A sudden flow of electricity or a disparity of power supply can even cause injury or death. When there is an imbalance in current the Residual Current Devices (RCD) switches automatically cuts off the electricity.
RCDs are the safety switches that minimize the chance of any severe electric shock. Even if there is a minor increase in the flow of current in the circuit, their job is to trip and stop the flow of the current into the device. These safety switches are extremely sensitive. But again these switches must be regularly tested to ensure that they are functioning correctly. RCD testing must be completed every six months and documented accordingly.
It is highly recommended that all homeowners should have the devices installed for safety. The cost of installing residential safety switches is nominal when compared to the safety of family members.
A building constructed in the year 2000 should be fitted with two RCDs to be in agreement with the building regulations. The existing buildings cannot be rented or sold without being later fitted with two RCDs.
Rules in Australia
In Australia, all commercial businesses are required to maintain all kinds of electrical safety. Installation of RCD safety switches is one of the major components in maintaining this electrical safety. Once these RCD’s are installed, they need to be tested at regular intervals to ensure that they are working correctly.
There are certain RCD Testing requirements that help the owner maintain safety and compliance. RCD Regulations Australia indicates that you should install at least two RCD safety switches in a building to ensure that the electrical circuits are evenly divided. This not only increases safety by preventing electrocution, but also allows some lights and power to remain in the building, even if there is a partial fault.
Testing requirements
As per the electrical appliance safety program, every RCD used in your workplace must be tested regularly to ensure that they are working properly. The accumulation of grit, or dust, the lack of use or any physical damage can cause the internal components of an RCD to slow down. At times this can even prevent it from tripping, hence regular testing is recommended.
As per the standard set, the maximum tripping time for any Type II RCD should not be greater than 300 milliseconds. which comes to around 0.300 of a second and is actually very fast.
There are two tests that need to be performed regularly:
The Push Button test
It is designed to indicate that the RCD is working. Testing these safety switches is extremely easy. Here, you simply have to push the “Test Button” that determines if the switch is working properly. If it is in ideal working condition then the RCD should trip without any delay. In the case of any malfunction, you should call over an electrician to re-test the device and repair or replace it. This quick and simple technique is normally found in portable RCDs and must be performed daily. However, this technique does not give accurate results and is therefore not very reliable for assessing if the RCD is working correctly.
The Timed Trip test
This is the “applied current” method which is a lot more accurate way of testing RCDs and is a compulsory test in Australia. This method needs both special equipment and expertise. It measures the operating time of the switch when the sudden current becomes equal to the tripping current that passes between the active and protective leads. It has the ability to measure the actual trip time.
The frequency to be maintained
As per the standard set, RCDs should be retested at intervals depending on their use and the environment they are installed. When they are used for commercial cleaning, they should be tested every 6 months. In workshops and similar locations, the duration is every 12 months. In the case of residential facilities and low-risk environments, stretch the tests out to 2 years. Remember, the RCD on your generator must also be tested on a regular basis.
