Why Does My Circuit Breaker Keep Tripping?

Circuit Overload vs Short Circuit: Understanding the Difference

A circuit breaker is a thermal-magnetic safety device designed to protect building wiring from overheating. When a breaker trips, it is doing its job — preventing electrical fires.

Understanding whether you have an overload or a short circuit dictates your next step:

The Thermal Overload

When you run too many appliances at once, the total current draw slowly exceeds the breaker’s rated limit (e.g. pulling 22 Amps through a 16 Amp breaker). The breaker heats up over several minutes until its thermal bi-metal strip flexes and trips the switch.

The fix: Reduce the simultaneous load by unplugging non-essential heating appliances or have an electrician run a new dedicated circuit.

The Magnetic Short Circuit

If an active wire touches a neutral wire inside an appliance or behind a wall plate, hundreds of amps surge through the circuit in a microsecond. The breaker’s internal magnetic coil senses this massive spike and trips instantly with a sharp snap.

The fix: Do not turn the breaker back on until the faulty appliance or damaged wiring has been identified and isolated.

Common Causes of This Issue

1. Circuit Overload Across High-Draw Heating Appliances

Plugging an air fryer, kettle, and electric heater into the same circuit draws over 20 Amps, causing the bi-metallic thermal strip inside the breaker to bend and trip the switch to protect wiring from melting.

2. Direct Short Circuit in Appliance or Wiring

When an active wire touches a neutral conductor directly (often due to damaged appliance flex or a failed motor), massive fault currents flow instantly, causing the magnetic trip mechanism to disengage power in milliseconds.

3. Ground Fault / Earth Leakage (on RCBO Combination Breakers)

Modern combination RCBO circuit breakers trip not only on overload, but also when moisture or insulation breakdown allows current to leak into the earth wire.

4. Aging or Weakened Circuit Breaker

Circuit breakers experience mechanical wear over decades of operation. Frequent tripping degrades the internal contacts, causing the breaker to trip at currents far below its rated capacity.

What You Can Check Safely vs What Requires a Licensed Electrician

✅ What You Can Check Yourself

• Identify which room or appliances lost power when the breaker clicked down.
• Unplug high-draw appliances (kettles, space heaters, toasters, portable AC units) currently plugged into that room.
• Reset the circuit breaker by toggling it all the way down to reset the internal latch, then firmly pushing it up into the ON position.
• If it holds, distribute your high-draw appliances across different circuits in the house.

⛔ Requires a Licensed Electrician (REC)

• Diagnosing breakers that trip immediately with zero appliances plugged into the circuit.
• Splitting heavily loaded domestic circuits by running a new dedicated cable from the switchboard.
• Replacing faulty, buzzing, or physically hot circuit breakers.
• Thermal imaging and maximum demand calculations across the main switchboard.

Under Victorian law, all fixed electrical wiring, switchboard modifications, and power point replacements must be performed by a Registered Electrical Contractor (REC) and issued a Certificate of Electrical Safety (CES).