The installation and regular testing of residual current devices (RCD) is mandatory for all circuits protecting hostile equipment or a hostile environment. This is according to January 2012’s Model WHS Regulations, put in place to ensure Australia’s workplaces are as safe as possible.
What is an RCD?
Also known as a safety switch, An RCD is a life-saving device. Put simply, it is an electrical wiring device designed to disconnect a circuit whenever an unbalanced electrical current is detected between the active conductor and the neutral (return) conductor.
Why is it mandatory for RCDs to be tested?
There is no doubt that RCDs are brilliant devices which save many lives. The problem is like most electrical or mechanical devices, RCDs are prone to failure. Research has indicated that the failure rate in the range of 3-15%.
RCD’s work on the principle of ‘what goes in must come out’. Under normal circumstances, these two wires carry matching currents. In the case of an electrocution, a properly working RCD will detect the imbalance and act as a circuit breaker, operating (“tripping”) swiftly to cut the supply power. This can prove to be life saving, as even a small leakage current can cause a fatality if the leaking electrical current passes through a person. A current as small as 30mA (0.030 Amps) induced for a fraction of a second can be enough to cause cardiac arrest.
Why do RCDs sometime fail?
- The presence of moisture and contaminants
- Internal components become maligned
- The contact surfaces are disrupted causing ‘contact welding’
- Deliberate shorting out (to prevent nuisance tripping)
There are plenty of good and logical reasons why you should have your RCDs regularly inspected and tested. If you have gone to the effort and cost to have RCDs installed, it only makes sense to make sure they will save a life when called upon.
Where we fit in
Assured Asset Testing will inspect and test your portable and fixed RCDs. For each RCD, an operational trip test is carried out, along with a trip-time test measured in m-Sec to ensure the RCD cuts the power to the circuit within the recommended timeframes. Each m-Sec trip test result is recorded on the report we provide.
What is the legislation on RCD testing?
According to the Model WHS Regulations – January 2012, the installation and regular testing of RCDs is mandatory for all circuits protecting hostile equipment and/or environment.
Click here to download your copy of the Electrical Safety Code of Practice.
Click here to download your copy of the model WHS Act and Regulations
Primary Source – Safe Work Australia
QLD ACT and Regulations can be downloaded here – QLD Electrical Safety Act and Regulations.