RCD vs Circuit Breaker: What’s the Difference?
When it comes to electrical safety, two essential devices often come up in conversation: Residual Current Devices (RCDs) and circuit breakers. While both play critical roles in protecting people and property, their functions vary. Understanding these differences is key to ensuring your home or workplace meets Australian safety standards and provides optimal protection against electrical hazards.
In this blog, we’ll explore the purpose of RCDs and circuit breakers, how they differ, and why both are crucial for a comprehensive electrical safety system.


What Is an RCD?
An RCD, or Residual Current Device, protects people from the risk of electric shock or electrocution. It works by monitoring the electrical current flowing through a circuit.
The RCD quickly shuts off the electricity supply when it detects an imbalance, like a current leaking to earth from a fault or someone contacting live wiring. This instantaneous action can prevent serious injury or even save a life.
Key Features of RCDs:
- Detects residual (leaking) current as low as 30 milliamps.
- Cuts off power in milliseconds, reducing the risk of electrocution.
- Mandatory in Australian homes and workplaces under current electrical standards.

What Is a Circuit Breaker?
A circuit breaker protects electrical systems and appliances from damage caused by overcurrent or short circuits.
Overcurrent occurs when too much electrical current flows through a circuit, often due to overloaded power points or faulty wiring. This can generate excessive heat, potentially leading to electrical fires. Circuit breakers automatically trip to cut the power, preventing damage to your wiring and devices.
Key Features of Circuit Breakers:
- Protects against overcurrent and short circuits.
- Prevents overheating and electrical fires.
- Can be reset manually after tripping, unlike traditional fuses that require replacement.

RCD vs Circuit Breaker
The key difference between an RCD and a circuit breaker lies in their purpose:
- RCD: Protects people from electric shock or electrocution by detecting leaking current.
- Circuit Breaker: Protects electrical systems and appliances by cutting power during overcurrent or short circuits.
In essence, RCDs focus on personal safety, while circuit breakers prioritise property and equipment protection.

Why Do You Need Both?
RCDs and circuit breakers address different risks, making both necessary for a complete safety solution:
- Protecting People: RCDs are crucial for preventing electric shocks by responding to leaking currents that could otherwise harm individuals.
- Preserving Property: Circuit breakers stop dangerous electrical faults, such as excessive current, from damaging wiring and causing fires.
If either device is missing, your electrical system has vulnerabilities. An RCD won’t respond to the excessive load from too many devices plugged into one outlet, and a circuit breaker won’t detect a fault that results in current leakage.
What about RCBO’s?
For those looking for a more streamlined solution, RCBOs (Residual Current Circuit Breakers with Overcurrent Protection) combine the functions of both RCDs and circuit breakers into a single unit. These devices protect against both current leakage and overcurrent, making them an efficient option for modern electrical systems. By using RCBOs, you can enjoy comprehensive protection while saving space in your switchboard.

What Do Australian Standards Require?
In Australia, electrical systems must meet strict safety standards to protect people and property. The AS/NZS 3000 Wiring Rules mandate the installation of RCDs in homes and workplaces, providing crucial protection against electrical shocks. Modern switchboards also include circuit breakers as a standard feature to guard against overcurrent and short circuits, ensuring comprehensive safety coverage.
For enhanced convenience and efficiency, some modern systems use RCBOs, which combine the functions of RCDs and circuit breakers into a single device. This integrated option is gaining popularity for its space-saving design and ability to address multiple risks.
Whether your system uses separate RCDs and circuit breakers or adopts the streamlined approach of RCBOs, having these devices installed and regularly maintained ensures compliance with Australian regulations. It also guarantees your property is equipped to handle a wide range of potential electrical hazards, offering both safety and peace of mind.

How to Ensure Your Property Is Protected
Electrical safety starts with making sure your switchboard is equipped with both RCDs and circuit breakers. These devices work together to protect against electrical hazards, so it’s vital to check that your system is up-to-date and functioning properly.
Inspect Your Switchboard
Look inside your switchboard to confirm that both RCDs and circuit breakers are installed. RCDs typically have a test button, while circuit breakers are identifiable by their switches that trip during faults. If you’re unsure what to look for, it’s best to consult a licensed electrician like any of our team at PWA Electrical Services. We can conduct a thorough electrical inspection, identify potential risks, and recommend any necessary upgrades.
Test Your RCDs Regularly
Testing your RCDs is simple and essential for ensuring they’re working correctly. Press the ‘test’ button every three months. When functioning properly, the RCD should trip and cut off power immediately. If it doesn’t respond as expected, contact a licensed electrician to inspect or replace the device.
Upgrade Older Switchboards
If your switchboard is outdated or relies on fuses instead of modern circuit breakers, it may lack the protection needed to comply with Australian standards. Upgrading to a modern switchboard equipped with RCDs and circuit breakers will enhance safety, improve reliability, and reduce the risk of electrical hazards.
Schedule Professional Maintenance
Even the most advanced electrical systems require regular care. Licensed electricians, like our team at PWA Electrical Services, can perform routine inspections, test RCDs and circuit breakers, and identify potential issues before they become serious. Annual maintenance ensures your system remains safe, compliant, and efficient.
Think About Additional Safety Measures
While RCDs and circuit breakers are essential, a few additional upgrades can further enhance your safety and peace of mind:
- Surge protection devices safeguard your appliances and electronics from damage caused by power surges, especially during storms or grid fluctuations.
- Smoke alarms provide critical early warning in the event of a fire. Hardwired models are more reliable than battery-operated ones, but regular testing is key to keeping them effective.
- Energy audits help uncover hidden risks like overloaded circuits and improve energy efficiency, ensuring your system runs safely and cost-effectively.
Together, these measures create a robust safety system for your home or workplace.
Understanding the difference between a RCD vs circuit breaker and how they work together is essential to keeping your property safe from electrical hazards. At PWA Electrical Services, we specialise in ensuring your electrical system is up to standard and fully protected.
Our expert team installs, inspects, and upgrades systems, ensuring your RCDs and circuit breakers function correctly and comply with Australian regulations.
Get in touch with us today to ensure your RCDs and circuit breakers are performing at their best, providing your property with the reliable protection it deserves.