Touching a live wire can cause a fatal condition in just milliseconds— faster than the fuse or circuit breaker to shut off the power supply.

Such zap from electrical accidents in homes killed 15 people and hospitalised 300 people each year in Australia. On that, many people in Sydney are using a residual current device as a new level of protection from electrical hazards.

A residual electric current device (RCD) is a safety switch that protects you from electrocution and electrical fire. RCDs are tools designed to immediately switch off when it detects unbalanced current in the neutral and energised conductors of wires. 

The imbalance in current happens when electricity leaks through the body of a person who is grounded or accidentally touching live wires. Fortunately, RCD can disconnect the power source rapidly to prevent serious injury from an electric shock. It can quickly cut the power source when your fuses and circuit breaker fails to do so during electrical mishaps. 

Why Do You Need an RCD?

RCD provides a wide array of benefits in your home. It serves a primary means of protection against electrocution and house fires caused by faulty wiring. Moreover, the device can monitor the electric current throughout your home, a piece of equipment or individual circuit.

The safety switch can quickly shut the powers off in case you get electrocuted in wet areas of your home such as the bathroom, kitchen and the likes. Aside from that, the portable type of RCD is a lifesaver whenever you plug electrical items from your home to work. 

Types of RCD

There are two types of RCD: the non-portable and portable version. Each version has different kinds, having advantages and disadvantages when installed in the different parts of your electrical system.

Non-Portable RCD

Non-portable RCD is fixed or installed at the socket outlet and switchboard. Here are the advantages and disadvantages of installing the device in your main switchboard and sockets:

Non-portable RCD installed in your switchboard.


  • Provides permanent protection against fixed-wiring faults and electrical wiring faults
  • Can be installed in new, modified or existing electrical installation


  • A single fault can unnecessarily shut off your entire operation
  • Installation is costly if you need modifications in switchboards
Non-portable RCD in your socket outlet

There should be a label attached when fitting an RCD in your socket outlets, stating ‘RCD protected’ or other indications. The label will tell the person using the sockets that there is a non-portable device fixed in it.


  • Permanent protection against electric shock
  • Protects anything plugged into the socket-outlet installed with the device


  • Protection only applies to wires past the socket fixed with the device
  • It needs RCD replacement when there is damage to the socket-outlet

Portable RCD

You can use a portable RCD in any socket outlet, protecting the equipment plugged into them. Using a portable RCD to circuit or outlets already protected with non-portable RCD has no adverse effect on the operation of either device. The portable device consists of two types, namely: the plug type and stand-alone unit.

Portable Plug Type

The portable type can be plugged into your socket outlet to protect a single piece of equipment. 


  • Protects equipment whether there is RCD protection or not in the circuit
  • Allocated to users rather than to all electrical equipment


  • Doesn’t provide protection from faults in fixed-wiring
  • It requires frequent testing as it’s prone to abuses and damages
Portable Stand-Alone Unit

The portable stand-alone unit RCD is usually incorporated into the power board. Installed in one power board, it can protect multiple socket outlets and equipment connected to it.


  • Greater protection than portable plug type provides
  • Protects multiple outlet sockets from one RCD unit


  • Can’t also provide protection from faults in fixed-wiring
  • Less economical if too many pieces of equipment need protection

Is RCD Easy to Maintain?

Checking the functionality of portable RCD is possible every time you use it. For non-portable or fixed type, the safety switch is in the consumer main marked with ‘T’ or ‘Test’. There is also an additional instruction to it stating ‘test quarterly’.

With such instruction, maintaining a fixed RCD should happen every three months. Clicking the test button will shut down the power supply in your home. In case of malfunction, better seek electricians to help you guide on what to do.


It’s challenging to live comfortably in our homes, knowing that electrical mishaps can happen anytime. In some situations, circuit breakers and fuses take a longer time to shut powers off at times of electrical accidents. With that, using the residual current device serves a personal level of protection from the risks that electricity poses.

But when RCD frequently shuts off the power supply, there’s a more serious electrical problem in your home. On that issue, Gordon Powers comes in to help you. We have licensed level 2 electricians to inspect your safety switch, electrical system down to your switchboards. Our company offers electrical services to make sure you and your family are always safe from any electrical hazards.

Call us at (02) 9199 7480 today, and we’ll help you maintain a home free from electrical mishaps.