Electrical Safety Switch


Electrical Safety Switch

Simply put, an electrical safety switch will save your life. Receiving an electric shock from a circuit that is not protected by an electrical safety switch may be fatal. A safety switch will limit the amount of electricity “leaked” to a level that is not enough to kill you. The amount of current required to kill a human is around 100 milliamps, which is less than the average light bulb uses.

What does RCD stand for

The technical term for an electrical safety switch is “residual current device”, commonly known as an RCD.

What is an RCD

An RCD measures the amps (current flow) going out to the circuit on the active conductor and monitors the returning current on the neutral conductor. If there is a difference between outgoing current and returning current outside of a threshold (usually 30 milliamps) the RCD will operate and break the circuit in less than 300 milliseconds. This means, if you were to receive a shock from an RCD protected circuit, you will not get a shock larger than 30 milliamps and that shock will be less 300 milliseconds in duration. This is less than the required amount to kill the average human.

In schools and hospitals, 10 milliamp RCDs are used, these are more sensitive but can nuisance trip. If you would like the added protection and don’t mind occasionally resetting your RCD, you can request to have 10 milliamp RCDs installed.




In Australia, all new domestic installations must have RCDs protecting all lighting and power point circuits. This does not mean all houses in Australia have RCD protected circuits, older homes may not have RCDs installed.

Regardless of the age of the house, if you are selling or renting your house out, it must have at least 2 RCDs installed.

RCD Switch Identification


Locate your switchboard. lift the cover and you should see a couple of rows of switches and fuses, an RCD will always have a test button on the front. If you are unsure if you have an RCD or not, simply Google any part numbers you can see.


Upgrading to RCDs

If your home does not have RCDs, upgrading can be surprisingly easy regardless of your current installation. Most manufacturers make adapters fit RCDs to older style switchboards and in most cases is not difficult.

Portable RCD

An alternative to having installed RCDs is the use of a portable RCD. Portable RCDs come in a range of shapes and sizes and are even available in a finer tripping 10mA range. The obvious downfall with a portable RCD is the fact that you have to carry it around and plug it in. However, a portable RCD is easier to reset as the switch is located close to where you are working.



RCD boxes are common in the workplace, they provide multiple outlets for workgroups to use multiple appliances at the same time. They allow for easy testing and resetting as some sites require an Electrician to reset RCDs.


RCD Testing

You can do a push button test on your RCDs yourself. Simply push the test button on the front, this should trip the RCD to the off position and the circuit should lose power. If it does not trip, your RCD is faulty. The push button test is not a comprehensive test, an Electrician will have a meter that can time how fast the RCD will trip in a range of different conditions. If you’re not confident with the operation of your RCD or would just like peace of mind, contact Vested Utility now to have your local Electrician do a safety check.


If you have any questions, please contact Vested Utility or leave a message in the comments box below



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