So what is a safety switch?
If you have had any electrical work done in the last 20 years or have talked to an electrician, then the chances are you have heard of safety switches.
So, what is a safety switch and why do I need one?
To keep it simple, a safety switch is designed to act if there is a dangerous situation where someone contacts electricity at a level that could be fatal. They can also be called earth leakage detectors or residual current devices and while there are variations on the theme the purpose is to avoid electrocution.
Without getting too complicated they simply measure how much electricity goes out into an appliance or connected device and compare it to how much comes back. If there is a difference that is large enough to cause a fatal electric shock, then they activate to shut down the power. They usually act within thousandths of a second and in my experience, you don’t even realise that you were about to be shocked. In short, if a safety switch has tripped to avoid a deadly situation then its likely someone’s life has been saved whether they know it or not.
Why do I need them?
If you think about it they are a little bit like an air bags in cars except that they are more effective because unlike an airbag which tries to reduce the severity of an impact, safety switches completely cut off the power in the event of a fault, so the obvious answer is that they make your home safer and who doesn’t want that?
In the early days these devices were not mandatory and were expensive and so they were limited in their installation. Often houses will have just one covering the power circuits only. The Wiring Rules have changed over the years to make them mandatory for power circuits but since the latest Australian Wiring Rules edition AS3000:2018 in 2018 they are mandatory for all final sub circuits in new installations and are required for switchboard upgrades and power circuit upgrades in existing installations. There are some other rules and regulations around configurations but that is the gist of it all.
If you are doing anything other than maintenance replacing like for like then the circuit protection on your power circuit needs to be upgraded to a safety switch.
Even though there are still circumstances where safety switches are not mandatory I would still recommend to anyone who is doing any work on their home electrical installation, talk to your Electrician about upgrading all your circuits to have the protection of a safety switch.