RCD Testing – What You Need to Know

What Are RCDs?

RCD stands for residual current devices and are an essential safety feature in every home or property. RCDs monitor the flow of electrical current from the main switchboard. If an RCD detects an imbalance in the current, it will shut off the electricity supply to the power and lighting circuits it regulates.

RCDs will allow the remaining power in the building to stay on if you have multiple RCDs installed.

You can usually find your RCDs in the main switchboard of your building.

Why Are RCDs Important for Your Property?

Resistant current devices are also known as safety switches because their primary function is to prevent electrical shocks, electrocution, and electrical fires. RCDs are designed to protect you from injuries while fuses and circuit breakers are designed to detect an overload and reduce damage to the building and or appliances in use.

Why Do I Need More Than One RCD in My Building?

One of the main reasons for having more than one RCD in your building is to allow the circuits to be equally divided so other lights and power outlets will continue to operate if one device shuts off the electrical supply. Having more RCDs installed means more appliances are protected and there is less of a chance of the RCDs being tripped.

Why Do I Need to Test My RCDs?

The testing of RCDs is an important part of ensuring RCDs are properly installed to ensure they operate correctly. As an owner or tenant of the building, you are responsible for ensuring RCDs are tested at regular intervals.

The regular testing of RCDs is performed because dust, dirt and lack of use can cause the internal components to fail or stop working correctly and may even prevent it from tripping when an imbalance of current occurs.

It’s important you test your RCDs to ensure any broken RCDs are repaired or replaced to prevent injury and property damage.

How Do I Test My RCDs?

The testing of RCDs is a simple process and involves two types of tests that need to be performed.

The RCD push button test

The RCD “push button” test is a quick and simple test to determine if your RCDs are working correctly. The testing of RCDs is easy as all RCDs have a built-in test button.

To test your one of your RCDs, all you need to do is push the test button on the front of the device quickly and then release it. Your RCD should trip without delay, turning off all electricity protected by the RCD you are testing. This means the test was successful and your RCD is working.

The RCD “push button” test will only work on an RCD whose electricity supply is connected, so ensure you have it turned on before you start the test and turn off all electrical devices like computers and TVs. To restore power that has turned off during the test simply turn the “on/off” switch back to “on”.

The trip time test

The “trip time” test is a far more reliable method of assessing the state of your RCDs. This test must be performed using equipment that is able to accurately measure the actual trip time of RCDs and is usually completed by an electrician.

If you have done the “push button” test already and your RCDs didn’t trip, your RCDs will need an electrician to test them for you.

What is the Recommended RCD Testing Frequency?

To ensure that RCDs installed in your property function correctly and continue to do so, they must be tested at regular intervals by you, the property owner or tenant.

The testing frequency of your RCDs is recommended to be completed at least every three months but can be done sooner. This is to find any faults with your RCDs quickly and return them to operating appropriately.

RCD Testing Standards

In Australia, all businesses are obligated to maintain electrical safety. An essential aspect of electrical safety is the installation and testing of all RCDs. Once RCDs have been successful installed by a licensed electrician, you can begin following the testing standards for your RCDs.

RCD testing standards can vary by county and even state and are based on the size of your building and the electrical current flowing to each RCD installed. Failing to comply with these standards can result in you receiving substantial fines. 

What Are the RCD Testing Requirements in WA?

The testing requirements for RCDs in WA dictate that all RCDs in a building must be regularly tested to ensure they operate successfully. These requirements exist to help you maintain safety and compliance standards while you occupy a property.

As an owner or tenant of a property you need to follow RCD testing requirements by performing “push button” tests at regular intervals and calling a licensed electrician when these tests fail, or your RCDs experience faults.

When Should I Have My RCDs Tested by an Electrician?

Occasionally your RCDs will need to be checked for testing by a professional electrician even after you have tested it yourself.

A thorough examination by a specialist will need to be performed to find any broken components that need to be repaired or replaced.

You should have your RCDs and even wiring checked by a licensed electrical contractor if:

  • You need an RCD installed
  • An RCD trips more than once for no obvious reason
  • An RCD fails to trip when you are testing it or resetting it
  • An RCD is tripping slowly and with delay
  • Any power points or light switches are still on after you do an RCD test


If you notice any of the following signs, get in touch with the experts at KNP Electrics to get your RCDs professionally tested.

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