Do Safety switches really work?

In short, yes - they can work to protect you in many situations. However, there is more to your switchboard than just the safety switch! In the modern household switchboard, there are usually three protective devices for any given circuit: 

• a main switch;
• a circuit breaker; and
• a safety switch.

The main switch

The main switch turns the entire electrical installation on and off. This switch is usually on the far left of the switchboard. It was once only used as an isolating point (turns on and off the electrical installation) as its only purpose. These days, electricians put a circuit breaker in its place and use this circuit breaker to protect the incoming mains to your home or business against overloads that may occur. Put another way, if your home’s incoming “mains cabling” is rated to carry 63 amps, we now protect that cable by replacing the main switch with a circuit breaker rated at 63amps. It’s an additional way a modern electrical contractor can protect your home against the dangers of overcurrent.

The circuit breaker

The circuit breaker is used to protect your home’s wiring against short circuits and current overload. If you have a circuit breaker that is rated at 16amps, it means that the cable that is being used on that circuit is able to carry 16amps. With all of the modern appliances that are being installed in today’s homes, it is easy to overload the circuit. If the circuit is overloaded, the circuit breaker will trip and help keep the electrical installations’ wiring safe, and stop the cable from burning out.

The safety switch

So far we have worked out that the main switch and the circuit breaker are important tools in protecting your home’s wiring… but what about the home owner! This is where the safety switch comes into play.

The safety switch (sometimes called the “RCD” or “ELCB”) is used to make sure that the current going out to a circuit or appliance is the same as the current that comes back. If the power going out is more than 0.03amps different to the power coming back then the safety switch recognises this and trips. So if some of the power goes down to earth and does not return to the safety switch, the safety switch will trip. This is what happens when you have a faulty appliance or sometimes when you get an electric shock.

If these three protective devices are designed and installed by a licensed electrician according to the latest standards and regulations, they form an invaluable tool to protect you and your home from the dangers of electricity.

Although we live so closely to it, we should always remember that electricity is dangerous and can kill even when precautions are taken. Always use a licensed electrician, to help minimise the risks.

Iain Sibbald is the proprietor of Fuse Electrical 0407 816 110 and is a registered electrical contractor.

Important Note: these tips are intended for information only, and should not be relied upon to diagnose or fix electrical issues, nor to inform any kind of electrical installation.  Please call a licensed electrician to carry out all electrical work in your home or business.