Promoting electrical safety in all premises
Tuesday, 22 March, 2011
Safety switches are widely recognised as vital to making electrical systems in business and residential premises all over the world. In recent years, safety switches have been mandated by the Wiring Rules for inclusion in all new electrical installations in Australia. But what about existing electrical systems - shouldn’t they be mandated to be equipped with safety switches as well?
Safety switches, or ‘residual current devices’ (RCDs) as the electrical industry refers to them, quickly sense minute amounts of electrical current that flow to earth in the event of an abnormality in a live circuit, like a fault or a human touching it. RCDs are intended to operate within 25-40 milliseconds, before electric shock can drive the heart into ventricular fibrillation, the most common cause of death through electric shock.
These life-saving devices can be easily retrofitted to all electrical installations at low cost. All premises can and should be fitted with them. By simply having RCDs installed in the premises, the number of electrocution deaths that occur each year would be significantly reduced.
Thankfully, many safety regulators and industry associations in recent years have been instrumental in mandating the installation of RCDs.
In Western Australia, the Department of Commerce implemented new RCD regulations in 2009 that applied to people selling or leasing their homes. Every home sold or leased had to be fitted with a minimum of two RCDs, which must protect all power-point and lighting circuits. Where a new tenant takes up residency, landlords will need to install the devices before the lease agreement is signed. However, for homes with a continuing tenancy, landlords have until 8 August 2011 to fit the RCDs.
A 2009 media statement announcing the regulations emphasised the importance of installing RCDs, stating: “In recent years, 23 people have been electrocuted in Western Australia. All of these deaths could have been prevented if RCDs had been fitted to the power-point and lighting circuits.”
In NSW, the state government recently announced that it was making the installation of RCDs mandatory in all business premises, bringing NSW regulations in line with other states and territories in Australia.
Lindsay Le Compte, the Chief Executive Officer of the NSW Chapter of the peak electrical industry body National Electrical and Communications Association (NECA), welcomed this decision, adding: “The decision was made after NECA made submissions on behalf of the electrical industry on requirements of any future national harmonisation of OHS legislation.
“This decision picks up the proposed mandatory requirement for safety switches in business premises contained in the recently released draft of the national model Work Health and Safety regulations. So it is pleasing to see the NSW Government acting early to adopt the current draft proposals.
“The installation of safety switches will make business premises safer and this is the number-one aim of OHS legislation. The electrical industry has known for years the benefits of installing safety switches, and NECA has been leading the call for this commonsense approach to be introduced in NSW.”
But making it compulsory for RCDs to be installed in business premises is only half the battle. While the government had acted to protect the interests of occupiers and employees at business premises, NECA contends that it should also be prepared to mandate additional electrical protection at residential premises. NECA has led the call for the NSW Government to make it compulsory for residential premises to have RCDs installed and to also introduce periodic electrical inspections.
Le Compte said the NSW Government invited submissions earlier this year on a review of the NSW Electricity (Consumer Safety) Act. NECA lodged a submission and recommended the government act to require mandatory electrical inspections for residential premises in the following circumstances:
- At sale or lease of properties;
- At least once every four years for non-residential property and every 10 years for residential premises; and
- At other times when the entity responsible for the electrical installation at premises becomes aware of damage or risk to the installation.
“NECA’s recommendations regarding electrical inspections in residential premises are in line with the position in several European countries and accord with aspects of existing Australian Standards,” Le Compte continued. “If other states can make safety switches mandatory in homes, then I’m sure NSW can as well. And while we are in the process of making sensible updates to electrical safety, the introduction of electrical inspections should be considered by the NSW Government, too.
“The recent home insulation debacle was direct evidence that many homes have the potential to be death traps because of old, damaged or incorrectly installed wiring and electrical devices.
“The government has not acted to address the issue in residential premises as it has done for business premises. It must be remembered that, while the installation of safety switches provides a measure of protection, the Australian Wiring Rules are clear that safety switches are not recognised as a sole means of protection and are intended only to augment other measures of basic protection.
“Homeowners obtain building and pest inspections on a regular basis. Given the real risk to life and property from faulty electrical circuitry, periodic electrical safety inspections make real sense.”
Warnings for electricians
WorkCover NSW recently issued a safety alert for electrical tradespeople, warning of the hazards of neutral conductors. The alert was issued following a recent serious incident, where an electrician sustained an electric shock after cutting into an isolated power cable that became energised via a neutral back-feed on the electrical installation.
Although the power circuit being worked on had been correctly identified and isolated at the distribution board, a number of factors contributed to this incident, including:
- Inadequate testing of the power circuit, by relying solely on the use of a voltage proximity tester, commonly known as a ‘volt stick’;
- Failure to undertake a positive test and verify the absence of voltage on the conductors, by using an alternative test instrument such as a multimeter; and
- The rise in potential to 230 V of the neutral conductor, once it had been cut by the electrician - this electrical safety hazard arose because of an intermixed circuit on the electrical installation.
The safety alert reminds employers and those in control of workplaces that occupational health and safety legislation requires them to ensure that electrical work and electrical testing on an electrical installation is carried out using a safe system of work.
It suggests electrical workers should conduct a site-specific risk assessment and identify the risks associated with the work (including voltages on disconnected neutrals), and use the following control measures:
- Identify the circuits and apparatus to be worked on, and the appropriate sources of power supply;
- De-energise the circuits and apparatus, and isolate from all sources of supply;
- Ensure the supply remains isolated, by locking off and/or tagging the isolator;
- ‘Test before you touch’ - prove and verify the supply is de-energised by using appropriate test methods and approved test instruments, to test for the absence of voltage on all conductors, including the neutral conductor (‘volt sticks’ should only be used as an indicator and should not be relied on to verify if a circuit is energised or de-energised);
- Use appropriate clothing and personal protective equipment; and
- When leaving unfinished work, ensure that it doesn’t present a hazard to others at the workplace.
Electrical tradespeople should note that when proximity voltage testers are used to prove de-energisation, they must be tested for correct operations immediately before use and again immediately after use - particularly if the test result indicates zero voltage - to confirm that the instrument is still working correctly.
Breathing below ground: respirable crystalline silica risk
Many workers are still experiencing high levels of exposure to silica dust. So what level, if...
Selecting the best respirator for the task at hand
It can be challenging for workers to wear negative pressure respirators during the entire...
4 steps to building a smarter and safer construction site
Construction sites often face a range of potential risks — some of which are obvious, while...