Over the past century, huge progress has been made in the safety and manufacturing standards of cables, but many homes in Melbourne still have old, dangerous electrical wiring installed.
If your home has cabling that doesn’t meet current electrical safety standards, it may need rewiring to ensure your safety and that of your family. If your home was built before 1980 and you’re not sure which type of cable is in it, call your local trusted electrician, Kenner Electrics, to book an inspection.
Lead Sheathed Cable – 1880s to 1910s
Lead-sheathed cables were installed in some homes and government buildings in Melbourne from the 1880s through to the 1910s. Our electricians found this type of cabling in the roof of an old terrace house in Armadale, and it’s likely to still be in use in a number of homes throughout the inner suburbs of Melbourne, where very old houses are common.
This type of cable is a lead outer sheath surrounding cables insulated with bitumen and chemically soaked paper. As the first type of electrical cabling ever installed in Victoria, lead cabling is well past its use date and should be replaced.
The dangers involving lead-sheathed cable are that when the inner insulation crumbles, then the outer lead sheath could come into contact with the inner conductors. This causes the lead to become live, creating a risk of electric shock and a fire risk. There are also additional hazards associated with lead exposure.
Vulcanised Indian Rubber (VIR) Cable – 1910s to 1950s
Vulcanised Indian Rubber (VIR) cable is a copper conductor that is insulated with vulcanised rubber. The rubber insulation is then covered with a wax-impregnated cotton sheath to protect the cable from moisture damage. The VIR cabling was often installed in timber ducting, or a metal conduit, and a bare earth cable may have been run alongside the VIR cable.
VIR cable was most commonly installed in Melbourne between 1910 and 1950. Our electricians encounter this type of cable almost every week, but it is most common in some of the older suburbs we service, such as Hawthorn, Kew, Balwyn, Camberwell, and Surrey Hills.
Unfortunately, our electricians too often find homes where previous electricians have joined these crumbling old cables when they install new power points and light fittings. This can be very dangerous and puts the home and occupants at risk of fire or electric shocks. It’s important to have a good local electrician that you can trust to provide you with the right advice and information about the safety of your home electrical system.
The age of this cabling means that it is unsafe, and the whole house will usually need to be rewired with modern, safe TPS cabling. This is because the rubber insulation deteriorates over time due to exposure to oxygen. As the rubber dries out, it becomes brittle and can easily flake off or crack, leaving exposed live conductors in the roof or walls of your home.
This is particularly dangerous for anyone who enters the roof space or comes into contact with any cabling (e.g., during renovations), as there is the risk of electric shock. If undiscovered, these exposed conductors can also cause arcing, which can result in fires.
Even if the insulation surrounding the cable has not visibly crumbled, it is unsafe to alter the circuit or reconnect the cables to a power outlet or light switch, as disturbing the cable can break down the insulation and expose the live cables.
In many cases, the timber ducting that the VIR cabling was installed in will have rotted or splintered, so it is very easy to break if someone is moving around the roof space. This could disturb the rubber cables that are in the ducting and cause the insulation to crumble. Rubber cabling that was installed in metal conduits is not any safer because if the insulation has deteriorated, then the conductors may come into contact with the metal, causing the whole conduit to live!
As the VIR cable does not have an integrated earth cable, it relied on a bare earth cable to be run alongside. This earth cable can be easily disturbed or broken by people in the roof space or during renovations, leaving your lighting or power circuit without earth protection.
Tough Rubber Sheathed (TRS) Cable – 1940s to 1960s
From the 1940s to the 1960s, another type of rubber cabling was also commonly installed in Melbourne: tough rubber sheathed (TRS) cable. This cable has copper conductors surrounded with rubber insulation. It was installed in a similar fashion to modern regulations, except it often did not have an earth cable.
Commonly, an un-sheathed bare-earth cable was installed throughout the home, and this was then connected as required. This is no longer permitted, and new safety regulations require each electrical circuit to have its own independent earth cable to prevent the accidental disconnection of the protective earth from all circuits. Earth cables now also need to be sheathed.
Kenner Electrics electricians find this type of cabling almost every week, most often in the post-war-era houses in the middle-aged suburbs we service, such as Ashburton, Box Hill, Mount Waverley, Burwood, Blackburn, Vermont, Glen Waverley, Mitcham, Nunawading, and Vermont.
The dangers associated with TRS cabling are similar to those associated with VIR cabling. The external rubber insulation deteriorates over time and crumbles off the conductors, leaving live electrical parts exposed.
Unfortunately, it is very common to find this type of cabling still in use despite the badly deteriorated insulation, and we regularly pull apart light switches and power points to find completely exposed electrical wires with little to no insulation left.
Any home containing TRS cabling should be rewired with modern, safe TPS cabling as soon as possible.
Thermoplastic Sheathed (TPS) Cable – late 1960s to today
The type of cabling that is currently specified in electrical safety regulations and installed throughout Melbourne is a thermoplastic sheathed (TPS) cable. These are conductors sheathed in coloured thermoplastic insulation and double-insulated with another outer layer of thermoplastic insulation.
It is the most durable type of cable and has a much longer life than the older types of cable discussed above. It also has an earth wire within the cable. Unfortunately, nothing lasts forever, so TPS cables will eventually need replacing, but you can expect many decades of safe operation.
When properly installed, the TPS cable is the safest and most modern cable. However, some dangers do arise from poor installation or DIY electrical attempts. Some older styles of TPS cabling are missing the earth wire, so they rely on a bare earth cable, which must be separately insulated if it is terminated into a power outlet or light switch.
Safety Recall of Infinity + Olsent Branded TPS Cables – 2012 to 2013
A particular brand of TPS cable has been recalled throughout Australia for not meeting Australian electrical standards. Infinity or Olsent-branded electrical cables were installed in approximately 22,000 homes in Australia from 2010 to 2013.
This brand of cabling was found to have poor-quality insulation that becomes brittle much more quickly than other types of TPS cabling. If the cables are disturbed, the insulation may break and expose live parts, creating a risk of fire or electric shock. This issue has been a concern for the Melbourne City Council, as faulty wiring can impact the electricity supply and overall safety of many homes.
While the initial batch of this cable imported from overseas met Australian Standards, subsequent batches were made with inferior products to save costs, causing it to no longer meet Australian Standards. This cable was sold mainly through Masters hardware stores and some other smaller hardware store chains, with many DIYers, builders, and frugal contractors falling victim to the appeal of cheap cable.
They should only install quality products in your home. Additionally, it is crucial to never attempt DIY electrical work, as this is illegal and poses a serious safety risk to yourself and others.
This caution extends to the maintenance of electric trams, where proper wiring and standards are essential for safe operation.
What To Do If You Think There’s Old Cabling In Your Home?
Do you know what type of cabling is in your home? Ensuring the safety of your home electrical system is a vital part of home maintenance, and the only way to be sure is to get your cabling inspected by a licensed electrician. See our blog on Old & Unsafe Wiring in Older Homes for more information on the next steps you should take.
Experienced electricians like Kenner Electrics can identify the type of cabling and provide recommendations for the best solution to keep your home and family safe. Our trusted electricians can also conduct a Home Electrical Safety Inspection to ensure that all the other electrical components in your home are safe. Give us a call today to book an inspection.
