Every home should have residual current devices, also known as ground fault circuit interrupters or RCDs, installed as part of the electrical wiring system. An RCD provides a critical layer of protection against electric shock that can help prevent serious injuries or loss of life. However, many older homes still lack these important safety devices.

This blog post will explain what an RCD is, how it detects current leaks in appliances and power tools, and why having them in your home electrical system is so important. We’ll discuss the safety risks that RCDs help mitigate, like faulty appliances developing shorts over time. We’ll also look at where different types of RCDs should be installed throughout a typical household.

By the end, you’ll understand why RCDs have become mandatory for new home builds according to electrical safety codes. Their ability to cut power within milliseconds of detecting any current leakage can make the difference between a non-event and a tragic accident. 

Consider upgrading your home’s electrical panel and socket outlets to include RCD protection if you don’t already have it. Your family’s safety is worth the small investment.

What is an RCD?

An RCD, or residual current device, is a safety mechanism that monitors for any unintended current flowing from live conductors to the ground. It works by comparing the currents flowing in an electrical circuit’s live and neutral wires. 

The RCD would be the incoming device feeding the circuit breakers’ electrical supply. If there is an imbalance of 0.03 amps or more, meaning the current is leaking somewhere it shouldn’t be, the RCD will trip and disconnect power within fractions of a second. 


This rapid response is important, as currents over 0.01 amps that humans feel can cause fibrillation of the heart. There are two main types of RCDs – those that protect individual appliances called portable RCDs and whole-home RCDs installed in the main electrical panel that monitors all circuits. 

These are installed in the consumer unit (fusebox) and can protect individual or groups of circuits. They are sometimes called ground fault circuit interrupters, or GFCIs for short.

Why Do You Need an RCD in Your Home?

There are several important reasons why having RCD protection is necessary in residential electrical systems. Traditional circuit breakers and fuses only respond to overloads, not small electric current leaks that an RCD detects. 

However, even tiny leakage currents at low voltages can cause electrical hazards over time or, even worse, electrical fire. Faults can unintentionally develop in wiring, appliances, and tools over ageing and use. 


An RCD provides a crucial safeguard against electric shock if an electrical fault does occur. It helps address situations where traditional overload protection may fail to operate quickly enough, such as when moisture or a metal object connects a live device part to the ground. Proper RCD installation ensures anyone in a home is not exposed to the risks of electrical equipment with isolated or concealed faults.

How Does an RCD Protect You from Electric Shock?

Installing RCD protection at key points throughout a home’s electrical system is important for maximum coverage. At a minimum, experts recommend putting a whole-home RCD or RCD miniature circuit breaker at the main service panel to monitor all circuits.

Due to increased shock risks, additional RCDs or RCD-protected outlets should also be installed near water sources like bathrooms, kitchens, outdoor areas, and basements. Appliance circuits powering clothes washers, dryers or dishwashers are also good candidates. 


Workshops or areas housing power tools could utilise portable RCD extension cords for outdoor usage. Installing RCDs helps satisfy electrical safety codes while providing peace of mind, knowing your wiring is continuously monitored for faults. Under RCD regulations, all residential homes sold or leased in Western Australia need at least two RCDs protecting all power point and lighting circuits.

Where to Install RCDs in Your Electrical System

Homeowners often have questions about installing and maintaining RCDs. Professional electrician installation is recommended for whole-home RCD units to ensure proper wiring. 

Portable plug-in RCD gadgets cost $20-$50, while permanent breakers run $70-$150, depending on your panel brand. Testing should happen monthly by simply pressing the test button – this verifies it will trip if needed. 

If you hold the test button in for a long time and the RCD does not switch off the electricity supply, get advice from a  registered electrician. No routine maintenance is otherwise required beyond occasional cleaning. 

Older homes without RCDs can upgrade specific circuits like hot tubs first before completing the main panel. Leased properties may require landlord approval due to wiring changes. 

Property safety should be the priority as RCD costs are lower than emergency room bills or worse if electrical shocks occur. Placing life-protecting safeguards throughout your household’s electrical system is a worthwhile investment regardless of the setting.

FAQs About RCD Installation and Use

1. How do I test my RCD?

Press the test button, usually labelled, to trip the RCD and ensure it functions properly. The RCD should switch off immediately when tested.

2. How often should I test my RCD?

Most electricians recommend testing your RCD monthly or after power outages by pressing the test button as a basic safety check.

3. Is RCD installation difficult?

Installing an RCD breaker or outlet replacement is relatively simple for a professional electrician. A whole-home unit requires more work but ensures comprehensive protection.


4. Do I need permits to install an RCD?

You usually need permits for whole-home RCD installation or major electrical work. Simple outlet replacements may not require permits, depending on local codes.

5. How long do RCDs last?

Quality RCDs have lifespans of 10-15 years. Consider upgrading older existing RCDs for maximum safety as technology improves. Regular testing helps ensure continued proper functioning.

6. Can I install an RCD myself?

While possible, it’s generally best to hire a licensed electrician for most RCD work to ensure it meets safety codes and your personal protection.

The Importance of RCDs Can’t Be Overstated

Installing RCDs in your home’s electrical system offers an essential layer of life-safety protection against electric shock. As this blog post has discussed, their fast-tripping ability can mean the difference between injury or worse from even minor appliance faults. 

That is why RCDs are now mandatory in new housing construction according to electrical safety codes. For older homes still lacking RCDs, upgrading is recommended wherever possible.

If you have any other questions about RCD installation, maintenance or safety, don’t hesitate to contact the experts at Your Electrical Experts. We can assess your home’s current setup, advise where additional RCD outlets or circuits are needed most, and perform the work to the highest standards. 

Protecting you and your family from the risks of electrical accidents is our top priority. Give us a call today to discuss professionally upgrading your home’s protection through residual current devices. Your safety is worth the investment.