Safety Switch RCD Testing 

One of the most important electrical safety devices in both the home and commercial environments is the RCD. This is the acronym for Residual Current Device. They are sometimes called ELCB’s (Earth Leakage Circuit Breakers) or Safety Switches.

The Safety Switch RCD Testing monitors the flow of electricity through the circuit it is attached to. Should any abnormalities associated with the delivery of an electric shock or fatal electrocution be detected by the RCD, the unit will shut off the power to the circuit immediately to minimize injury.

Testing 

Portable RCD testing is the process of safely “tripping” your RCD to ensure that it will operate quickly should there be an electrical incident. (This is also known as safety switch testing.)

Your device is designed to trip, or switch off all the power to that circuit. Australian and New Zealand standards detail the maximum “trip times” for various RCD’s. A competent technician testing your RCD will be able to determine whether your RCD is tripping quickly enough. 

The quicker a RCD trips, the smaller the electric shock would be sustained by an individual.

Protection

An RCD protects against injury and death caused by electric shock. It works by detecting an imbalance between the outgoing and incoming total current of a given number of circuits. 

It works on the very simple principle that if there is a difference in the electricity coming in against that which is going out, then it must have gone somewhere.

This phenomenon is commonly known as ‘earth leakage’ – (or the ‘Residual Current’ in the RCD’s title). It can be caused by a number of problems including poor electrical wiring and DIY accidents such as drilling through a cable when mounting a picture hook or cutting through a cable with the lawn mower. 

In this type of situation, the electricity must go somewhere and choosing the easiest route can travel through the lawnmower or drill to the human holding them to create a circuit and cause electric shock.

Components

The working part of an RCD is an iron core (called a toroid) one half of which is wrapped by the live copper wire.  The other half is wrapped by the neutral copper wire.

With the physical properties of electromagnetism, the neutral and live cables produce equal and opposing magnetic fields in the toroid which cancel eachother out.

There is a special switch, called a relay which is connected to the toroid via third copper wire. This is sometimes referred to as the ‘search’ or ‘detector’ coil. On normal operations,

no electric current passes through this wire to the relay, because the live and neutral coils are not producing a net electromagnetic field.

Imbalance

In accidental power surges (for example: a lawn mower slices a ground cable), the relay cuts the electric supply. The current in the neutral cable is now greater than that in the live are no longer equal, the detector coil to the relay, causes it to snap open thus cutting power to the electrical system.

An electrical current of just a few milliamps (mA) experienced for just one second is enough to kill most fit, healthy people. 

Required testing

This push button testing of your RCD is also required under Australian Standards that is to be conducted everyon a Companies can have a responsible e staff member or a technician 6 monthly basis. 

This can be completed by the responsible staff member or by the technician you are engaging to complete electrical safety services.

This “Safety Switch” (RCD) needs regular testing and tagging to follow the law with AS/NYZZS.

This is also to ensure it will respond in a fault situation and that it will also respond within the required time frame. Should it not trip in the required time, a fatal and extensive electric shock may happen.

Additionally, WHS Regulations state all businesses must have a RCD protecting all hostile circuits, and that the RCDs must be tested in accordance with AS/NZS 3760:2010. This to be inspected by the ATS and tag your RCDs to ensure that they comply with the standard and safe lives in an emergency situation.

RCD in the workplace

The RCDs and ELCBs are commonly called Safety Switches. These devices can be fitted to your distribution board, or can be portable. Their tasks is to monitor the flow of electricity through your site. 

Should abnormalities associated with electric shock/electrocution are detected, the unit will shut off power immediately to minimize injury.

Electrical circuits in commercial and industrial buildings are uncommonly unprotected by safety switches. Should a fault occur in an electrical appliance when it is connected to a socket outlet that is not protected by an RCD, serious or fatal electric shock could occur. 

If you do not have RCD protection in your workplace, ATS highly recommend you engage a licensed electrician to install RCDs across all circuits in your workplace.

Although  it is mandatory to have RCDs installed on all hostile environment circuits, installing a RCD and ensuring all electrical appliances and RCDs are also inspected, tested and tagged in accordance with AS/NZS 3760:2010. This is deemed the best method of ensuring electrical safety for the workplace.

An RCD is a life-saving device, but it does not completely eliminate the risk of electric shock. It must be tested to ensure it is working within the safety standards.

Portable RCD

Portable RCDs can look like large Powerboards, or can only have one power outlet. They do however have an internal RCD that will trip should any leakage from the circuit occur while in use.

Portable RCD units are recommended to be used when using any tool inside or outside. These devices are designed to trip in a maximum of 30 milliseconds and will most likely save you from electric shock.

Still the portable RCD needs to be tested to ensure that it will respond to a fault situation and that it will also respond within the required time frame. Should the RCD do not trip in the required time, a dangerous and extensive electric accident can happen.