 22 Amps.

On a 16A or 20A circuit, your breaker will trip almost instantly to protect your home.

2. Short Circuits

A short circuit occurs when an “active” (live) wire makes direct contact with a “neutral” wire.

In a healthy circuit, electricity flows through an appliance (the resistance). In a short circuit, electricity finds a “shortcut” with zero resistance. This causes a near-instantaneous, massive surge of current that can reach hundreds of amps in a fraction of a second.

This surge generates extreme heat instantly. Without a circuit breaker to “snap” the power off, the wiring inside your walls could melt, ignite nearby insulation, or cause an electrical explosion (arc flash).

Some common culprits of short circuits in Australian homes are:

• Pest Damage: Rodents in roof spaces or wall cavities chewing through cable insulation.
• Failed Appliances: A loose wire inside a toaster or a frayed cord on a vacuum cleaner.
• Degraded Wiring: In older homes, the rubber insulation on “tough rubber sheathed” (TRS) or “virginia” wiring can crack and crumble over time.
• DIY Disasters: Damaging a cable while drilling into a wall or using an improperly wired power point.

With short circuits, your circuit breaker trips immediately, even when nothing obvious is running. It’s not an overload issue. It’s a wiring fault, and it’s safest to have a licensed electrician inspect it.

3. Ground Faults (Earth Faults)

A ground fault, also called an earth fault, happens when a live (active) wire comes into contact with something it shouldn’t. Instead of flowing safely through the circuit, electricity escapes to earth.

This can happen when a live wire touches:

• The ground (earth) wire
• The metal casing of an appliance
• Water or moisture inside a fitting or outlet

Ground faults are especially dangerous because they increase the risk of electric shock. They’re more common in areas where water is present, such as kitchens, bathrooms, and outdoor areas.

Water and metal both conduct electricity, which makes faults more serious in these spaces.

If your circuit breaker keeps tripping and you have an RCD or RCBO, it may be detecting a ground fault. These safety switches are designed to trip instantly when they sense electricity leaking to earth. They act in milliseconds to reduce the risk of shock.

If the power won’t stay on, it’s a sign the fault is still present and needs checking by a licensed electrician.

4. Faulty Appliances or Wiring

Sometimes the problem isn’t your switchboard. It’s what’s plugged into it.

As appliances age, their internal components degrade. Heating elements can crack, motors can seize, and internal wires can vibrate loose.

When an appliance is “faulty,” it usually causes a trip in one of two ways: it suddenly demands a massive surge of power (short circuit), or it “leaks” electricity through its frame (ground fault).

In Australian households, the most common “breaker-trippers” are those that involve heat, water, or high-torque motors:

• The Heat Seekers: Kettles, toasters, and hair dryers. These pull high current, and the constant heating/cooling cycles can cause internal wiring to become brittle.
• The Water Workers: Dishwashers, washing machines, and fridges. If an internal seal leaks onto an electrical component, your RCD (safety switch) will trip instantly.
• The Old Timers: That second fridge in the garage or an old power tool. Ageing insulation can fail, causing “nuisance tripping” that seems to happen for no reason.

If your circuit breaker keeps tripping when you plug in the same appliance, unplug it and have it checked or replaced. Also, keep a “look, listen, and smell” approach. If you notice any of the following, stop using the appliance immediately:

What to Do If Your Circuit Breaker Keeps Tripping

Follow these steps to diagnose the issue safely:

• Step 1. Locate & Identify: Find the tripped switch in your board (often sitting halfway or at “OFF”). Note the label (e.g., “Kitchen”) to identify the affected area.
• Step 2. The Total Unplug: Physically unplug all devices on that circuit. Don’t just turn them off. Remove the plugs to isolate the fault.
• Step 3. The Hard Reset: Switch the breaker firmly to OFF, then back to ON.
  • If it trips immediately: You have a wiring fault. Stop and call an electrician.
  • If it stays on: The issue is likely an appliance. Proceed to Step 4.
• Step 4. The One-by-One Test: Reconnect appliances slowly. If the breaker snaps off when you plug in the kettle, you’ve found your culprit.

When to Call a Licensed Electrician

Under Australian standards (AS/NZS 3000), DIY electrical repairs are illegal. Call a pro immediately if you notice:

• Burning smells, scorch marks, or buzzing sounds.
• Breakers that feel warm or “spongy” when resetting.
• Persistent tripping even with nothing plugged in.

Remember not to replace a defective circuit breaker yourself and let a professional handle the job.

You can also ask the electrician about installing dedicated circuits for major appliances to prevent future overloads. This reduces nuisance tripping, improves safety, and helps future-proof your home’s electrical system.

Act Before a Trip Becomes a Hazard

A tripping circuit breaker is your home’s way of sounding an alarm.

Although turning the power back on might seem like an easy fix, the circuit repeatedly tripping indicates a deeper problem, such as an overloaded circuit, a short, or old wiring. Ignoring these signs increases the risk of electrical fires and permanent damage to your appliances.

If you’ve noticed flickering lights, warm power points, or a breaker that won’t stay reset, it’s time for a professional health check. Book your safety inspection with SBH Electrical and call 0457 759 723.